JP4254886B2 - Organic electroluminescence device and display device - Google Patents

Description

  The present invention relates to an organic electroluminescent element and a display device, and more particularly to a red light emitting organic electroluminescent element and a display device using the same.

  In recent years, a display device using an organic electroluminescent element (so-called organic EL element) has attracted attention as a lightweight and highly efficient flat panel display device.

  An organic electroluminescent element constituting such a display device is provided on a transparent substrate made of glass or the like, for example, an anode made of ITO (Indium Tin Oxide: transparent electrode) in order from the substrate side, an organic layer, and A cathode is laminated. The organic layer has a structure in which a hole injecting layer, a hole transporting layer, and an electron transporting light emitting layer are sequentially stacked in this order from the anode side. In the organic electroluminescence device configured as described above, electrons injected from the cathode and holes injected from the anode are recombined in the light emitting layer, and light generated during the recombination is transmitted through the anode to the substrate side. Is taken out of.

  As an organic electroluminescent element, in addition to the above-described structure, a structure in which a cathode, an organic layer, and an anode are sequentially laminated in order from the substrate side, and an electrode positioned on the upper side (upper electrode as a cathode or an anode) There is also a so-called top-emitting type in which light is extracted from the upper electrode side opposite to the substrate by forming a transparent material. In particular, in an active matrix display device in which a thin film transistor (TFT) is provided on a substrate, a so-called Top Emission structure in which a top emission type organic electroluminescence element is provided on a substrate on which a TFT is formed. This is advantageous in improving the aperture ratio of the light emitting portion.

  By the way, when the practical application of the organic EL display is taken into consideration, it is necessary to improve the light emission efficiency of the organic electroluminescent element in addition to widening the opening of the organic electroluminescent element to enhance light extraction. In view of this, various materials and layer configurations for improving luminous efficiency have been studied.

For example, in the case of a red light-emitting element, a configuration in which a naphthacene derivative (including a rubrene derivative) is used as a dopant material as a new red light-emitting material replacing a conventionally known pyran derivative typified by DCJTB has been proposed ( For example, see Patent Documents 1 and 2 below).

  Patent Document 2 also proposes a configuration in which white light emission is obtained by laminating a second light-emitting layer containing a penylene derivative and an anthracene derivative on a first light-emitting layer using a rubrene derivative as a dopant material. Yes.

  Furthermore, a configuration has also been proposed in which white light emission is obtained by doping a rubrene derivative into an electron transport layer or a hole transport layer adjacent to the blue light-emitting layer (see Patent Document 3 below).

2000-26334 2003-55652 gazette (particularly, paragraphs 0353 to 0357, see Table 11) 2004-134396

  By the way, when performing full-color display in the display device as described above, organic electroluminescent elements of three colors that emit light of three primary colors (red, green, and blue) are used in an array, or organic electroluminescent elements that emit white light and each color are used. These color filters or color conversion layers are used in combination. Among these, from the viewpoint of emission light extraction efficiency, a configuration using an organic electroluminescent element that emits light of each color is advantageous.

  However, the light emission of the red light-emitting element using the naphthacene derivative (rubrene derivative) described above has a current efficiency of about 6.7 cd / A, and the emission color is orange rather than red.

  Accordingly, an object of the present invention is to provide a red light emitting organic electroluminescent element having sufficiently good luminous efficiency and color purity, and a display device using the same.

  The organic electroluminescent element of the present invention for achieving such an object is a red light emitting organic electroluminescent element in which an organic layer having a light emitting layer is sandwiched between an anode and a cathode. This light emitting layer contains a host material made of a polycyclic aromatic hydrocarbon compound having a parent skeleton of 4 to 7 members together with a red light emitting guest material. In addition, a photosensitizing layer containing a luminescent guest material that emits light in the green region is provided adjacent to the luminescent layer.

  In the organic electroluminescent device having such a configuration, as will be described in detail in the following examples, the current efficiency is increased as compared with the configuration in which the photosensitizing layer is not provided, and the light containing the light emitting material is included. It was found that only red emitted light generated in the light emitting layer without being influenced by the sensitizing layer is extracted from the device.

  The present invention is also a display device in which a plurality of organic electroluminescent elements having the above-described configuration are arranged on a substrate.

  In such a display device, as described above, since a display device using an organic electroluminescent element having high luminance and high color purity as a red light emitting element is configured, it can be combined with other green light emitting elements and blue light emitting elements. This enables full color display with high color reproducibility.

  As described above, according to the organic electroluminescent element of the present invention, it is possible to improve the luminous efficiency of red emitted light while maintaining the color purity.

  According to the display device of the present invention, as described above, a pixel is formed by combining a green light emitting element and a blue light emitting element together with an organic electroluminescent element that is a red light emitting element having high color purity and luminous efficiency. This enables full color display with high color reproducibility.

  Hereinafter, embodiments of the present invention will be described in detail in the order of an organic electroluminescent element and a display device using the same based on the drawings.

≪Organic electroluminescent element-1≫
FIG. 1 is a cross-sectional view schematically showing an organic electroluminescent element of the present invention. The organic electroluminescent element 11 shown in this figure is formed by laminating an anode 13, an organic layer 14, and a cathode 15 in this order on a substrate 12. Among these, the organic layer 14 is formed by laminating, for example, a hole injection layer 14a, a hole transport layer 14b, a light emitting layer 14c, a photosensitizing layer 14d, and an electron transport layer 14e in this order from the anode 13 side.

  The present invention is characterized by the configuration of the light emitting layer 14c and the configuration in which the photosensitizing layer 14d is provided in contact therewith. In the following, it is assumed that the organic electroluminescent element 11 having such a stacked configuration is configured as a top-emitting element that extracts light from the side opposite to the substrate 12, and details of each layer in this case are described from the substrate 12 side. These will be described in order.

<Board>
The substrate 12 is a support on which the organic electroluminescent elements 11 are arranged and formed on one main surface side, and may be a known substrate, for example, a film or sheet made of quartz, glass, metal foil, or resin. Of these, quartz and glass are preferable. In the case of resin, methacrylic resin represented by polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), poly Examples thereof include polyesters such as butylene naphthalate (PBN), polycarbonate resins, and the like, but it is necessary to perform a laminated structure and surface treatment that suppress water permeability and gas permeability.

<Anode>
The anode 13 has a large work function from the vacuum level of the electrode material in order to inject holes efficiently, for example, aluminum (Al), chromium (Cr), molybdenum (Mo), tungsten (W), copper (Cu), silver (Ag), gold (Au) metals and alloys thereof, oxides of these metals and alloys, or alloys of tin oxide (SnO ₂ ) and antimony (Sb), ITO (indium) Tin oxide), InZnO (indium zinc oxide), alloys of zinc oxide (ZnO) and aluminum (Al), and oxides of these metals and alloys are used alone or in a mixed state.

  Further, the anode 13 may have a laminated structure of a first layer having excellent light reflectivity and a second layer having a light transmittance and a high work function provided thereon.

  The first layer is made of an alloy containing aluminum as a main component. The subcomponent may include at least one element having a work function relatively smaller than that of aluminum as a main component. As such an auxiliary component, a lanthanoid series element is preferable. Although the work function of the lanthanoid series elements is not large, the inclusion of these elements improves the stability of the anode and also satisfies the hole injection property of the anode. In addition to lanthanoid series elements, elements such as silicon (Si) and copper (Cu) may be included as subcomponents.

  The content of subcomponents in the aluminum alloy layer constituting the first layer is preferably about 10 wt% or less in total for Nd, Ni, Ti, or the like that stabilizes aluminum. Thereby, while maintaining the reflectance in the aluminum alloy layer, the aluminum alloy layer can be stably maintained in the manufacturing process of the organic electroluminescent element, and further, processing accuracy and chemical stability can be obtained. In addition, the conductivity of the anode 13 and the adhesion to the substrate 12 can be improved.

  Examples of the second layer include a layer made of at least one of an oxide of an aluminum alloy, an oxide of molybdenum, an oxide of zirconium, an oxide of chromium, and an oxide of tantalum. Here, for example, when the second layer is an oxide layer of an aluminum alloy containing a lanthanoid element as a subcomponent (including a natural oxide film), the oxide of the lanthanoid element has a high transmittance, so that this is included. The transmittance of the second layer is improved. For this reason, it is possible to maintain a high reflectance on the surface of the first layer. Further, the second layer may be a transparent conductive layer such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). These conductive layers can improve the electron injection characteristics of the anode 13.

The anode 13, the side in contact with the substrate 12, may be provided a conductive layer for improving the adhesion between the anode 13 and the substrate 12. Examples of such a conductive layer include transparent conductive layers such as ITO and IZO.

  When the driving method of the display device configured using the organic electroluminescent element 11 is an active matrix method, the anode 13 is patterned for each pixel and connected to a driving thin film transistor provided on the substrate 12. It is provided in the state that was done. Further, in this case, although not shown here, an insulating film is provided on the anode 13, and the surface of the anode 13 of each pixel is exposed from the opening of the insulating film. And

<Hole injection layer>
The hole injection layer 14a is for increasing the efficiency of hole injection into the light emitting layer 14c. Examples of the material for the hole injection layer 14a include benzine, styrylamine, triphenylamine, porphyrin, triphenylene, azatriphenylene, tetracyanoquinodimethane, triazole, imidazole, oxadiazole, polyarylalkane, and phenylene. Diamine, arylamine, oxazole, fullerene, anthracene, fluorenone, hydrazone, stilbene or their derivatives, or heterocyclic conjugated monomers, oligomers such as polysilane compounds, vinylcarbazole compounds, thiophene compounds, or aniline compounds Alternatively, a polymer can be used.

  Further, specific materials for the hole injection layer 14a include α-naphthylphenylphenylenediamine, porphyrin, metal tetraphenylporphyrin, metal naphthalocyanine, C60, C70, hexacyanoazatriphenylene, 7,7,8,8. -Tetracyanoquinodimethane (TCNQ), 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (F4-TCNQ), tetracyano 4,4,4-tris (3- Methylphenylphenylamino) triphenylamine, N, N, N ′, N′-tetrakis (p-tolyl) p-phenylenediamine, N, N, N ′, N′-tetraphenyl-4,4′-diaminobiphenyl N-phenylcarbazole, 4-di-p-tolylaminostilbene, poly (paraphenylene vinylene), poly (Thiophene), poly (thiophene vinylene), poly (2,2'-thienylpyrrole), and including without being limited thereto.

<Hole transport layer>
The hole transport layer 14b is for increasing the efficiency of hole injection into the light emitting layer 14c, like the hole injection layer 14a. Such a hole transport layer 14b is configured using a material selected from the same materials as the hole injection layer 14a described above.

<Light emitting layer>
The light emitting layer 14 c is a region where holes injected from the anode 13 side and electrons injected from the cathode 15 side are recombined when a voltage is applied to the anode 13 and the cathode 15. In the present embodiment, the structure of the light emitting layer 14c is one feature. In other words, the light-emitting layer 14c uses a polycyclic aromatic hydrocarbon compound having a parent skeleton of 4 to 7 ring members as a host material, and the host material is doped with a red light-emitting guest material, Red light emission is generated.

  Among these, the host material constituting the light emitting layer 14c is a polycyclic aromatic hydrocarbon compound having a mother skeleton of 4 to 7 members, and pyrene, benzopyrene, chrysene, naphthacene, benzonaphthacene, dibenzonaphthacene, perylene. , Selected from coronen.

  The host material constituting the light emitting layer 14c is a polycyclic aromatic hydrocarbon compound having a parent skeleton having 4 to 7 ring members, and pyrene, benzopyrene, chrysene, naphthacene, benzonaphthacene, dibenzonaphthacene, perylene, coronene. It shall be selected from.

  Among these, it is preferable to use a naphthacene derivative represented by the following general formula (1) as a host material.

However, in the general formula (1), R ^{1 to} R ⁸ are each independently hydrogen, halogen, hydroxyl group, substituted or unsubstituted carbonyl group having 20 or less carbon atoms, substituted or unsubstituted carbon group having 20 or less carbon atoms. Carbonyl ester group, substituted or unsubstituted alkyl group having 20 or less carbon atoms, substituted or unsubstituted alkenyl group having 20 or less carbon atoms, substituted or unsubstituted alkoxyl group having 20 or less carbon atoms, cyano group, nitro group, carbon A substituted or unsubstituted silyl group having 30 or fewer carbon atoms, a substituted or unsubstituted aryl group having 30 or fewer carbon atoms, a substituted or unsubstituted heterocyclic group having 30 or fewer carbon atoms, or a substituted or unsubstituted carbon group having 30 or fewer carbon atoms An amino group is shown.

The aryl group represented by R ^{1 to} R ⁸ in the general formula (1) is, for example, a phenyl group, 1-naphthyl group, 2-naphthyl group, fluorenyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 1-chrycenyl group, 6-chrycenyl group, 2-fluoranthenyl group, 3-fluoranthenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, o-tolyl Group, m-tolyl group, p-tolyl group, pt-butylphenyl group and the like.

