JP2014107173A - Light-emitting device and method for reducing luminance distribution of light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the luminance distribution in the light-emitting face of an organic light-emitting element, and to provide a light-emitting device using such an organic light-emitting element.SOLUTION: In a light-emitting device having an emitting region consisting of a plurality of light-emitting parts having a minimum width of 0.1-10 μm and connected electrically in parallel, the emitting region includes a planar conductor 12, an insulation layer 13 formed on the upper surface thereof, a plurality of apertures 17, a plurality of first electrodes 14, an organic compound layer 15 including a luminous layer, and a second electrode 16. The plurality of apertures 17 have an elongated shape having a long axis and a short axis orthogonal to each other in the plan view, the plurality of first electrodes 14 consists of two kinds of electrodes A and B of different shapes having a long axis and a short axis orthogonal to each other. The distance between the apertures 17 in the short axis direction is longer than the length of the short axis of the first electrode A, but shorter than the length of the short axis of the first electrode B.

Description

  The present invention relates to a light emitting device using an organic light emitting element that emits light by applying a voltage to an organic compound layer including a light emitting layer sandwiched between a pair of electrodes, and a method for reducing the luminance distribution of the light emitting device.

  Organic light-emitting elements using organic compounds as light emitters are expected to be applied to lighting applications in recent years because of their high luminous efficiency and long lifetime, and research on increasing the area has been actively conducted. A planar light-emitting body used as illumination is obtained by forming an organic compound layer with a uniform thickness on a planar electrode having a smooth surface and covering it with a counter electrode.

Patent Document 1 discloses an organic light-emitting element in which an insulating layer is provided on an electrode, a non-light-emitting region is formed in a light-emitting surface, and the luminance is controlled by controlling the density of the non-light-emitting region.
On the other hand, in Patent Document 2, a dielectric layer is disposed between a hole injection electrode layer and an electron injection electrode layer, and an electroluminescent layer is formed inside a cavity formed so as to penetrate the dielectric layer. Arranged light emitting elements are disclosed.

JP2007-294441 Special table 2010-509729

By the way, in the planar light emitting body, as the area of the light emitting surface is increased, the luminance unevenness due to the internal resistance of the electrode is reduced, and conversely, the luminance of a desired region is made higher than the surroundings. It is necessary to easily control the luminance within the light emitting surface.
However, for example, in the case of the technique disclosed in Patent Document 1, it is not easy to form such a complicated insulating layer pattern on the entire surface, particularly in the case of a large-area planar light emitter.
In addition, the light emitting element described in Patent Document 2 can also be a pseudo surface light emitter that looks like a surface light emitter by arranging a plurality of fine cavities that are light emitting portions on the hole injection electrode layer. . However, in this case, since the electrodes are common to the plurality of light emitting units, it is not easy to control the luminance.

Here, when trying to adopt a method of adjusting the luminance unevenness by changing the formation density of the cavity,
(1) A distribution of formation density suitable for canceling the luminance distribution, a design of a cavity having an arrangement,
(2) Fabrication of an element having the designed cavity structure,
Therefore, it is necessary to prepare a mask or the like every time the cavity is formed.

An object of the present invention is to provide a light-emitting device using an organic light-emitting element that can easily control the luminance distribution in the light-emitting surface of the organic light-emitting element and can be easily manufactured.
More specifically, the present invention provides an organic EL device using an organic EL element that does not require reworking of a mask necessary for the above-described conventional technique in order to eliminate luminance unevenness of the organic EL element having a cavity structure. .

  In the light emitting device including a plurality of minute light emitting portions including an elongated opening and electrodes having a plurality of shapes having different aspect ratios, the inventor forms the shape of the opening and the electrodes and their long axes. A light-emitting device using an organic light-emitting element that can easily control the luminance gradient in the light-emitting surface by controlling the angle was found, and the present invention was completed. That is, the present invention is summarized below.