The heterocyclic group represented by R ^{1 to} R ⁸ is a 5-membered or 6-membered aromatic heterocyclic group containing O, N, or S as a hetero atom, or a condensed polycyclic aromatic complex having 2 to 20 carbon atoms. A cyclic group is mentioned. Examples of the aromatic heterocyclic group and the condensed polycyclic aromatic heterocyclic group include thienyl group, furyl group, pyrrolyl group, pyridyl group, quinolyl group, quinoxalyl group, imidazopyridyl group, and benzothiazole group. Representative examples include 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3-pyridinyl group, 4-pyridinyl group, 1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group Zofuranyl group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group Group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6-quinoxalinyl group Group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group, 1-phenanthridinyl group, 2-phenanthridinyl group, 3-phenanthridinyl group 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phenanthridinyl group, 8-phenanthridinyl group, 9 Phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group, and the like.

The amino group represented by R ^{1 to} R ⁸ may be an alkylamino group, an arylamino group, an aralkylamino group, or the like. These preferably have an aliphatic having 1 to 6 carbon atoms in total and / or an aromatic carbocyclic ring having 1 to 4 rings. Examples of such a group include a dimethylamino group, a diethylamino group, a dibutylamino group, a diphenylamino group, a ditolylamino group, a bisbiphenylylamino group, and a dinaphthylamino group.

  Two or more of the above substituents may form a condensed ring, and may further have a substituent.

  In particular, the naphthacene derivative represented by the general formula (1) is preferably a rubrene derivative represented by the following general formula (1a).

In the general formula (1a), R ^{11 to} R ¹⁵ , R ^{21 to} R ²⁵ , R ^{31 to} R ³⁵ , and R ^{41 to} R ⁴⁵ are each independently a hydrogen atom, aryl group, heterocyclic group, amino group, aryloxy A group, an alkyl group or an alkenyl group; However, R ^{11 to} R ¹⁵ , R ^{21 to} R ²⁵ , R ^{31 to} R ³⁵ , and R ^{41 to} R ⁴⁵ are preferably the same.

In general formula (1a), R ^{5 to} R ⁸ are each independently a hydrogen atom, an aryl group which may have a substituent, or an alkyl group or alkenyl group which may have a substituent. And

Preferable embodiments of the aryl group, heterocyclic group, and amino group in the general formula (1a) may be the same as R ^{1 to} R ^{8 in} the general formula (1). In the case ^{R 11 ~R 15, R 21 ~R} 25, R 31 ~R 35, R 41 ~R 45 is an amino group, an alkylamino group, and an aryl amino group or an aralkylamino group. These preferably have an aliphatic group having 1 to 6 carbon atoms or 1 to 4 aromatic carbon rings. Examples of such a group include a dimethylamino group, a diethylamino group, a dibutylamino group, a diphenylamino group, a ditolylamino group, and a bisbiphenylylamino group.

  Another specific example of the naphthacene derivative suitably used as the host material of the light emitting layer 14c is rubrene of the following compound (1) -1 which is one of the rubrene derivatives of the general formula (1a). In addition, the following compounds (1) -2 to (1) -4 are exemplified.

  Examples of the red light-emitting guest material constituting the light-emitting layer 14c include perylene derivatives represented by general formula (5), diketopyrrolopyrrole derivatives represented by general formula (6), and pyromethene complexes represented by general formula (7). , A pyran derivative of the general formula (8), or a styryl derivative of the general formula (9) is used. Hereinafter, the details of the red luminescent guest material will be described.

-Perylene derivatives-
As the red light emitting guest material, for example, a compound represented by the following general formula (5) (diindeno [1,2,3-cd] perylene derivative) is used.

However, in the general formula (5), X ^{1 to} X ²⁰ are each independently hydrogen, halogen, hydroxyl group, substituted or unsubstituted carbonyl group having 20 or less carbon atoms, substituted or unsubstituted carbon group having 20 or less carbon atoms. Carbonyl ester group, substituted or unsubstituted alkyl group having 20 or less carbon atoms, substituted or unsubstituted alkenyl group having 20 or less carbon atoms, substituted or unsubstituted alkoxyl group having 20 or less carbon atoms, cyano group, nitro group, carbon A substituted or unsubstituted silyl group having 30 or fewer carbon atoms, a substituted or unsubstituted aryl group having 30 or fewer carbon atoms, a substituted or unsubstituted heterocyclic group having 30 or fewer carbon atoms, or a substituted or unsubstituted carbon group having 30 or fewer carbon atoms An amino group is shown.

The aryl group represented by X ^{1 to} X ²⁰ in the general formula (5) is, for example, a phenyl group, 1-naphthyl group, 2-naphthyl group, fluorenyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 1-chrycenyl group, 6-chrycenyl group, 2-fluoranthenyl group, 3-fluoranthenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, o-tolyl Group, m-tolyl group, p-tolyl group, pt-butylphenyl group and the like.

The heterocyclic group represented by X ^{1 to} X ²⁰ is a 5-membered or 6-membered aromatic heterocyclic group containing O, N, or S as a hetero atom, or a condensed polycyclic aromatic heterocyclic group having 2 to 20 carbon atoms. Is mentioned. Examples of these aromatic heterocyclic groups and condensed polycyclic aromatic heterocyclic groups include thienyl group, furyl group, pyrrolyl group, pyridyl group, quinolyl group, quinoxalyl group, imidazopyridyl group, and benzothiazole group. Representative examples include 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3-pyridinyl group, 4-pyridinyl group, 1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group Zofuranyl group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group Group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6-quinoxalinyl group Group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group, 1-phenanthridinyl group, 2-phenanthridinyl group, 3-phenanthridinyl group 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phenanthridinyl group, 8-phenanthridinyl group, 9 Phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group, and the like.

The amino group represented by X ^{1 to} X ²⁰ may be any of an alkylamino group, an arylamino group, an aralkylamino group, and the like. These preferably have an aliphatic having 1 to 6 carbon atoms in total and / or an aromatic carbocyclic ring having 1 to 4 rings. Examples of such a group include a dimethylamino group, a diethylamino group, a dibutylamino group, a diphenylamino group, a ditolylamino group, a bisbiphenylylamino group, and a dinaphthylamino group.

  Two or more of the above substituents may form a condensed ring and may further have a substituent.

  Specific examples of the diindeno [1,2,3-cd] perylene derivative suitably used as a red light emitting guest material in the light emitting layer 14c include the following compounds (5) -1 to (5) -8. . However, the present invention is not limited to these.

-Diketopyrrolopyrrole derivative-
As the red light emitting guest material, for example, a compound (diketopyrrolopyrrole derivative) represented by the following general formula (6) is used.

However, in General formula (6), Y < ¹ > and Y < ² > represent an oxygen atom or a substituted or unsubstituted imino group each independently. Further, Y ³ to Y ⁸ are each independently hydrogen, halogen, of 20 or less substituted or unsubstituted alkyl group having a carbon number of 20 or less substituted or unsubstituted alkenyl group having a carbon number 30 or less substituted or unsubstituted carbon A substituted aryl group, a substituted or unsubstituted heterocyclic group having 30 or less carbon atoms, or a substituted or unsubstituted amino group having 30 or less carbon atoms is shown.

In the general formula (6), Ar ¹ and Ar ² represent a divalent group selected from a substituted or unsubstituted aromatic hydrocarbon group and a substituted or unsubstituted aromatic heterocyclic group.

Incidentally, in the general formula (6), Y ³ substituted or unsubstituted aryl group to Y ⁸ are shown, Y ³ heterocyclic group to Y ⁸ represents an amino group which further is indicated Y ³ to Y ⁸ are the general formula This is the same as the group shown for the perylene derivative in (5). Further, two or more of the above substituents may form a condensed ring, and it may also have a substituent.

  Specific examples of the diketopyrrolopyrrole derivative suitably used as the red light emitting guest material in the light emitting layer 14c include the following compounds (6) -1 to (6) -14. However, the present invention is not limited to these.

-Pyromethene complex-
As the red light emitting guest material, for example, a compound (pyromethene complex) represented by the following general formula (7) is used.

However, in General Formula (7), Z ^{1 to} Z ⁹ are each independently hydrogen, halogen, a substituted or unsubstituted alkyl group having 20 or less carbon atoms, a substituted or unsubstituted alkenyl group having 20 or less carbon atoms, A substituted or unsubstituted alkoxyl group having 20 or less carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted silyl group having 30 or less carbon atoms, a substituted or unsubstituted aryl group having 30 or less carbon atoms, a 30 or less carbon atoms A substituted or unsubstituted heterocyclic group, or a substituted or unsubstituted amino group having 30 or less carbon atoms is shown.

Incidentally, in the general formula (7), Z ¹ ~Z ⁹ is substituted or unsubstituted aryl group shown, an amino group represented by Z ¹ to Z ⁹ is a heterocyclic group represented, and Z ¹ to Z ^9, the general formula ( It is the same as the group shown for the perylene derivative of 5). Further, two or more of the above substituents may form a condensed ring, and it may also have a substituent.

  Specific examples of the pyromethene complex suitably used as the red light emitting guest material in the light emitting layer 14c include the following compounds (7) -1 to (7) -69. However, the present invention is not limited to these.

-Pyran derivatives-
As the red light-emitting guest material, for example, a compound (pyran derivative) represented by the following general formula (8) is used.

However, in General Formula (8), L ^{1 to} L ⁶ are each independently hydrogen, a substituted or unsubstituted alkyl group having 20 or less carbon atoms, a substituted or unsubstituted alkenyl group having 20 or less carbon atoms, or a carbon number. 20 or less substituted or unsubstituted alkoxyl group, cyano group, nitro group, substituted or unsubstituted silyl group having 30 or less carbon atoms, substituted or unsubstituted aryl group having 30 or less carbon atoms, substituted or unsubstituted 30 carbon atoms or less An unsubstituted heterocyclic group, or a substituted or unsubstituted amino group having 30 or less carbon atoms is shown. L ¹ and L ⁴ or L ² and L ³ may take a cyclic structure through hydrocarbon.

Incidentally, in the general formula (8), L ¹ ~L ⁶ is substituted or unsubstituted aryl group represented, L ¹ ~L ⁶ heterocyclic group represented, and an amino group represented by L ¹ ~L ⁶ the general formula ( It is the same as the group shown for the perylene derivative of 5). L ¹ and L ⁴ or L ² and L ³ may have a cyclic structure through hydrocarbon, and two or more of the above substituents may form a condensed ring and may further have a substituent. .

  The following compounds (8) -1 to (8) -7 are exemplified as specific examples of the pyran derivative suitably used as the red light emitting guest material in the light emitting layer 14c. However, the present invention is not limited to these.

-Styryl derivative-
As the red luminescent guest material, for example, a compound (styryl derivative) represented by the following general formula (9) is used.

In general formula (9), T ^{1 to} T ³ represent a substituted or unsubstituted aryl group having 30 or less carbon atoms or a substituted or unsubstituted heterocyclic group having 30 or less carbon atoms. T ⁴ represents a substituted or unsubstituted phenylene moiety that may have a cyclic structure with T ² and T ³ .

In the general formula (9), a substituted or unsubstituted aryl group represented by T ¹ through T ^3, the heterocyclic group represented by T ¹ through T ³ are the same as the group represented by the perylene derivative of the general formula (5) .

Two or more of the above substituents may form a condensed ring and may further have a substituent. In this case, examples of the group further substituted with T ^{1 to} T ⁴ include, for example, hydrogen, halogen, hydroxyl group, a substituted or unsubstituted carbonyl group having 20 or less carbon atoms, and a substituted or unsubstituted group having 20 or less carbon atoms. Carbonyl ester group, substituted or unsubstituted alkyl group having 20 or less carbon atoms, substituted or unsubstituted alkenyl group having 20 or less carbon atoms, substituted or unsubstituted alkoxyl group having 20 or less carbon atoms, cyano group, nitro group, amino group Groups and the like. In addition, the amino group may be any of an alkylamino group, an arylamino group, an aralkylamino group, and the like. These preferably have an aliphatic having 1 to 6 carbon atoms in total and / or an aromatic carbocyclic ring having 1 to 4 rings. Examples of such a group include a dimethylamino group, a diethylamino group, a dibutylamino group, a diphenylamino group, a ditolylamino group, a bisbiphenylylamino group, and a dinaphthylamino group.

  The following compounds (9) -1 to (9) -35 are exemplified as specific examples of the styryl derivative suitably used as the red light emitting guest material in the light emitting layer 14c. However, the present invention is not limited to these.

  In addition, as described above, the perylene derivative of the general formula (5), the diketopyrrolopyrrole derivative of the general formula (6), the pyromethene complex of the general formula (7) used as the red light emitting guest material in the light emitting layer 14c, The pyran derivative of the general formula (8) or the styryl derivative of the general formula (9) preferably has a molecular weight of 2000 or less, more preferably 1500 or less, and particularly preferably 1000 or less. This is because there is a concern that if the molecular weight is large, the vapor deposition property may be deteriorated when an element is formed by vapor deposition.

<Photosensitizing layer>
The photosensitizing layer 14d is a layer for transferring energy to the light emitting layer 14c and improving the light emission efficiency in the light emitting layer 14c. In the present embodiment, another feature is that such a photosensitizing layer 14d is provided in contact with the light emitting layer 14c. Such a photosensitizing layer 14d is obtained by doping a host material with a light-emitting guest material that emits light in a green region.

  Among these, as the light emitting guest material, a material having high light emission efficiency, for example, a low molecular fluorescent dye, a fluorescent polymer, and an organic light emitting material such as a metal complex are used.

  Here, the green luminescent guest material refers to a compound having a peak in the wavelength range of light emission of about 490 nm to 580 nm. Such compounds include naphthalene derivatives, anthracene derivatives, pyrene derivatives, naphthacene derivatives, fluoranthene derivatives, perylene derivatives, coumarin derivatives, quinacridone derivatives, indeno [1,2,3-cd] perylene derivatives, bis (azinyl) methene boron complexes Organic substances such as pyran dyes are used. Of these, aminoanthracene derivatives, fluoranthene derivatives, coumarin derivatives, quinacridone derivatives, indeno [1,2,3-cd] perylene derivatives, and bis (azinyl) methene boron complexes are preferred.

  The host material of the photosensitizing layer 14d is an aromatic hydrocarbon derivative having 6 to 60 carbon atoms, or an organic material formed by linking them. Specific examples thereof include naphthalene derivatives, indene derivatives, phenanthrene derivatives, pyrene derivatives, naphthacene derivatives, triphenylene derivatives, anthracene derivatives, perylene derivatives, picene derivatives, fluoranthene derivatives, acephenanthrylene derivatives, pentaphen derivatives, pentacene derivatives. Coronene derivatives, butadiene derivatives, stilbene derivatives, tris (8-quinolinolato) aluminum complexes, bis (benzoquinolinolato) beryllium complexes, and the like can be used.

  As the above host material, a host material having the highest luminous efficiency is selected and used for each luminescent guest material.

  It is important that the photosensitizing layer 14d having such a configuration is provided in contact with the light emitting layer 14c. Therefore, the photosensitizing layer 14d is not limited to be provided between the light emitting layer 14c and the cathode 15 as described above, and is provided in contact with the light emitting layer 14c between the light emitting layer 14c and the anode 13. It may be done.

<Electron transport layer>
The electron transport layer 14e is for transporting electrons injected from the cathode 15 to the light emitting layer 14c. Examples of the material for the electron transport layer 14e include quinoline, perylene, phenanthroline, bisstyryl, pyrazine, triazole, oxazole, oxadiazole, fluorenone, and derivatives or metal complexes thereof. Specifically, tris (8-hydroxyquinoline) aluminum (abbreviated as Alq3), anthracene, naphthalene, phenanthrene, pyrene, anthracene, perylene, butadiene, coumarin, acridine, stilbene, 1,10-phenanthroline, or derivatives or metal complexes thereof. Is mentioned.

  The organic layer 14 is not limited to such a layer structure, and it is sufficient that at least the light emitting layer 14c and the photosensitizing layer 14d are provided in contact therewith, and other laminated structures as required. Can be selected.

  The light emitting layer 14c may be provided in the organic electroluminescent element 11 as a hole transporting light emitting layer, an electron transporting light emitting layer, or a charge transporting light emitting layer. Furthermore, each layer constituting the organic layer 14 described above, for example, the hole injection layer 14a, the hole transport layer 14b, the light emitting layer 14c, the photosensitizing layer 14d, and the electron transport layer 14e is a laminated structure including a plurality of layers. It may be.

<Cathode>
Next, the cathode 15 provided on the organic layer 14 having such a configuration has, for example, a two-layer structure in which a first layer 15a and a second layer 15b are stacked in this order from the organic layer 14 side.

The first layer 15a is made of a material having a small work function and good light transmittance. Examples of such a material include lithium oxide (Li ₂ O) which is an oxide of lithium (Li), cesium carbonate (Cs ₂ CO ₃ ) which is a composite oxide of cesium (Cs), and further oxidation of these. Mixtures of oxides and composite oxides can be used. Further, the first layer 15a is not limited to such a material. For example, alkaline earth metals such as calcium (Ca) and barium (Ba), alkali metals such as lithium and cesium, and indium ( In), magnesium (Mg), and other metals having a low work function, and oxides and composite oxides, fluorides, and the like of these metals, alone or these metals and oxides and composite oxides, You may use it, improving stability as a mixture or an alloy.

  The second layer 15b is constituted by a thin film using a light-transmitting layer such as MgAg. The second layer 15b may be a mixed layer containing an organic light emitting material such as an aluminum quinoline complex, a styrylamine derivative, or a phthalocyanine derivative. In this case, a layer having optical transparency such as MgAg may be additionally provided as the third layer.

  In the case of the cathode 15 as described above, when the driving method of the display device configured using the organic electroluminescent element 11 is an active matrix method, the cathode 15 includes the organic layer 14 and the above-described illustration omitted here. A solid film is formed on the substrate 12 while being insulated from the anode 13 by the insulating film, and is used as a common electrode of each pixel.

  Needless to say, the cathode 15 is not limited to the laminated structure as described above, and an optimum combination and laminated structure may be adopted according to the structure of the device to be manufactured. For example, the configuration of the cathode 15 of the above embodiment includes an inorganic layer (first layer 15a) that promotes functional separation of each electrode layer, that is, electron injection into the organic layer 14, and an inorganic layer (second layer 15b) that controls the electrode. Is a laminated structure in which and are separated. However, the inorganic layer that promotes electron injection into the organic layer 14 may also serve as the inorganic layer that controls the electrode, and these layers may be configured as a single layer structure. Moreover, it is good also as a laminated structure which formed transparent electrodes, such as ITO, on this single layer structure.

  The current applied to the organic electroluminescent element 11 having the above-described configuration is usually a direct current, but a pulse current or an alternating current may be used. The current value and the voltage value are not particularly limited as long as the element is not destroyed. However, considering the power consumption and life of the organic electroluminescent element, it is desirable to emit light efficiently with as little electrical energy as possible.

  Further, when the organic electroluminescent element 11 has a cavity structure, the cathode 15 is configured using a transflective material. Then, light emitted by multiple interference between the light reflecting surface on the anode 13 side and the light reflecting surface on the cathode 15 side is extracted from the cathode 15 side. In this case, the optical distance between the light reflecting surface on the anode 13 side and the light reflecting surface on the cathode 15 side is defined by the wavelength of light to be extracted, and the film thickness of each layer is set so as to satisfy this optical distance. Suppose that it is done. In such a top emission type organic electroluminescence device, it is possible to improve the light extraction efficiency to the outside and control the emission spectrum by positively using this cavity structure.

Furthermore, although illustration is omitted here, the organic electroluminescent element 11 having such a configuration is covered with a protective layer (passivation layer) in order to prevent deterioration of the organic material due to moisture, oxygen, etc. in the atmosphere. It is preferable to use in. As the protective film, a silicon nitride (typically Si ₃ N ₄ ), a silicon oxide (typically SiO ₂ ) film, a silicon nitride oxide (SiN _x O _y : composition ratio X> Y) film, an oxide A silicon nitride (SiO _x N _y : composition ratio X> Y) film, a thin film mainly composed of carbon such as DLC (Diamond like Carbon), a CN (Carbon Nanotube) film, or the like is used. These films are preferably single-layered or laminated. Among these, a protective layer made of nitride is preferably used because it has a dense film quality and has an extremely high blocking effect against moisture, oxygen, and other impurities that adversely affect the organic electroluminescent element 11.

In the above embodiment, the present invention has been described in detail by exemplifying a case where the organic electroluminescent element is a top emission type. However, the organic electroluminescence device of the present invention is not limited to the application to the top emission type, and can be widely applied to a configuration in which an organic layer having at least a light emitting layer is sandwiched between an anode and a cathode. is there. Therefore, in order from the substrate side, the cathode, the organic layer, and the anode are laminated in sequence, and the electrode located on the substrate side (lower electrode as the cathode or anode) is made of a transparent material and located on the opposite side of the substrate The electrode (upper electrode as a cathode or anode) is made of a reflective material, so that the present invention can also be applied to an organic electroluminescence device in which light is extracted only from the lower electrode side .

  Furthermore, the organic electroluminescent element of the present invention may be an element formed by a pair of electrodes (anode and cathode) and an organic layer sandwiched between the electrodes. For this reason, it is not limited to what comprised only a pair of electrode and organic layer, and other components (for example, an inorganic compound layer and an inorganic component) coexist in the range which does not impair the effect of this invention. Is not to be excluded.

  In the organic electroluminescent element 11 configured as described above, as will be described in detail in the following examples, the current efficiency may be increased as compared with an element having no photosensitizing layer 14d. confirmed.

  Moreover, although the photosensitizing layer 14d that emits green light is stacked on the red light emitting layer 14c, color mixing due to light emission from the photosensitizing layer 14d does not occur even when an electric field is applied. Luminescence can be obtained. In the photosensitizing layer 14d, holes that have penetrated the red light emitting layer 14c and electrons injected through the electron transport layer 14e are recombined, but are released by the recombination. It is considered that this energy acts to excite electrons of the host material constituting the adjacent red light emitting layer 14c and contributes to light emission in the red light emitting layer 14c. Such a phenomenon is caused by a phenomenon in which the target red light emitting layer hardly emits light when the photosensitizing layer 14d is composed only of the host material, as shown as a comparative example for the following examples. You can analogize.

  As described above, according to the organic electroluminescent element 11 having the above-described configuration, it is possible to improve the luminous efficiency of red emitted light while maintaining the color purity.

  In addition, the luminance life of the organic electroluminescent element 11 can be improved and the power consumption can be reduced by such a significant improvement in luminous efficiency.

≪Organic electroluminescent element-2≫
FIG. 2 is a cross-sectional view schematically showing another example of the organic electroluminescent element of the present invention. The organic electroluminescent element 11 ′ shown in this figure is different from the organic electroluminescent element (11) described with reference to FIG. 1 in the configuration of the hole transport layer 14b, and other configurations are the same. To do. Next, the structure of the hole transport layer 14b in the organic electroluminescent element 11 ′ will be described.

<Hole transport layer>
The hole transport layer 14b is for increasing the efficiency of hole injection into the light emitting layer 14c, like the hole injection layer 14a. Here, in particular, the hole transport layer 14b has a laminated structure made of different materials, and at least the first hole transport layer 14b-1 on the hole injection layer 14b side and the second hole adjacent to the light emitting layer 14c. It has a laminated structure with the transport layer 14b-2.

  Among these, the 1st positive hole transport layer 14b-1 is comprised using the material selected from the materials similar to the positive hole injection layer 14a mentioned above. The first hole transport layer 14b-1 itself may have a laminated structure.

  The second hole transport layer 14b-2 is a layer provided in contact with the light emitting layer 14c, and is configured using a material different from the material composing the first hole transport layer 14b-1. Examples of the material constituting the second hole transport layer 14b-2 include a triarylamine derivative represented by general formula (2), a fluorene derivative represented by general formula (3), and a carbazole derivative represented by general formula (4) described below. Used. Details of the material constituting the second hole transport layer 14b-2 will be described below.

-Triarylamine derivative-
As a material constituting the second hole transport layer 14b-2, for example, a triarylamine derivative represented by the following general formula (2) is used.

However, A < ¹ > -A < ³ > in General formula (2) shows an aryl group or a heterocyclic group each independently, and each may be unsubstituted or may have a substituent. A ^{1 to} A ³ may each be an extended structure in which a plurality of rings are connected by a conjugated bond, but preferably have a total carbon number of 30 or less. Examples of the substituent bonded to the aryl group or heterocyclic group include hydrogen, halogen, hydroxyl group, a substituted or unsubstituted carbonyl group having 20 or less carbon atoms, and a substituted or unsubstituted carbonyl ester having 20 or less carbon atoms. Group, substituted or unsubstituted alkyl group having 20 or less carbon atoms, substituted or unsubstituted alkenyl group having 20 or less carbon atoms, substituted or unsubstituted alkoxyl group having 20 or less carbon atoms, cyano group, nitro group, or carbon number Examples include 30 or less substituted or unsubstituted amino groups.

  Specific examples of such a triarylamine derivative include the following compounds (2) -1 to (2) -48.

-Fluorene derivative-
As a material constituting the second hole transport layer 14b-2, for example, a fluorene derivative containing a pyrrolidyl skeleton represented by the following general formula (3) is used.

However, in the general formula (3), A ^{1 to} A ⁴ bonded to the pyrrolidyl skeleton and Z ¹ and Z ² bonded to the fluorene skeleton are each independently hydrogen, halogen, hydroxyl group, carbonyl group, carbonyl An ester group, an alkyl group, an alkenyl group, an alkoxyl group, a cyano group, a nitro group, and an amino group are shown. Among these, the carbonyl group, the carbonyl ester group, the alkyl group, the alkenyl group, and the alkoxyl group may be further substituted with other substituents and have 20 or less carbon atoms. Further, the amino group may be further substituted with another substituent, and has 30 or less carbon atoms.