  According to the present invention, there is provided a light emitting device having a light emitting region composed of a plurality of light emitting portions having a minimum width of 0.1 μm to 10 μm that are electrically connected in parallel, and the light emitting region is a single planar conductor. An insulating layer formed on the upper surface of the planar conductor, a plurality of openings formed in the insulating layer, a plurality of first electrodes formed on the insulating layer, and a plurality of the first electrodes An organic compound layer including a light-emitting layer formed over one electrode, and a second electrode formed on the organic compound layer, wherein at least some of the plurality of first electrodes are in the opening. The electrodes are formed to be electrically connected to the conductor to form an electrode for energizing the organic compound layer in the plurality of light emitting portions, and the plurality of openings are first orthogonal to each other in plan view. Having an elongated shape having a major axis and a first minor axis within the light emitting region The first long axes are formed so as to be parallel to each other, and the plurality of first electrodes include two types of electrodes having different shapes, and one of the second long axes and the second are orthogonal to each other in plan view. The first electrode A has an elongated shape having a short axis, and the other is a first electrode B having a shape having a third long axis and a third short axis that are orthogonal to each other in plan view. The plurality of first electrodes A having a long axis are formed such that the second long axes are parallel to each other in the light emitting region, and the plurality of first electrodes B having the third long axis are The third major axis is formed in parallel to each other in the light emitting region, and the distance between the openings in the first minor axis direction of the openings is the first of the first electrodes A. Longer than the length of the minor axis of 2, and shorter than the length of the third minor axis of the first electrode B. Optical apparatus is provided.

The first long axis of the opening is at least five times longer than the first short axis, and the second long axis of the first electrode A is at least five times longer than the second short axis. Preferably, the third major axis of the first electrode B is 1 to 2 times as long as the third minor axis.
It is preferable that an angle (θ) between the first long axis of the opening and the second long axis of the first electrode A is 0 to 80 degrees.
In the light emitting region, it is preferable that the first electrode A electrically connected to the conductor and the first electrode A not connected to the conductor are mixed.
The distance between the openings in the first minor axis direction of the openings is preferably shorter than the length of the second major axis of the first electrode A.
The length of the first short axis of the opening, the length of the second short axis of the first electrode A, and the length of the third short axis of the first electrode B are respectively 0. It is preferable that the number of the openings and the first electrode is 10 ² to 10 ⁸ in an arbitrary 1 mm square region of the light emitting region.
In an arbitrary 1 mm square region in the light emitting region in plan view, the area ratio occupied by the first electrode is preferably 50% or more.
Preferably, the openings are formed in the light emitting region so that the first long axes face each other in parallel and periodically.
The conductor is a transparent conductive film made of a metal oxide, and is formed on at least a part of the outside of the light emitting region, and has a terminal portion that is electrically connected to the conductor and connected to a power source. In the light emitting region, the ratio of the number of the first electrodes B to the total number of the first electrodes is larger in a region farther from the terminal portion, and the first major axis and the second length are increased. The angle formed by the axes is preferably constant within the light emitting region.

Next, according to the present invention, there is provided a method for reducing the luminance distribution of a light emitting device, wherein the first light emitting device is manufactured using a method for manufacturing a light emitting device comprising the following steps (1) to (5). Manufacture and
(1) A step of preparing one planar conductor,
(2) forming an insulating layer having a plurality of openings on the upper surface of the planar conductor;
(3) forming a plurality of first electrodes on the insulating layer so that an angle formed by the first major axis and the second major axis is a constant angle θ ₁ ;
(4) forming an organic compound layer including a light emitting layer so as to cover the plurality of first electrodes;
(5) forming a second electrode on the organic compound layer;
When the luminance distribution of the first light emitting device is measured and the luminance distribution is not within a predetermined range, in the method of manufacturing the light emitting device, the first long axis and the first A method of reducing the luminance distribution of the light emitting device is provided, wherein the second light emitting device is manufactured by setting the angle formed by the major axis of 2 to a constant angle θ ₂ different from θ ₁ .

  ADVANTAGE OF THE INVENTION According to this invention, the luminance gradient in the light emission surface of an organic light emitting element is controlled easily, and the light-emitting device using such an organic light emitting element is provided.