A ^{1 to} A ⁴ bonded to the pyrrolidyl skeleton may form a cyclic structure at sites adjacent to each other.

  Here, specific examples of the pyrrolidyl skeleton are shown below.

Further, Ar ¹ and Ar ² in the general formula (3) each independently represent an aryl group or a heterocyclic group. These aryl groups or heterocyclic groups may be mono- or polysubstituted by halogen, alkyl group, alkoxy group, or aryl group, but are aryl groups having 6 to 20 carbon atoms (carbocyclic aromatic groups). Group) or a heterocyclic ring having 3 to 20 carbon atoms in total (heterocyclic aromatic group).

Preferable Ar ¹ and Ar ² are unsubstituted or monosubstituted or polysubstituted by halogen, an alkyl group having 1 to 14 carbon atoms, an alkoxy group having 1 to 14 carbon atoms, or an aryl group having 6 to 10 carbon atoms. And an aryl group having 6 to 20 carbon atoms in total.

More preferable Ar ¹ and Ar ² are unsubstituted, monosubstituted or polysubstituted with halogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an aryl group having 6 to 10 carbon atoms. And an aryl group having 6 to 16 carbon atoms in total.

Further, B ¹ and B ² in the general formula (3) represent hydrogen, an alkyl group, an aryl group, or a heterocyclic group. Of these, the alkyl group may be linear, branched, or cyclic. The aryl group may be a substituted or unsubstituted aryl group having 20 or less carbon atoms. Furthermore, the heterocyclic group may be a heterocyclic group having 20 or less carbon atoms.

  Specific examples of the substituted or unsubstituted aryl group constituting the general formula (3) above include, for example, phenyl group, 1-naphthyl group, 2-naphthyl group, 2-anthryl group, 9-anthryl. Group, 4-quinolyl group, 4-pyridyl group, 3-pyridyl group, 2-pyridyl group, 3-furyl group, 2-furyl group, 3-thienyl group, 2-thienyl group, 2-oxazolyl group, 2-thiazolyl Group, 2-benzoxazolyl group, 2-benzothiazolyl group, 2-benzoimidazolyl group, and the like, but are not limited thereto.

  Furthermore, specific examples of the alkyl group constituting the general formula (3) include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group. N-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, cyclopentyl group, n-hexyl group, 2-ethylbutyl group, 3,3-dimethylbutyl group, cyclohexyl group, n-heptyl group, cyclohexylmethyl group, Examples thereof include, but are not limited to, n-octyl group, tert-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-dodecyl group, n-tetradecyl group, n-hexadecyl group and the like. Is not to be done.

  Specific examples of the fluorene derivative as described above include the following compounds (3) -1 to (3) -20.

-Carbazole derivative-
As a material constituting the second hole transport layer 14b-2, for example, a carbazole derivative represented by the following general formula (4) is used.

However, in the general formula (4), Ar ¹ and Ar ² each independently represent an aryl group or a heterocyclic group, and these may have a substituent.

Examples of the aryl group of Ar ¹ and Ar ² include a group consisting of a benzene ring monocycle or 2 to 5 condensed rings. Specifically, a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, Examples include perylenyl groups. In addition, examples of the heterocyclic group include a 5-membered or 6-membered monocyclic ring, or a 2-5 condensed ring, and specific examples include a pyridyl group, a triazinyl group, a pyrazinyl group, a quinoxalinyl group, and a thienyl group. It is done.

  Examples of the substituent that the aryl group or heterocyclic group may have include an alkyl group (for example, a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group), and an alkenyl group (for example, a vinyl group). Straight chain or branched alkoxycarbonyl having 1 to 6 carbon atoms such as a methoxycarbonyl group or an ethoxycarbonyl group. Group), an alkoxy group (for example, a linear or branched alkoxy group having 1 to 6 carbon atoms such as a methoxy group or an ethoxy group), an aryloxy group (for example, an aryl having 6 to 10 carbon atoms such as a phenoxy group or a naphthoxy group) Oxy group), aralkyloxy group (for example, aryloxy group having 7 to 13 carbon atoms such as benzyloxy group), secondary or tertiary amino group For example, a dialkylamino group having a linear or branched alkyl group having 2 to 20 carbon atoms such as a diethylamino group or a diisopropylamino group; a diarylamino group such as a diphenylamino group or a phenylnaphthylamino group; a methylphenylamino group, An arylalkylamino group having 7 to 20 carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom), an aromatic hydrocarbon ring group (for example, phenyl group, naphthyl group, etc.) 10 aromatic hydrocarbon ring groups), and aromatic heterocyclic groups (for example, aromatic heterocyclic groups consisting of 5-membered or 6-membered monocyclic or 2-fused rings such as thienyl and pyridyl groups), etc. Is mentioned.

  Of these, alkyl groups, alkoxy groups, alkylamino groups, arylamino groups, arylalkylamino groups, halogen atoms, aryl groups (aromatic hydrocarbon ring groups), and heterocyclic groups (aromatic heterocyclic groups) are preferable. An alkyl group, an alkoxy group, and an arylamino group are particularly preferable.

When Ar ¹ and Ar ² have a structure containing three or more aromatic groups connected via two or more direct bonds, such as a terphenyl group, it is represented by —NAr ¹ Ar ^2. There is a risk of reducing the hole transporting ability of the arylamino group. Therefore, in order not to impair the properties of the compound according to the present invention, Ar1 and Ar2 are both groups in which three or more aryl groups or heterocyclic groups are not directly bonded, or short chain linkages. It is important that the groups not be connected in series via the group.

In the general formula (4), R ¹ ~R ⁸ are each independently hydrogen, halogen, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group, an acyl group, an alkoxycarbonyl group, a carboxyl group, An alkoxy group, an aryloxy group, an alkylsulfonyl group, a hydroxyl group, an amide group, an aryl group, or a heterocyclic group is shown, and a cyclic structure may be formed at an adjacent site. Further, if possible, it may be further substituted with another substituent.

Specific examples of R ^{1 to} R ⁸ include a halogen (a fluorine atom, a chlorine atom, a bromine atom or an iodine atom), an alkyl group (for example, a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group; A cycloalkyl group having 5 to 8 carbon atoms such as a cyclopentyl group and a cyclohexyl group), an aralkyl group (such as an aralkyl group having 7 to 13 carbon atoms such as a benzyl group and a phenethyl group), an alkenyl group (such as a vinyl group and an allyl group). Straight chain or branched alkenyl group having 2 to 7 carbon atoms), cyano group, amino group, especially tertiary amino group (for example, diethylamino group, diisopropylamino group, etc.). A dialkylamino group having an alkyl group; a diarylamino group such as a diphenylamino group or a phenylnaphthylamino group; a carbon such as a methylphenylamino group; An arylalkylamino group having 7 to 20 carbon atoms, an acyl group (for example, an acetyl group, a propionyl group, a benzoyl group, a naphthoyl group, etc.) containing a linear, branched or cyclic hydrocarbon group portion having 1 to 20 carbon atoms. Acyl group), alkoxycarbonyl group (for example, methoxycarbonyl group, ethoxycarbonyl group, etc., linear or branched alkoxycarbonyl group having 2 to 7 carbon atoms), carboxyl group, alkoxy group (for example, methoxy group, ethoxy group, etc., Straight chain or branched alkoxy group having 1 to 6 carbon atoms), aryloxy group (for example, aryloxy group having 6 to 10 carbon atoms such as phenoxy group and benzyloxy group), alkylsulfonyl group (for example, methylsulfonyl group, Ethylsulfonyl group, propylsulfonyl group, butylsulfonyl group, hexylsulfonyl group, etc. Alkylsulfonyl group having 1 to 6 carbon atoms), hydroxyl group, amide group (for example, methylamide group, dimethylamide group, diethylamide group, etc., alkylamide group having 2 to 7 carbon atoms; benzylamide group, dibenzylamide group, etc. Arylamide groups, etc.), aryl groups (for example, aromatic hydrocarbon ring groups consisting of a single benzene ring or 2-4 condensed rings such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group), Or a heterocyclic group (for example, a carbazolyl group, a pyridyl group, a triazyl group, a pyrazyl group, a quinoxalyl group, a thienyl group, etc., a 5-membered or 6-membered monocyclic ring or an aromatic heterocyclic group composed of 2 to 3 condensed rings ).

More preferable examples of R ^{1 to} R ⁸ include a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group (aromatic hydrocarbon ring group), and a heterocyclic group (aromatic heterocyclic group).

The groups described above as examples of R ^{1 to} R ⁸ may further have a substituent. Examples of such a substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom or an iodine atom), an alkyl group (for example, a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group), and alkenyl. A group (for example, a linear or branched alkenyl group having 1 to 6 carbon atoms such as a vinyl group or an allyl group), an alkoxycarbonyl group (for example, a linear chain having 1 to 6 carbon atoms such as a methoxycarbonyl group or an ethoxycarbonyl group) A branched alkoxycarbonyl group), an alkoxy group (for example, a straight or branched alkoxy group having 1 to 6 carbon atoms such as a methoxy group or an ethoxy group), an aryloxy group (for example, a phenoxy group or a naphthoxy group). -10 aryloxy group), dialkylamino group (for example, diethylamino group, diisopropylamino group, etc. having 2 to 2 carbon atoms) Dialkylamino group having a linear or branched alkyl group), diarylamino group (diarylamino group such as diphenylamino group or phenylnaphthylamino group), aromatic hydrocarbon ring group (for example, aromatic hydrocarbon such as phenyl group) Ring groups), aromatic heterocyclic groups (for example, aromatic heterocyclic groups consisting of 5- or 6-membered monocycles such as thienyl groups, pyridyl groups), acyl groups (for example, acetyl groups, propionyl groups, etc.) , A linear or branched acyl group having 1 to 6 carbon atoms), a haloalkyl group (for example, a linear or branched haloalkyl group having 1 to 6 carbon atoms such as a trifluoromethyl group), a cyano group, and the like. Of these, a halogen atom, an alkoxy group, and an aromatic hydrocarbon ring group are more preferable.

Moreover, R < ¹ > -R < ⁸ > may combine with adjacent things and may form the ring condensed to N-carbazolyl group. Among R ¹ to R ⁸ , the ring formed by bonding adjacent groups is usually a 5- to 8-membered ring, preferably a 5-membered ring or a 6-membered ring , more preferably a 6-membered ring. . This ring may be an aromatic ring or a non-aromatic ring, but is preferably an aromatic ring. Further, it may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring, but is preferably an aromatic hydrocarbon ring.

Examples of the N-carbazolyl group of the general formula (4) in which any of R ^{1 to} R ⁸ are bonded to form a condensed ring bonded to the N-carbazolyl group include the following.

R ^{1 to} R ⁸ particularly preferably have a structure in which all are hydrogen atoms (that is, the N-carbazolyl group is unsubstituted), or one or more of any of a methyl group, a phenyl group, and a methoxy group It is a structure in which the remainder is a hydrogen atom.

  X in the general formula (4) represents a divalent aromatic ring group. For example, it may be a linking group formed by bonding 1 to 4 arylene groups or divalent heterocyclic groups, and may be further substituted.

Such a linking group X is represented by —Ar ³ —, —Ar ⁴ —Ar ⁵ —, —Ar ⁶ —Ar ⁷ —Ar ⁸ —, or —Ar ⁹ —Ar ¹⁰ —Ar ¹¹ —Ar ¹² —. .

Ar ³ , Ar ⁴ , Ar ⁵ , Ar ⁶ , Ar ⁸ , Ar ⁹ and Ar ¹² constituting the end of the linking group X are composed of a monocyclic aromatic ring having 5 to 6 members or 2 to 5 condensed rings. Represents a divalent group and may be substituted.

Specific examples of such Ar ³ , Ar ⁴ , Ar ⁵ , Ar ⁶ , Ar ⁸ , Ar ⁹ and Ar ¹² include bivalent groups such as phenylene group, naphthylene group, anthrylene group, phenanthrylene group, pyrenylene group and peryleneylene group. And divalent aromatic heterocyclic groups such as an aromatic hydrocarbon ring group, pyridylene group, triadylene group, pyrazylene group, quinoxalylene group, thienylene group, and oxadiazolylene group.

Ar ⁷ , Ar ¹⁰ and Ar ¹¹ constituting the intermediate part of the linking group X may be the above-described divalent aromatic group similar to Ar ³ or the like, or may be a divalent arylamino group. However, when it is a divalent arylamino group, the aryl group is a 5- or 6-membered aromatic group, for example, a phenyl group, a naphthyl group, an anthryl group, a phenanthyl group, a thienyl group, a pyridyl group, a carbazolyl group. Etc., and these may have a substituent.

Ar ³ which is the smallest linking group as the linking group X is preferably 3 or more condensed rings in order to improve the rigidity of the compound and the heat resistance resulting therefrom.

Ar ⁴ , Ar ⁵ , Ar ⁶ , Ar ⁸ , Ar ⁹ and Ar ¹² constituting the end of the linking group X are preferably a single ring or 2 to 3 condensed rings, and more preferably a single ring or 2 condensed rings.

Above as the substituent which the aromatic ring may have to configure the connecting group X, for example, include the same groups as those described above as substituents for the groups exemplified as R ¹ to R ⁸ may have. Among them, an alkyl group, an alkoxy group, an aromatic hydrocarbon ring group, or an aromatic heterocyclic group is particularly preferable.

  Specific examples of the carbazole derivative as described above include the following compounds (4) -1 to (4) -26.

  The second hole transport layer 14b-2 as described above may be composed of a plurality of compounds among the organic materials represented by the general formulas (2) to (4), and is itself a laminated layer. It may be a structure.

Incidentally, in the organic electroluminescent device 11 'having a second hole transport layer 14b-2 as described above, particularly the general formula (3), to constitute a second hole transport layer 14b-1 using (4) In this case, the photosensitizing layer 14d preferably contains a hole trapping compound. Examples of the hole trapping compound include aminonaphthalene derivatives, aminoanthracene derivatives, aminochrysene derivatives, aminopyrene derivatives, styrylamine derivatives, and bis (azinyl) metheneboron complexes, which are selected and used.

  In the organic electroluminescent element 11 ′ having the second hole transport layer 14b-2 made of the material described above, as described in detail in the following examples, other than the above general formulas (2) to (4) It has been found that the initial deterioration of the luminance life is significantly improved while maintaining the luminous efficiency and the color purity, as compared with the configuration provided with the hole transport layer having a single layer structure made of the material.

  Thereby, the organic electroluminescent element 11 ′ can achieve the improvement of the luminance life and the reduction of the power consumption by the configuration provided with the photosensitizing layer 14d, similarly to the organic electroluminescent element 11 described with reference to FIG. In addition, it is possible to improve the luminance life and reduce the power consumption by specifying the stacked structure of the hole transport layer 14b.

≪Schematic configuration of display device≫
3A and 3B are diagrams illustrating an example of the display device 10 according to the embodiment. FIG. 3A is a schematic configuration diagram, and FIG. 3B is a configuration diagram of a pixel circuit. Here, an embodiment in which the present invention is applied to an active matrix display device 10 using an organic electroluminescent element 11 as a light emitting element will be described.

  As shown in FIG. 3A, a display area 12a and a peripheral area 12b are set on the substrate 12 of the display device 10. The display region 12a is configured as a pixel array section in which a plurality of scanning lines 21 and a plurality of signal lines 23 are wired vertically and horizontally, and one pixel a is provided corresponding to each intersection. Each of these pixels a is provided with one of the organic electroluminescent elements 11R (11), 11G, and 11B. In the peripheral region 12b, a scanning line driving circuit b that scans the scanning lines 21 and a signal line driving circuit c that supplies a video signal (that is, an input signal) corresponding to the luminance information to the signal lines 23 are arranged. Yes.

  As shown in FIG. 3B, the pixel circuit provided in each pixel a includes, for example, one of the organic electroluminescent elements 11R (11), 11G, and 11B, a driving transistor Tr1, and a writing transistor (sampling transistor). It is composed of Tr2 and a holding capacitor Cs. Then, the video signal written from the signal line 23 via the write transistor Tr2 is held in the holding capacitor Cs by driving by the scanning line driving circuit b, and a current corresponding to the held signal amount is supplied to each organic electroluminescent element 11R. (11), 11G, and 11B are supplied, and the organic electroluminescent elements 11R (11), 11G, and 11B emit light with luminance according to the current value.

  Note that the configuration of the pixel circuit as described above is merely an example, and a capacitor element may be provided in the pixel circuit as necessary, or a plurality of transistors may be provided to configure the pixel circuit. In addition, a necessary drive circuit is added to the peripheral region 2b according to the change of the pixel circuit.

<< Cross-sectional structure of display device-1 >>
FIG. 4 shows a first example of a cross-sectional configuration of the main part in the display area of the display device 10.

  In the display region of the substrate 12 on which the organic electroluminescent elements 11R (11), 11G, and 11B are provided, although not shown here, a driving transistor, a writing transistor, a scanning line, And a signal line (see FIG. 3), and an insulating film is provided so as to cover them.

  On the substrate 12 covered with this insulating film, organic electroluminescent elements 11R (11), 11G, and 11B are arrayed. Each of the organic electroluminescent elements 11R (11), 11G, and 11B is configured as a top-emitting element that extracts light from the side opposite to the substrate 12.

  The anode 13 of each organic electroluminescent element 11R (11), 11G, 11B is patterned for each element. Each anode 13 is connected to a drive transistor of the pixel circuit through a connection hole formed in an insulating film covering the surface of the substrate 12.

  Each anode 13 is covered with an insulating film 30 at its peripheral edge, and the central portion of the anode 13 is exposed at an opening provided in the insulating film 30. The organic layer 14 is patterned so as to cover the exposed portion of the anode 13, and the cathode 15 is provided as a common layer covering each organic layer 14.

  Among these organic electroluminescent elements 11R (11), 11G, and 11B, particularly the red light emitting element 11R is configured as the organic electroluminescent element (11) of the embodiment described with reference to FIG. On the other hand, the green light emitting element 11G and the blue light emitting element 11B may have a normal element configuration.

  That is, in the red light emitting element 11R (11), the organic layer 14 provided on the anode 13 uses, for example, the hole injection layer 14a, the hole transport layer 14b, and the naphthacene derivative as the host material in order from the anode 13 side. A red light-emitting layer 14c-R (14c), a photosensitizing layer 14d obtained by doping a host material with a light-emitting guest material that emits light in the green region, and an electron transport layer 14e are stacked.

  On the other hand, the organic layers in the green light emitting element 11G and the blue light emitting element 11B are, for example, in order from the anode 13 side, a hole injection layer 14a, a hole transport layer 14b, light emitting layers 14c-G and 14c-B for each color, and electron transport. The layer 14e is laminated in this order.

  The photosensitizing layer 14d in the red light emitting element 11R (11) is doped with a green light emitting guest material. For example, the same configuration (material) as the green light emitting layer 14c-G in the green light emitting element 11G. It may be. In addition to this, each layer other than the light emitting layers 14c-R, 14c-G, 14c-B and the photosensitizing layer 14d includes the anode 13 and the cathode 15 in each organic electroluminescent element 11R, 11G, 11B. It may be comprised with the same material, and is comprised using each material demonstrated using FIG.

  The plurality of organic electroluminescent elements 11R (11), 11G, and 11B provided as described above are covered with a protective film. The protective film is provided so as to cover the entire display area where the organic electroluminescent elements 11R, 11G, and 11B are provided.

  Here, each layer from the anode 13 to the cathode 15 constituting the red light emitting element 11R (11), the green light emitting element 11G, and the blue light emitting element 11B is formed by a vacuum deposition method, an ion beam method (EB method), a molecular beam epitaxy method. (MBE method), sputtering method, Organic Vapor Phase Deposition (OVPD) method, and other dry processes.

  For organic layers, in addition to the above methods, coating methods such as laser transfer method, spin coating method, dipping method, doctor blade method, discharge coating method, spray coating method, ink jet method, offset printing method, letterpress printing Can be formed by wet processes such as printing methods such as printing, intaglio printing, screen printing, microgravure coating, etc., depending on the properties of each organic layer and each member, It doesn't matter.

  The organic layer 14 patterned for each of the organic electroluminescent elements 11R (11), 11G, and 11B as described above is formed by, for example, a vapor deposition method or a transfer method using a mask.

  In the display device 10 of the first example configured as described above, the organic electroluminescent element (11) having the configuration of the present invention described with reference to FIG. 1 is used as the red light emitting element 11R. As described above, the red light emitting element 11R (11) has high light emission efficiency while maintaining the red light emission color. Therefore, by combining the green light emitting element 11G and the blue light emitting element 11B together with the red light emitting element 11R (11), full color display with high color expression can be performed.

  Further, the use of the organic electroluminescent element (11) having high luminous efficiency can improve the luminance life and reduce the power consumption in the display device 10. Therefore, it can be suitably used as a flat panel display such as a wall-mounted TV or a flat light emitter, and can be applied to a light source such as a copying machine or a printer, a light source such as a liquid crystal display or an instrument, a display board, a marker lamp, etc. It becomes.

<< Cross-sectional structure of display device-2 >>
FIG. 5 shows a second example of the cross-sectional configuration of the main part in the display area of the display device 10.

  The display device 10 of the second example shown in FIG. 5 is different from the first example shown in FIG. 4 in that the photosensitizing layer 14d (14c-G) and the light emitting layer 14c-G are each made of organic electroluminescence. The elements 11R (11) and 11G are formed as a common continuous pattern, and the electron transport layer 14e is formed as a continuous pattern of the common layer in all pixels, and the other configurations may be the same.

  Even in the display device 10 of the second example configured as described above, the same effect as that of the first example can be obtained. Further, in each of the organic electroluminescent elements 11R (11) and 11G, the photosensitizing layer 14d (14c-G) and the light emitting layer 14c-G are formed in a continuous pattern as a common layer, and the electron transport layer 14e is simultaneously formed in all pixels. Since the film can be formed, the manufacturing process of the display device 10 can be simplified.

<< Cross-sectional configuration of display device-3 >>
FIG. 6 shows a third example of the cross-sectional configuration of the main part in the display area of the display device 10.

  In the display device 10 of the third example shown in FIG. 6, layers other than the anode 13 and the light emitting layers 14c-R, 14c-G, and 14c-B are shared in the organic electroluminescent elements 11R (11), 11G, and 11B. The other structure may be the same as that of the second example shown in FIG. That is, as compared with the second example of FIG. 5, the hole injection layer 14a and the hole transport layer 14b below the light emitting layer are also used as the common layer.

  Even in the display device 10 of the third example configured as described above, the same effect as that of the second example can be obtained, and the manufacturing process can be further simplified as compared with the second example. .

<< Cross-sectional structure of display device-4 >>
FIG. 7 shows a fourth example of the cross-sectional configuration of the main part in the display area of the display device 10.

  As shown in this figure, the organic electroluminescent elements 11R, 11G, and 11B may have a common layer above the light emitting layers 14c-R and 14c-B. In this case, the green light emitting layer 14c-G that also serves as the photosensitizing layer 14d, the electron transport layer 14e, and the cathode 15 are formed as a continuous pattern common to the entire display region, and the others are used as patterned layers. .

  The green light emitting layer 14c-G serving as a common layer for all pixels is provided as the photosensitizing layer 14d in the red light emitting element 11R (11). On the other hand, the green light emitting layer 14c-G is also laminated on the blue light emitting element 11B. Even in such a configuration, such a configuration is adopted when the film thickness of the blue light emitting layer 14c-B is sufficiently thick, or when the blue light emitting center is localized at the interface of the hole transport layer 14b. Even in such a case, it is sufficiently possible to obtain blue light emission with good chromaticity. Further, in each of the organic electroluminescent elements 11R (11), 11G, and 11B, only the blue emitted light is extracted from the blue light emitting element 11B by configuring the structure of the organic layer as a cavity structure that extracts the emitted light of each color. You may comprise.

  In manufacturing the display device 10 having such a configuration, the layers from the green light emitting layer 14c-G (photosensitized layer 14d) to the upper layer are collectively formed on the display region using a large-diameter area mask. be able to. Therefore, the manufacturing process of the display device 10 can be simplified.

  In the fourth example, the hole injection layer 14a and the hole transport layer 14b below the light emitting layer can also be used as a common layer (continuous pattern) in the entire display region. It is possible to simplify the manufacturing process of the device 10.

  In the above first to fourth examples, the embodiment in which the present invention is applied to an active matrix display device has been described. However, the display device of the present invention can be applied to a passive matrix display device, and the same effect can be obtained.

  The display device according to the present invention described above includes a module shape having a sealed configuration as disclosed in FIG. For example, the sealing portion 31 is provided so as to surround the display region 12a that is the pixel array portion, and the sealing portion 31 is used as an adhesive and is attached to a facing portion (sealing substrate 32) such as transparent glass. Applicable to display modules. The transparent sealing substrate 32 may be provided with a color filter, a protective film, a light shielding film, and the like. The substrate 12 as a display module in which the display area 12a is formed may be provided with a flexible printed board 33 for inputting / outputting signals and the like from the outside to the display area 12a (pixel array portion).

  Further, in the above-described display device, each red light emitting element 11R may be the organic electroluminescent element 11 'described with reference to FIG. In this case, the hole transport layers of the other green light emitting elements 11G and blue light emitting elements 11B may have the same stacked structure as the red light emitting element 11R (11 ').