It is a fragmentary sectional view of the light emission part vicinity of the light-emitting device to which this Embodiment is applied. It is a figure explaining an example of a shape and relative arrangement of an opening and the 1st electrode A in a light emitting device to which this embodiment is applied. It is a figure explaining the example of the planar shape of the 1st electrode A and an opening part. In the light-emitting device to which this Embodiment is applied, it is a figure explaining an example of the shape of a opening part and the 1st electrode B, and relative arrangement | positioning. It is a figure explaining an example from which the ratio of the 1st electrode A and the 1st electrode B changes with the distance from a terminal part in the light emission area | region in the light-emitting device to which this Embodiment is applied.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary. That is, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. . The drawings used are examples for explaining the present embodiment and do not represent actual sizes. The size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Further, in this specification, “on” such as “on the layer” is not necessarily limited to the case where it is formed in contact with the upper surface, and is formed on the upper side in a separated manner or between layers. It is used in a sense that includes an intervening layer.

(Light emitting device)
The light-emitting device to which this embodiment is applied has a plurality of light-emitting portions with a minimum width of 0.1 μm to 10 μm that are electrically connected in parallel, and a light-emitting region that includes all of these light-emitting portions. Have. The light emitting device may have only one light emitting region or two or more light emitting regions. Each light emitting region has one planar conductor. Each light emitting region is formed on an upper surface of a planar conductor, and includes an insulating layer having a plurality of openings, a plurality of first electrodes formed on the insulating layer, and the plurality of first electrodes. An organic compound layer including a light-emitting layer and a second electrode formed on the organic compound layer are formed. Each light emitting area is divided into a plurality of sections, and each section includes two or more of the first electrodes. The plurality of sections may be the same or different in area and shape.

(Light Emitting Unit 10)
FIG. 1 is a partial cross-sectional view in the vicinity of one light emitting unit 10 among a plurality of light emitting units of a light emitting device to which the present embodiment is applied.
As shown in FIG. 1A, a light emitting unit 10 of a light emitting device includes a planar conductor 12, an insulating layer 13, a first electrode 14, an organic compound layer 15 including a light emitting layer, and a second electrode on a substrate 11. 16 are stacked. An opening 17 is provided in the insulating layer 13, and the first electrode 14 is electrically connected to the conductor 12 at a part inside the opening 17. When the first electrode 14 and the conductor 12 are electrically connected inside the opening 17, the portion of the organic compound layer 15 in contact with the first electrode 14 emits light.
Further, as shown in FIG. 1B, the first electrode 14 may be electrically connected to the conductor 12 throughout the opening 17.

(Substrate 11)
The substrate 11 serves as a support for forming the conductor 12, the insulating layer 13, the first electrode 14, the organic compound layer 15, and the second electrode 16. A material that satisfies the mechanical strength required for the light emitting device including the light emitting unit 10 is used for the substrate 11.
As a material used for the substrate 11, when it is desired to extract light emitted from the light emitting layer from the substrate 11 side, it is necessary to have transparency to this light. Specifically, glass such as sapphire glass, soda glass, and quartz glass; transparent resin such as polymethyl methacrylate resin, polycarbonate resin, polyester resin, and silicone resin; transparent metal nitride such as aluminum nitride; transparent metal such as alumina An oxide etc. are mentioned. In addition, when using the resin film which consists of the said transparent resin as the board | substrate 11, it is preferable that gas permeability with respect to gas, such as water and oxygen, is low, and in the range which does not impair light permeability largely, it is a transparent resin film. It is preferable to form a gas barrier thin film that suppresses gas permeation.