As the red light emitting element 11R, the organic light emitting element (11 ′) having the configuration of the present invention described with reference to FIG. 2 is used, so that the red light emitting element 11R (11 ′) has the light emission efficiency and the color purity as described above. The initial deterioration of the luminance life is kept low while maintaining the above. For this reason, by combining the red light emitting element 11R (11 ′) with the green light emitting element 11G and the blue light emitting element 11B, it is possible to perform full color display with high color expression and display with burn-in prevented. Is possible.

  In addition, the use of the organic electroluminescent element (11 ') with high luminous efficiency can improve the luminance life and reduce the power consumption in the display device 10. Therefore, it can be suitably used as a flat panel display such as a wall-mounted TV or a flat light emitter, and can be applied to a light source such as a copying machine or a printer, a light source such as a liquid crystal display or an instrument, a display board, a marker lamp, etc. It becomes.

≪Application example≫
The display device according to the present invention described above is input to various electronic devices shown in FIGS. 9 to 13 such as a digital camera, a notebook personal computer, a mobile terminal device such as a mobile phone, and a video camera. The video signal generated or the video signal generated in the electronic device can be applied to a display device of an electronic device in any field for displaying as an image or a video. An example of an electronic device to which the present invention is applied will be described below.

  FIG. 9 is a perspective view showing a television to which the present invention is applied. The television according to this application example includes a video display screen unit 101 including a front panel 102, a filter glass 103, and the like, and is created by using the display device according to the present invention as the video display screen unit 101.

  10A and 10B are diagrams showing a digital camera to which the present invention is applied. FIG. 10A is a perspective view seen from the front side, and FIG. 10B is a perspective view seen from the back side. The digital camera according to this application example includes a light emitting unit 111 for flash, a display unit 112, a menu switch 113, a shutter button 114, and the like, and is manufactured by using the display device according to the present invention as the display unit 112.

  FIG. 11 is a perspective view showing a notebook personal computer to which the present invention is applied. A notebook personal computer according to this application example includes a main body 121 including a keyboard 122 that is operated when characters and the like are input, a display unit 123 that displays an image, and the like. It is produced by using.

  FIG. 12 is a perspective view showing a video camera to which the present invention is applied. The video camera according to this application example includes a main body 131, a lens 132 for shooting an object on a side facing forward, a start / stop switch 133 at the time of shooting, a display unit 134, and the like. It is manufactured by using such a display device.

  FIG. 13 is a diagram showing a portable terminal device to which the present invention is applied, for example, a cellular phone, in which (A) is a front view in an opened state, (B) is a side view thereof, and (C) is in a closed state. (D) is a left side view, (E) is a right side view, (F) is a top view, and (G) is a bottom view. The mobile phone according to this application example includes an upper housing 141, a lower housing 142, a connecting portion (here, a hinge portion) 143, a display 144, a sub display 145, a picture light 146, a camera 147, and the like. And the sub display 145 is manufactured by using the display device according to the present invention.

  The manufacturing procedure of the organic electroluminescent element of the specific Example of this invention and a comparative example is demonstrated with reference to FIG. 1, and these evaluation results are demonstrated next.

<Examples 1-4>
An organic electroluminescent element was produced using a perylene derivative as a red light emitting guest material in the light emitting layer (see Table 1).

  First, an organic electroluminescence device for top emission, in which a 12.5 nm ITO transparent electrode is laminated on an Ag alloy (reflection layer) having a film thickness of 190 nm as an anode 13 on a substrate 12 made of a glass plate of 30 mm × 30 mm. A cell was prepared.

  Next, as a hole injection layer 14a of the organic layer 14, a film made of m-MTDATA represented by the following structural formula (101) is formed to a thickness of 12 nm (deposition rate: 0.2 to 0.4 nm / sec). However, m-MTDATA is 4,4 ′, 4 ″ -tris (phenyl-m-tolylamino) triphenylamine.

  Next, as the hole transport layer 14b, a film made of α-NPD represented by the following structural formula (102) was formed with a film thickness of 12 nm (deposition rate: 0.2 to 0.4 nm / sec). However, α-NPD is N, N′-bis (1-naphthyl) -N, N′-diphenyl [1,1′-biphenyl] -4,4′-diamine.

  Next, a light emitting layer 14c having a thickness of 30 nm was deposited on the hole transport layer 14b. At this time, rubrene of the following compound (1) -1 was used as a host material, and dibenzo [f, f ′] diindeno [1,2,3-cd: 1 ′, represented by the following compound (5) -1 was used. A 2 ′, 3′-lm] perylene derivative was doped as a red luminescent guest material at a relative film thickness ratio of 1%.

  A photosensitizing layer 14d having a thickness of 25 nm was deposited on the light emitting layer 14c thus formed. At this time, 9,10-di (2-naphthyl) anthracene (ADN) represented by the following structural formula (103) was used as a host material, and a diaminoanthracene derivative represented by the following structural formula (104) was used for green light emission. Doped as a sex guest material. The green light-emitting guest material was set to 2%, 5%, 10%, and 15% of each doping amount (relative film thickness ratio) in Examples 1 to 4.

  Next, as the electron transport layer 14e, Alq3 (8-hydroxyquinoline aluminum) represented by the following structural formula (105) was deposited with a thickness of 10 nm.

  As described above, after the organic layer 14 formed by sequentially laminating the hole injection layer 14a, the hole transport layer 14b, the light emitting layer 14c, the photosensitizing layer 14d, and the electron transport layer 14e is formed, As one layer 15a, a film made of LiF was formed with a film thickness of about 0.3 nm (deposition rate 0.01 nm / sec.) By a vacuum evaporation method. Finally, a 10 nm-thick MgAg film was formed as the second layer 15b of the cathode 15 on the first layer 15a by vacuum deposition.

  As described above, organic electroluminescent elements of Examples 1 to 4 were produced.

<Examples 5-9>
In the formation of the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent elements described in Examples 1 to 4, the materials represented by Structural Formulas (106) to (110) are used as green luminescent guest materials, respectively. A photosensitizing layer 14d was formed. The doping amount of the guest material was 5% in the relative film thickness ratio in Example 5, and 1% in the relative film thickness ratio in Examples 6 to 9. Except this, it carried out similarly to Examples 1-4.

<Comparative Example 1>
The photosensitizing layer 14d was not formed in the manufacturing procedure of the organic electroluminescent element described in Examples 1 to 4, but instead the thickness of the electron transport layer made of Alq3 (8-hydroxyquinoline aluminum) was increased to 45 nm. Turned into. Except this, it carried out similarly to Examples 1-4.

<Comparative example 2>
In the formation of the photosensitizing layer 14d in the preparation procedure of the organic electroluminescent element described in Examples 1 to 4, the photosensitizing layer 14d was formed only from the host material without doping the green light emitting guest material. Except this, it carried out similarly to Examples 1-4.

<Evaluation results>
About each organic electroluminescent element produced by the above Examples 1-9 and Comparative Examples 1 and ² , the drive voltage (V) at the time of a drive by a current density of 10 mA / cm < ² >, current efficiency (cd / A), color coordinate (X, y) was measured. The results are shown in Table 1 below.

  As shown in Table 1 above, in any of the organic electroluminescent elements of Examples 1 to 9 to which the present invention is applied, the same degree as that of the organic electroluminescent elements of Comparative Examples 1 and 2 to which the present invention is not applied. The current efficiency was nearly twice as high as that of the drive voltage. This means that the energy recombined in the photosensitizing layer 14d composed of the host material (ADN) and the luminescent guest material brings about the effect of photosensitization (increased light emission) in the light emitting layer 14c. Is shown.

  Moreover, in the organic electroluminescent elements of Examples 1 to 9, although the photosensitizing layer 14d doped with a green luminescent guest in the host was laminated on the red light emitting layer 14c, the color coordinates of the emitted light (0.64, 0.34) red light emission was observed, and there was no influence of color mixture derived from green light emission. In particular, in any of the organic electroluminescent elements of Examples 4 to 9 in which the kind of the luminescent guest material that is dopant to the photosensitizing layer 14d is changed, the color coordinates of the emitted light are (0.64, 0.34). there were. From this, it has been confirmed that according to the configuration of the present invention, red light emitted from the red light emitting layer 14c is extracted regardless of the light emitting guest material of the photosensitizing layer 14d.

<Examples 10 to 13>
An organic electroluminescent element was produced using a diketopyrrolopyrrole derivative as a red light emitting guest material in the light emitting layer (see Table 2 below).

  In the formation of the light emitting layer 14c in the manufacturing procedure of the organic electroluminescent element described in Examples 1 to 4, a diketopyrrolopyrrole derivative represented by the following compound (6) -5 is used as a red light emitting guest material. 1% doping in ratio. Except this, it carried out similarly to Examples 1-4.

<Examples 14 to 18>
In the formation of the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescence device described in Examples 10 to 13, the materials represented by the above structural formulas (106) to (110) are used as green light emitting guest materials, respectively. Thus, a photosensitizing layer 14d was formed. The doping amount of the guest material was 5% in the relative film thickness ratio in Example 14, and 1% in the relative film thickness ratio in Examples 15-18. Except this, it carried out similarly to Examples 10-13.

<Comparative Example 3>
The formation of the photosensitizing layer 14d in the preparation procedure of the organic electroluminescent device described in Examples 10 to 13 was not performed, and instead the thickness of the electron transport layer made of Alq3 (8-hydroxyquinoline aluminum) was increased to 45 nm. Turned into. Except this, it carried out similarly to Examples 10-13.

<Comparative example 4>
In the formation of the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent element described in Examples 10 to 13, the photosensitizing layer 14d was formed only from the host material without doping the green light emitting guest material. Except this, it carried out similarly to Examples 10-13.

<Evaluation results>
About each organic electroluminescent element produced by the above Examples 10-18 and Comparative Examples 3 and 4, the drive voltage (V) at the time of a drive by a current density of 10 mA / cm < ² >, current efficiency (cd / A), a color coordinate (X, y) was measured. The results are shown in Table 2 above.

  As shown in Table 2 above, in any of the organic electroluminescent elements of Examples 10 to 18 to which the present invention is applied, the same degree as that of the organic electroluminescent elements of Comparative Examples 3 and 4 to which the present invention is not applied. The current efficiency at the driving voltage was nearly twice as high. This means that the energy recombined in the photosensitizing layer 14d composed of the host material (ADN) and the luminescent guest material brings about the effect of photosensitization (increased light emission) in the light emitting layer 14c. Is shown.

  In addition, in the organic electroluminescent elements of Examples 10 to 18, the color coordinates of the emitted light despite the fact that the photosensitizing layer 14d doped with the green luminescent guest in the host was laminated on the red light emitting layer 14c. In red, red light emission was confirmed, and there was no influence of color mixture derived from green light emission. In particular, in any of the organic electroluminescent elements of Examples 14 to 18 in which the type of the luminescent guest material that is dopant to the photosensitizing layer 14d is changed, red light emission is confirmed, and the luminescent guest material of the photosensitized layer 14d is obtained. Regardless of this, it was confirmed that the red light emitted from the red light emitting layer 14c was extracted.

<Examples 19 to 22>
An organic electroluminescent element was produced using a pyromethene complex as a red light emitting guest material in the light emitting layer (see Table 3 below).

  In the formation of the light-emitting layer 14c in the manufacturing procedure of the organic electroluminescent elements described in Examples 1 to 4, a pyromethene complex represented by the following compound (7) -21 is used as a red light-emitting guest material in a relative film thickness ratio of 1 % Doping. Except this, it carried out similarly to Examples 1-4.

<Examples 23 to 27>
In the formation of the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent elements described in Examples 19 to 22, the materials represented by the above structural formulas (106) to (110) are used as green light emitting guest materials, respectively. Thus, a photosensitizing layer 14d was formed. The doping amount of the guest material was 5% in the relative film thickness ratio in Example 23 and 1% in the relative film thickness ratio in Examples 24-27. Except this, it carried out similarly to Examples 19-22.

<Comparative Example 5>
The photosensitizing layer 14d in the organic electroluminescent device preparation procedure described in Examples 19 to 22 was not formed, but instead the thickness of the electron transport layer made of Alq3 (8-hydroxyquinoline aluminum) was increased to 45 nm. Turned into. Except this, it carried out similarly to Examples 19-22.

<Comparative Example 6>
In the formation of the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent element described in Examples 19 to 22, the photosensitizing layer 14d was formed only from the host material without doping the green light emitting guest material. Except this, it carried out similarly to Examples 19-22.

<Evaluation results>
About each organic electroluminescent element produced by the above Examples 19-27 and Comparative Examples 5 and 6, the drive voltage (V) at the time of a drive at a current density of 10 mA / cm < ² >, a current efficiency (cd / A), a color coordinate (X, y) was measured. The results are shown in Table 3 above.

  As shown in Table 3 above, in any of the organic electroluminescent elements of Examples 19 to 27 to which the present invention is applied, the same degree as that of the organic electroluminescent elements of Comparative Examples 5 and 6 to which the present invention is not applied. The current efficiency was as high as 2.5 times or more at a driving voltage of. This means that the energy recombined in the photosensitizing layer 14d composed of the host material (ADN) and the luminescent guest material brings about the effect of photosensitization (increased light emission) in the light emitting layer 14c. Is shown.

  Moreover, in the organic electroluminescent elements of Examples 19 to 27, although the photosensitizing layer 14d doped with a green luminescent guest in the host was laminated on the red light emitting layer 14c, the color coordinates of the emitted light In red, red light emission was confirmed, and there was no influence of color mixture derived from green light emission. In particular, in any of the organic electroluminescent elements of Examples 23 to 27 in which the type of the luminescent guest material that is dopant to the photosensitizing layer 14d is changed, red light emission was confirmed, and the luminescent guest material of the photosensitized layer 14d was used. Regardless of this, it was confirmed that the red light emitted from the red light emitting layer 14c was extracted.

<Examples 28 to 31>
An organic electroluminescent element was prepared using a pyran derivative as a red light emitting guest material in the light emitting layer (see Table 4 below).

  In the formation of the light emitting layer 14c in the manufacturing procedure of the organic electroluminescent element described in Examples 1 to 4, as a red light emitting guest material, a pyran derivative represented by the following compound (8) -2 is 1 in relative film thickness ratio. % Doping. Except this, it carried out similarly to Examples 1-4.

<Examples 32-36>
In the formation of the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent device described in Examples 28 to 31, the materials represented by the structural formulas (106) to (110) are used as green light-emitting guest materials, respectively. Thus, a photosensitizing layer 14d was formed. The doping amount of the guest material was 5% in the relative film thickness ratio in Example 32 and 1% in the relative film thickness ratio in Examples 33 to 36. Except this, it carried out similarly to Examples 28-31.

<Comparative Example 7>
The photosensitizing layer 14d in the organic electroluminescent device preparation procedure described in Examples 28 to 31 was not formed, and instead the thickness of the electron transport layer made of Alq3 (8-hydroxyquinoline aluminum) was increased to 45 nm. Turned into. Except this, it carried out similarly to Examples 28-31.

<Comparative Example 8>
In the formation of the photosensitizing layer 14d in the production procedure of the organic electroluminescent element described in Examples 28 to 31, the photosensitizing layer 14d was formed only from the host material without doping the green light emitting guest material. Except this, it carried out similarly to Examples 28-31.

<Evaluation results>
About each organic electroluminescent element produced by the above Examples 28-36 and the comparative examples 7 and 8, the drive voltage (V) at the time of a drive by a current density of 10 mA / cm < ² >, current efficiency (cd / A), a color coordinate (X, y) was measured. The results are shown in Table 4 above.

  As shown in Table 4, in any of the organic electroluminescent elements of Examples 28 to 36 to which the present invention is applied, the driving is comparable to the organic electroluminescent elements of Comparative Examples 7 and 8 to which the present invention is not applied. The current efficiency at voltage was 3 times higher. This means that the energy recombined in the photosensitizing layer 14d composed of the host material (ADN) and the luminescent guest material brings about the effect of photosensitization (increased light emission) in the light emitting layer 14c. Is shown.

  Moreover, in the organic electroluminescent elements of Examples 28 to 36, the color coordinates of the emitted light were obtained despite the fact that the photosensitizing layer 14d doped with the green luminescent guest in the host was laminated on the red light emitting layer 14c. In red, red light emission was confirmed, and there was no influence of color mixture derived from green light emission. In particular, in any of the organic electroluminescent elements of Examples 32 to 36 in which the type of the luminescent guest material that is dopant to the photosensitizing layer 14d is changed, red light emission was confirmed, and the luminescent guest material of the photosensitized layer 14d was used. Regardless of this, it was confirmed that the red light emitted from the red light emitting layer 14c was extracted.

<Examples 37 to 40>
An organic electroluminescent element was prepared using a styryl derivative as a red light emitting guest material in the light emitting layer (see Table 5 below).

  In the formation of the light emitting layer 14c in the manufacturing procedure of the organic electroluminescent element described in Examples 1 to 4, a styryl derivative represented by the following compound (9) -21 is used as a red light emitting guest material in a relative film thickness ratio of 1 % Doping. Except this, it carried out similarly to Examples 1-4.

<Examples 41 to 45>
In the formation of the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent elements described in Examples 37 to 40, the materials represented by the structural formulas (106) to (110) are used as green light-emitting guest materials, respectively. Thus, a photosensitizing layer 14d was formed. The doping amount of the guest material was 5% in the relative film thickness ratio in Example 41 and 1% in the relative film thickness ratio in Examples 42 to 45. Except this, it carried out similarly to Examples 37-40.

<Comparative Example 9>
The photosensitizing layer 14d in the organic electroluminescent device preparation procedure described in Examples 37 to 40 was not formed, but instead the electron transport layer made of Alq3 (8-hydroxyquinoline aluminum) was thickened to 45 nm. Turned into. Except this, it carried out similarly to Examples 37-40.

<Comparative Example 10>
In the formation of the photosensitizing layer 14d in the preparation procedure of the organic electroluminescent elements described in Examples 37 to 40, the photosensitizing layer 14d was formed only from the host material without doping the green light emitting guest material. Except this, it carried out similarly to Examples 37-40.

<Evaluation results>
About each organic electroluminescent element produced by the above Examples 37-45 and Comparative Examples 9 and 10, the drive voltage (V) at the time of a drive by a current density of 10 mA / cm < ² >, a current efficiency (cd / A), a color coordinate (X, y) was measured. The results are shown in Table 5 above.

  As shown in Table 5, in any of the organic electroluminescent elements of Examples 37 to 45 to which the present invention is applied, the driving is comparable to the organic electroluminescent elements of Comparative Examples 9 and 10 to which the present invention is not applied. The current efficiency was nearly twice as high as the voltage. This means that the energy recombined in the photosensitizing layer 14d composed of the host material (ADN) and the luminescent guest material brings about the effect of photosensitization (increased light emission) in the light emitting layer 14c. Is shown.

  Moreover, in the organic electroluminescent elements of Examples 37 to 45, the color coordinates of the emitted light were obtained despite the fact that the photosensitizing layer 14d in which the green luminescent guest was doped in the host was laminated on the red light emitting layer 14c. In red, red light emission was confirmed, and there was no influence of color mixture derived from green light emission. In particular, in any of the organic electroluminescent elements of Examples 41 to 45 in which the type of the luminescent guest material that is dopant to the photosensitizing layer 14d is changed, red light emission was confirmed, and the luminescent guest material of the photosensitized layer 14d was used. Regardless of this, it was confirmed that the red light emitted from the red light emitting layer 14c was extracted.

  From the evaluation results of the respective examples and comparative examples described above, a material selected from known organic materials as a host material and a dopant material constituting the red light-emitting layer 14c is used, and is made adjacent to the light-emitting layer 14c. In the structure of the present invention provided with the photosensitizing layer 14d containing various green coloring guests, the luminous efficiency (current efficiency) can be greatly improved while maintaining the red color purity. It was confirmed that it was possible.

  This also shows that a full-color display with high color reproducibility can be achieved by configuring a pixel by combining a green light emitting element and a blue light emitting element together with the organic electroluminescent element.

<Examples 46 to 57>
The organic electroluminescent element described with reference to FIG. 2 was produced. Here, the hole transport layer 14b was formed as the following laminated structure in the manufacturing procedure of the organic electroluminescent element described in Examples 1 to 4, and the other processes were performed in the same manner as in Examples 1 to 4. . The doping amount of the guest material having the structural formula (104) in the photosensitizing layer 14d was 5% in the same relative film thickness ratio as in Example 2.

  That is, in the formation of the hole transport layer 14b, first, as the first hole transport layer 14b-1, a film made of α-NPD shown in the previous structural formula (102) is formed to a film thickness of 6 nm (deposition rate: 0.2). ˜0.4 nm / sec).

  Next, as the second hole transport layer 14b-2, a film made of 12 kinds of the following compounds selected from the compounds (2) -1 to (2) -48 in Example 46 to Example 57 was formed to a thickness of 6 nm. (Vapor deposition rate 0.2 to 0.4 nm / sec).

<Evaluation results>
About each organic electroluminescent element produced in the above Examples 46-57, the drive voltage (V), current efficiency (cd / A), and color coordinate (x, y) at the time of a drive by a current density of 10 mA / cm2 are measured. did. Further, as a burn-in index, a luminance reduction rate after 100 hours at a current density of 30 mA / cm 2 and a duty of 75% driving was measured. These results are shown in Table 6 below. Table 6 shows the measurement results of Example 2 in which the hole transport layer 14b has a single layer structure compared to Examples 46 to 57 in which the hole transport layer 14b has a laminated structure. Are shown together.

  As shown in Table 6 above, all of the organic electroluminescent elements of Examples 46 to 57 in which the hole transport layer 14b is configured as a specific laminated structure using the material of the general formula (2) are used for hole transport. Compared with the organic electroluminescent element of Example 2 in which the layer 14b has a single-layer structure, the current efficiency is maintained at the same driving voltage, and the luminance reduction rate after 100 hours at Duty 75% driving is reduced. . This indicates that the charge balance required for recombination of holes and electrons in the light emitting layer 14c is adjusted, and the effect of preventing temporal reduction in luminance is brought about.

  Moreover, in the organic electroluminescent elements of Examples 46 to 57, although the photosensitizing layer 14d doped with a green luminescent guest in the host was laminated on the red light emitting layer 14c, the color coordinates of the emitted light (0.64, 0.34) red light emission was observed, and there was no influence of color mixture derived from green light emission. From this, it was also confirmed that according to the configuration of the present invention, red light emitted from the red light emitting layer 14c is extracted regardless of the light emitting guest material of the photosensitizing layer 14d.

  From the above, by applying the present invention as a specific laminated structure using the material of the general formula (2) to form the hole transport layer 14b, initial deterioration of the luminance life while maintaining the light emission efficiency and the color purity. It was confirmed that can be improved significantly.

<Examples 58 to 62>
The organic electroluminescent element described with reference to FIG. 2 was produced. Here, the hole transport layer 14b was formed as the following laminated structure in the manufacturing procedure of the organic electroluminescent element described in Examples 1 to 4, and the other processes were performed in the same manner as in Examples 1 to 4. . The doping amount of the guest material having the structural formula (104) in the photosensitizing layer 14d was 5% in the same relative film thickness ratio as in Example 2.

  That is, in the formation of the hole transport layer 14b, first, as the first hole transport layer 14b-1, a film made of α-NPD shown in the previous structural formula (102) is formed to a film thickness of 6 nm (deposition rate: 0.2). ˜0.4 nm / sec).

  Next, as the second hole transport layer 14b-2, a film made of the following five compounds selected from the compounds (3) -1 to (3) -20 in Example 58 to Example 62 was formed to a film thickness of 6 nm. (Vapor deposition rate 0.2 to 0.4 nm / sec).

<Evaluation results>
About each organic electroluminescent element produced in the above Examples 58-62, the drive voltage (V), current efficiency (cd / A), and color coordinate (x, y) at the time of a drive by a current density of 10 mA / cm2 are measured. did. Further, as a burn-in index, a luminance reduction rate after 100 hours at a current density of 30 mA / cm 2 and a duty of 75% driving was measured. These results are shown in Table 7 below. Table 7 shows the measurement results of Example 2 in which the hole transport layer 14b has a single layer structure compared to Examples 46 to 57 in which the hole transport layer 14b has a laminated structure. Are shown together.

  As shown in Table 7 above, all of the organic electroluminescent elements of Examples 58 to 62 in which the hole transport layer 14b is configured as a specific laminated structure using the material of the general formula (3) are used for hole transport. Compared with the organic electroluminescent element of Example 2 in which the layer 14b has a single-layer structure, the current efficiency is maintained at the same driving voltage, and the luminance reduction rate after 100 hours at Duty 75% driving is reduced. . This indicates that the charge balance required for recombination of holes and electrons in the light emitting layer 14c is adjusted, and the effect of preventing temporal reduction in luminance is brought about.

  Moreover, in the organic electroluminescent element of Examples 58-62, although the photosensitizing layer 14d which doped the green luminescent guest in the host was laminated | stacked on the red light emitting layer 14c, the color coordinate of emitted light (0.64, 0.34) red light emission was observed, and there was no influence of color mixture derived from green light emission. From this, it was also confirmed that according to the configuration of the present invention, red light emitted from the red light emitting layer 14c is extracted regardless of the light emitting guest material of the photosensitizing layer 14d.

  From the above, by applying the present invention as a specific laminated structure using the material of the general formula (3) to form the hole transport layer 14b, initial deterioration of the luminance life while maintaining the luminous efficiency and color purity. It was confirmed that can be improved significantly.

<Examples 63 to 69>
The organic electroluminescent element described with reference to FIG. 2 was produced. Here, the hole transport layer 14b was formed in the following laminated structure in the manufacturing procedure of the organic electroluminescent element described in Examples 1 to 4, and the other processes were performed in the same manner as in Examples 1 to 4. . The doping amount of the guest material having the structural formula (104) in the photosensitizing layer 14d was 5% in the same relative film thickness ratio as in Example 2.