When it is not necessary to extract light emitted from the light emitting layer from the substrate 11 side, the material of the substrate 11 is not limited to the transparent material described above, and an opaque material can also be used. Specifically, such materials include silicon (Si), copper (Cu), silver (Ag), gold (Au), platinum (Pt), tungsten (W), titanium (Ti), tantalum (Ta), Alternatively, niobium (Nb) alone, an alloy containing these, stainless steel, or the like can be given. As the material of the opaque substrate 11, a metal material having high light reflectivity is preferable in order to extract more light emitted from the light emitting layer to the outside. Moreover, you may use what formed the light reflection film which consists of a light-reflective metal material on the surface of said light-transmitting material.
The thickness of the substrate 11 is appropriately selected depending on the required mechanical strength and is not particularly limited. However, in the present embodiment, it is preferably 0.1 mm to 10 mm, more preferably 0.25 mm to 2 mm.

(Conductor 12)
The conductor 12 is formed in a planar shape continuous over the entire light emitting region on the substrate 11 and supplies power to the first electrode 14 in the light emitting region. The material used for the conductor 12 is not particularly limited as long as it has electrical conductivity. When it is desired to extract light emitted from the light emitting layer from the substrate 11 side, the material forming the conductor 12 needs to be transmissive to this light. As such a material, a metal oxide is preferable. Specific examples include indium tin oxide (ITO), indium zinc oxide (IZO), and tin oxide. The thickness of the conductor 12 can be formed in the range of 2 nm to 2 μm, for example. However, 50 nm or more is preferable from the viewpoint of high conductivity, and 500 nm or less is preferable in that high light transmittance is maintained.

  In the case where it is not necessary to extract light emitted from the light emitting layer from the substrate 11 side, as the material of the conductor 12, the metal materials mentioned as the opaque materials usable for the substrate 11 can be used. Further, the conductor 12 can also serve as the substrate 11. Therefore, the thickness of the conductor 12 made of a metal material is preferably 2 nm to 10 mm, and more preferably 50 nm to 2 mm.

(Insulating layer 13)
The insulating layer 13 is laminated on the conductor 12 and separates and insulates the conductor 12 and the first electrode 14 at locations other than the opening 17. For this reason, the insulating layer 13 is preferably a material having a high resistivity. Specifically, the resistivity is preferably 10 ⁸ Ω · cm or more, and more preferably 10 ¹² Ω · cm or more. Specific examples of the material for the insulating layer 13 include metal nitrides such as silicon nitride, boron nitride, and aluminum nitride; and metal oxides such as silicon oxide and aluminum oxide. Furthermore, polymer compounds such as polyimide, polyvinylidene fluoride, and parylene, spin-on glass (SOG), and the like can also be used.

  The thickness of the insulating layer 13 preferably does not exceed 5 μm so that the electrical resistance between the conductor 12 and the first electrode 14 does not become too large. However, if it is too thin, the dielectric strength may not be sufficient. Accordingly, the film is preferably formed to have a thickness of 10 nm to 5 μm, more preferably 50 nm to 500 nm.

  In addition, when the insulating layer 13 extracts light from the surface on the substrate 11 side, the light extracted from the substrate 11 can be increased by refracting light incident from the organic compound layer 15 and changing the traveling direction of the light. it can. For this purpose, as the material of the insulating layer 13, a material having a high transmittance for emitted light and having a higher refractive index or a lower refractive index than the organic compound layer is used. The absolute value of the difference from the refractive index is preferably larger than 0.1.

(Opening 17)
The opening 17 is formed through the insulating layer 13. In addition, at least a part of the plurality of first electrodes 14 formed on the insulating layer 13 is electrically connected to the conductor 12 inside the opening 17, whereby the first electrode 14 is formed from the conductor 12. Is supplied with power.
The opening 17 may be formed so as to penetrate through the conductor 12, and in this case, the bottom of the opening 17 is the top surface of the substrate 11, and the first electrode 14 is connected to the side surface of the conductor 12 inside the opening 17. Electrically connected. When a voltage is applied between the first electrode 14 and the second electrode 16, a current flows between the electrodes, and the light emitter included in the light emitting layer of the organic compound layer 15 emits light. Therefore, at this time, the region on the first electrode 14 in a plan view is a light emitting portion.