  That is, in the formation of the hole transport layer 14b, first, as the first hole transport layer 14b-1, a film made of α-NPD shown in the previous structural formula (102) is formed to a film thickness of 6 nm (deposition rate: 0.2). ˜0.4 nm / sec).

  Next, as the second hole transport layer 14b-2, a film made of the following seven compounds selected from the compounds (4) -1 to (4) -26 in Example 63 to Example 69 was formed to a thickness of 6 nm. (Vapor deposition rate 0.2 to 0.4 nm / sec).

<Evaluation results>
About each organic electroluminescent element produced in the above Examples 63-69, the drive voltage (V), current efficiency (cd / A), and color coordinate (x, y) at the time of a drive by a current density of 10 mA / cm2 are measured. did. Further, as a burn-in index, a luminance reduction rate after 100 hours at a current density of 30 mA / cm 2 and a duty of 75% driving was measured. These results are shown in Table 8 below. Table 8 shows the measurement results of Example 2 in which the hole transport layer 14b has a single layer structure with respect to Examples 46 to 57 in which the hole transport layer 14b has a laminated structure. Are shown together.

  As shown in Table 8 above, all of the organic electroluminescent elements of Examples 63 to 69 in which the hole transport layer 14b is configured as a specific stacked structure using the material of the general formula (4) are used for hole transport. Compared with the organic electroluminescent element of Example 2 in which the layer 14b has a single-layer structure, the current efficiency is maintained at the same driving voltage, and the luminance reduction rate after 100 hours at Duty 75% driving is reduced. . This indicates that the charge balance required for recombination of holes and electrons in the light emitting layer 14c is adjusted, and the effect of preventing temporal reduction in luminance is brought about.

  Moreover, in the organic electroluminescent elements of Examples 63 to 69, the color coordinates of the emitted light were obtained despite the fact that the photosensitizing layer 14d in which the green luminescent guest was doped in the host was laminated on the red light emitting layer 14c. (0.64, 0.34) red light emission was observed, and there was no influence of color mixture derived from green light emission. From this, it was also confirmed that according to the configuration of the present invention, red light emitted from the red light emitting layer 14c is extracted regardless of the light emitting guest material of the photosensitizing layer 14d.

  From the above, by applying the present invention as a specific laminated structure using the material of the general formula (4) to form the hole transport layer 14b, initial deterioration of the luminance life while maintaining the light emission efficiency and the color purity. It was confirmed that can be improved significantly.

<Examples 70 to 73>
A display device using an organic electroluminescent element similar to those in Examples 46, 52, 58, and 63 was produced as follows (see FIG. 6).

First, the anode 13 was patterned on the display area of the substrate 12, and the insulating film 30 having an opening exposing the center of each anode 13 was formed. Next, after forming the hole injection layer 14a using a large-aperture mask having an opening corresponding to the entire display region, in Example 70, the hole transport layer 14b similar to Example 46 is formed. In Example 71, the same hole transport layer 14b as in Example 52 was formed, in Example 72, the same hole transport layer 14b as in Example 58 was formed, and in Example 73, the same hole transport as in Example 63 was formed. Layer 14b was formed .

  Next, a light emitting layer 14c (14c-R) was formed in the red area only in the same manner as in Example 1, using a stripe mask having an opening corresponding to the red light emitting element formation area (red area). In addition, the light emitting layer 14c-B in the blue area was formed using a stripe mask having an opening corresponding to the formation area (blue area) of the blue light emitting element.

  After the red light-emitting layer 14c (14c-R) is formed, the photosensitizing layer 14d is formed in the same manner as in Example 1 by using a stripe-shaped mask having an intermediate opening having openings corresponding to the red area and the green area. A green light emitting layer 14c-G that also serves as a film was formed.

  Next, an electron transport layer 14e was formed in the same manner as in Example 1 using a large-aperture mask having openings corresponding to the entire display area, and a two-layered cathode 15 was formed.

  As described above, in Example 70, the organic electroluminescent element of Example 46 in which the configuration of the present invention is applied to the red area is formed as a red light emitting element, the green light emitting element is formed in the green area, and the blue light is emitted in the blue area. A display device in which the element was formed was obtained.

  In Example 71, the organic electroluminescent element of Example 52 in which the configuration of the present invention is applied to the red area is formed as a red light emitting element, the green light emitting element is formed in the green area, and the blue light emitting element is formed in the blue area. A display device in which was formed was obtained.

  Furthermore, in Example 72, the organic electroluminescent element of Example 58 in which the structure of the present invention is applied to the red area is formed as a red light emitting element, the green light emitting element is formed in the green area, and the blue light emitting element is formed in the blue area. A formed display device was obtained.

  In Example 73, the organic electroluminescent element of Example 63 in which the configuration of the present invention is applied to the red area is formed as a red light emitting element, the green light emitting element is formed in the green area, and the blue light emitting element is formed in the blue area. A display device in which was formed was obtained.

  When a specific fixed screen was displayed using these display devices and red image sticking was evaluated, image sticking was not confirmed in any of the display devices of Examples 70 to 73.

It is sectional drawing of the organic electroluminescent element of embodiment. It is sectional drawing which shows the other example of the organic electroluminescent element of this invention. It is a figure which shows an example of the circuit structure of the display apparatus of embodiment. It is a figure which shows the 1st example of the cross-sectional structure of the principal part in the display apparatus of embodiment. It is a figure which shows the 2nd example of the cross-sectional structure of the principal part in the display apparatus of embodiment. It is a figure which shows the 3rd example of the cross-sectional structure of the principal part in the display apparatus of embodiment. It is a figure which shows the 4th example of the cross-sectional structure of the principal part in the display apparatus of embodiment. It is a block diagram which shows the module-shaped display apparatus of the sealed structure to which this invention is applied. It is a perspective view which shows the television to which this invention is applied. It is a figure which shows the digital camera to which this invention is applied, (A) is the perspective view seen from the front side, (B) is the perspective view seen from the back side. 1 is a perspective view showing a notebook personal computer to which the present invention is applied. It is a perspective view which shows the video camera to which this invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the portable terminal device to which this invention is applied, for example, a mobile telephone, (A) is the front view in the open state, (B) is the side view, (C) is the front view in the closed state , (D) is a left side view, (E) is a right side view, (F) is a top view, and (G) is a bottom view.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Display apparatus, 11, 11 '... Organic electroluminescent element, 11R ... Red light emitting element, 11B ... Blue light emitting element (blue light emitting organic electroluminescent element), 11G ... Green light emitting element (green light emitting organic electroluminescent element) , 12 ... substrate, 13 ... anode, 14 ... organic layer, 14b ... hole transport layer, 14b-1 ... first hole transport layer, 14b-2 ... second hole transport layer, 14c ... light emitting layer, 14d ... Photosensitizing layer, 15 ... cathode

Claims (10)

In a red light-emitting organic electroluminescent element formed by sandwiching an organic layer having a light-emitting layer between an anode and a cathode,
The light emitting layer contains a host material made of a polycyclic aromatic hydrocarbon compound having a ring skeleton of 4 to 7 together with a red light emitting guest material,
Photosensitizing layer containing a light emitting guest material which emits light in the green region is provided et al are adjacent to the light emitting layer,
The hole transport layer provided adjacent to the light-emitting layer has a laminated structure of different material layers, and the layer adjacent to the light-emitting layer has the following general formula (2), general formula (3), or general formula An organic electroluminescent device comprising the organic material shown in (4) .

A ^{1 to} A ³ in the general formula (2) each independently represents an aryl group or a heterocyclic group.

In general formula (3),
A ^{1 to} A ⁴ , Z ¹ and Z ² are each independently hydrogen, halogen, hydroxyl group, carbonyl group, carbonyl ester group, alkyl group, alkenyl group, alkoxyl group, cyano group, nitro group or amino group. Show
A ^{1 to} A ⁴ may constitute a cyclic structure at sites adjacent to each other,
Ar ¹ and Ar ² each independently represents an aryl group or a heterocyclic group,
B ¹ and B ² represent hydrogen, an alkyl group, an aryl group, or a heterocyclic group.

In general formula (4),
Ar ¹ and Ar ² each independently represents an aryl group or a heterocyclic group,
R ^{1 to} R ⁸ are each independently hydrogen, halogen, alkyl group, aralkyl group, alkenyl group, cyano group, amino group, acyl group, alkoxycarbonyl group, carboxyl group, alkoxy group, aryloxy group, alkylsulfonyl A group, a hydroxyl group, an amide group, an aryl group, or a heterocyclic group, and may form a cyclic structure at an adjacent site;
X represents a divalent aromatic ring group. The organic electroluminescent device according to claim 1, wherein
The mother skeleton of the polycyclic aromatic hydrocarbon compound constituting the host material of the light emitting layer is selected from pyrene, benzopyrene, chrysene, naphthacene, benzonaphthacene, dibenzonaphthacene, perylene, coronene Organic electroluminescent device. The organic electroluminescent element according to claim 1 or 2 ,
A compound represented by the following general formula (1) is used as a host material for the light emitting layer.

However, in the general formula (1), R ^{1 to} R ⁸ are each independently hydrogen, halogen, hydroxyl group, substituted or unsubstituted carbonyl group having 20 or less carbon atoms, substituted or unsubstituted carbon group having 20 or less carbon atoms. Carbonyl ester group, substituted or unsubstituted alkyl group having 20 or less carbon atoms, substituted or unsubstituted alkenyl group having 20 or less carbon atoms, substituted or unsubstituted alkoxyl group having 20 or less carbon atoms, cyano group, nitro group, carbon A substituted or unsubstituted silyl group having 30 or fewer carbon atoms, a substituted or unsubstituted aryl group having 30 or fewer carbon atoms, a substituted or unsubstituted heterocyclic group having 30 or fewer carbon atoms, or a substituted or unsubstituted carbon group having 30 or fewer carbon atoms An amino group is shown. In the organic electroluminescent element in any one of Claims 1-3,
The organic electroluminescent element, wherein the photosensitizing layer is provided adjacent to the light emitting layer and between the light emitting layer and the cathode. In the organic electroluminescent element in any one of Claims 1-4 ,
The organic electroluminescence device, wherein red light emitted from the light emitting layer is extracted from one side of the anode or cathode due to multiple interference in any layer between the anode and cathode. In the organic electroluminescent element in any one of Claims 1-5 ,
A perylene derivative, a diketopyrrolopyrrole derivative, a pyromethene complex, a pyran derivative, or a styryl derivative is used as a red light emitting guest material contained in the light emitting layer. In a display device in which a plurality of red light emitting organic electroluminescent elements formed by sandwiching an organic layer having a light emitting layer between an anode and a cathode are formed on a substrate,
The light emitting layer contains a host material made of a polycyclic aromatic hydrocarbon compound having a ring skeleton of 4 to 7 together with a red light emitting guest material,
Photosensitizing layer containing a light emitting guest material which emits light in the green region is provided et al are adjacent to the light emitting layer,
The hole transport layer provided adjacent to the light-emitting layer has a laminated structure of different material layers, and the layer adjacent to the light-emitting layer has the following general formula (2), general formula (3), or general formula A display device comprising the organic material shown in (4) .

A ^{1 to} A ³ in the general formula (2) each independently represents an aryl group or a heterocyclic group.

In general formula (3) ,
A ^{1 to} A ⁴ , Z ¹ and Z ² are each independently hydrogen, halogen, hydroxyl group, carbonyl group, carbonyl ester group, alkyl group, alkenyl group, alkoxyl group, cyano group, nitro group or amino group. Show
A ^{1 to} A ⁴ may constitute a cyclic structure at sites adjacent to each other,
Ar ¹ and Ar ² each independently represents an aryl group or a heterocyclic group,
B ¹ and B ² represent hydrogen, an alkyl group, an aryl group, or a heterocyclic group.

In general formula (4),
Ar ¹ and Ar ² each independently represents an aryl group or a heterocyclic group,
R ^{1 to} R ⁸ are each independently hydrogen, halogen, alkyl group, aralkyl group, alkenyl group, cyano group, amino group, acyl group, alkoxycarbonyl group, carboxyl group, alkoxy group, aryloxy group, alkylsulfonyl A group, a hydroxyl group, an amide group, an aryl group, or a heterocyclic group, and may form a cyclic structure at an adjacent site;
X represents a divalent aromatic ring group. The display device according to claim 7 , wherein
The organic electroluminescent element is provided as a red light emitting element in a part of a plurality of pixels. The display device according to claim 8 , wherein
The photosensitizing layer of the organic electroluminescent element provided as the red light emitting element has a continuous pattern shape over a plurality of pixels as a light emitting layer in an organic electroluminescent element other than the red light emitting element provided on the substrate. A display device comprising: The display device according to claim 8 or 9 ,
A display device, wherein a blue light-emitting organic electroluminescent element and a green light-emitting organic electroluminescent element are provided on the substrate together with the red light-emitting element.

Images