(First electrode 14)
In the present embodiment, a plurality of first electrodes 14 exist in one light emitting region. The first electrode 14 is an electrode in which at least a part of the first electrode 14 is also formed in the opening 17 and is electrically connected to the conductor 12, thereby energizing the organic compound layer 15 in a plurality of light emitting portions. Function as. In the present embodiment, the first electrode 14 is an anode. The first electrode 14 is electrically connected to the conductor 12 inside the opening 17, and injects holes into the organic compound layer 15 by applying a voltage between the second electrode 16.

  The material used for the first electrode 14 is preferably a material having high electrical conductivity and a work function of 4.5 eV or more. Examples of such materials include conductive metal oxides such as ITO, IZO, and tin oxide, metals, and the like. Moreover, you may use the electroconductive material which consists of organic substances, such as a polyaniline derivative, a polythiophene derivative, and the mixture of these polymers, and a polystyrene sulfonic acid. Among these, ITO, IZO, and poly (3,4-ethylenedioxythiophene) -polystyrene sulfonic acid mixture (PEDOT: PSS) that can easily inject holes into the organic compound layer 15 are preferable.

  As described above, in order to improve the light extraction efficiency, when the emitted light is incident on the side surface of the opening 17 of the insulating layer 13 and the light is extracted, the first electrode 14 transmits the emitted light. It is necessary to use materials with a high rate. In this respect, among the above materials, a conductive material made of a conductive metal oxide or an organic material is preferable.

The first electrode 14 can be formed with a thickness of 2 nm to 2 μm, for example. However, 50 nm or more is preferable from the viewpoint of high conductivity, and 500 nm or less is preferable from the viewpoint of easy patterning of the first electrode 14 and formation of the organic compound layer 15. The work function can be measured by a method such as ultraviolet photoelectron spectroscopy.
In the present embodiment, the plurality of first electrodes include at least two types of first electrodes having different planar shapes, that is, a first electrode A and a first electrode B. Specifically, the first electrode A and the first electrode B are different in the ratio of the length of the major axis and the length of the minor axis of the planar shape, and the first electrode A is longer than the first electrode B. The ratio of length / minor axis length is large, and the shape is elongated.

(Organic compound layer 15)
The organic compound layer 15 includes a light emitting layer, and includes a single layer or a layer including a plurality of stacked organic compounds. In the present embodiment, the organic compound layer 15 covers the first electrode 14 and is formed as a continuous film on the entire surface of the light emitting region. Is done. The light emitting layer includes a light emitting material that emits light when a voltage is applied between the first electrode 14 and the second electrode 16. As such a light emitting material, a known light emitting material can be used, and any of a light emitting polymer compound and a light emitting non-polymer compound can be used. In this embodiment mode, it is preferable to use a phosphorescent organic compound or a metal complex which is a light-emitting organic material as the light-emitting material.

  Furthermore, in the present embodiment, it is very desirable to use a cyclometalated complex as the light emitting material from the viewpoint of improving the light emission efficiency. Examples of cyclometalated complexes include 2-phenylpyridine derivatives, 7,8-benzoquinoline derivatives, 2- (2-thienyl) pyridine derivatives, 2- (1-naphthyl) pyridine derivatives, 2-phenylquinoline derivatives, and the like. Examples of the complex include iridium (Ir) having a ligand; platinum (Pt) and gold (Au). Among these, an Ir complex is particularly preferable. The cyclometalated complex may have other ligands in addition to the ligands necessary for forming the cyclometalated complex. The cyclometalated complex includes a compound that emits light from triplet excitons, and such a compound is preferable from the viewpoint of improving luminous efficiency.

  Moreover, as a light emitting polymer compound, poly-p-phenylene vinylene (PPV) derivatives, such as (poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene vinylene]) (MEH-PPV) Π-conjugated polymer compounds such as polyfluorene derivatives and polythiophene derivatives; non-conjugated polymers in which a dye molecule and a tetraphenyldiamine derivative or a triphenylamine derivative are introduced into the main chain or side chain. A light emitting polymer compound and a light emitting non-polymer compound may be used in combination.

  The light emitting layer includes a host material together with the light emitting material, and the light emitting material may be dispersed in the host material. Such a host material preferably has a charge transporting property, and is preferably a hole transporting compound or an electron transporting compound.

The organic compound layer 15 may include a hole transport layer (not shown) for receiving holes from the first electrode 14 and transporting them to the light emitting layer. The hole transport layer is provided between the first electrode 14 and the light emitting layer.
As a hole transport material for forming such a hole transport layer, a known material can be used. For example, N, N′-diphenyl-N, N′-di (3-methylphenyl) -1,1′-biphenyl-4,4′diamine (TPD), 4,4′-bis [N- (1- Naphthyl) -N-phenylamino] biphenyl (α-NPD), 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA) and the like; polyvinylcarbazole A polymer compound obtained by polymerizing the above triphenylamine derivative by introducing a polymerizable substituent. The above hole transport materials may be used singly or in combination of two or more, and a plurality of hole transport layers formed from different hole transport materials may be laminated.

  In addition, a hole injection layer (not shown) for relaxing the hole injection barrier may be provided between the hole transport layer and the first electrode 14. Examples of the material for forming the hole injection layer include known materials such as copper phthalocyanine, fluorocarbon, and silicon dioxide. Further, a mixture of a hole transport material used for the hole transport layer and an electron acceptor such as 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinonedimethane (F4TCNQ) may be used. it can. When the 1st electrode 14 is formed from materials other than electroconductive polymers, such as ITO and IZO, in addition to said material, electroconductive polymers, such as PEDOT: PSS, can also be used as a hole injection layer.

  The organic compound layer 15 includes an electron transport layer (not shown) for receiving electrons from the second electrode 16 serving as a cathode and transporting the electrons to the light emitting layer, between the light emitting layer and the second electrode 16. Also good. Examples of materials that can be used for such an electron transport layer include aluminum complexes, zinc complexes, quinoline derivatives, oxadiazole derivatives, perylene derivatives, pyridine derivatives, pyrimidine derivatives, triazine derivatives, quinoxaline derivatives, and triarylborane derivatives. And triphenylphosphine oxide derivatives. More specifically, tris (8-quinolinolato) aluminum (abbreviation: Alq), bis [2- (2-hydroxyphenyl) benzoxazolate] zinc, bis [2- (2-hydroxyphenyl) benzothiazolate] zinc 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole and the like.

  In addition, for the purpose of suppressing the passage of holes through the light emitting layer between the electron transport layer and the light emitting layer and efficiently recombining holes and electrons in the light emitting layer, a hole blocking layer ( (Not shown) may be provided. This hole blocking layer can also be regarded as one of the layers included in the organic compound layer 15. In order to form the hole blocking layer, a known material such as a triazole derivative, an oxadiazole derivative, or a phenanthroline derivative can be used.

The thickness of each of the layers constituting the organic compound layer 15 is appropriately selected in consideration of charge mobility, charge injection balance, interference of emitted light, and the like, and is not particularly limited. In the present embodiment, the thickness is preferably 1 nm to 1 μm, more preferably 2 nm to 500 nm, and particularly preferably 5 nm to 200 nm. The thickness of the organic compound layer 15 obtained by adding the thicknesses of the layers between the first electrode 14 and the second electrode 16 is preferably 30 nm to 1 μm, more preferably 50 nm to 500 nm.
Note that by controlling the thickness of the organic compound layer 15, a microresonator structure can be formed, and the spectrum and intensity of light extracted outside the light emitting device can be changed. In this case, one of the first electrode 14 and the second electrode 16 is a semi-reflective electrode (not shown) made of a metal thin film or the like having a thickness of 5 nm to 50 nm, and is reflected as the other electrode. An electrode (not shown) is used.

(Second electrode 16)
The second electrode 16 applies a voltage between the first electrode 14 and injects electrons into the organic compound layer 15. That is, in the present embodiment, the second electrode 16 is a cathode. The second electrode 16 is formed as a continuous film on the entire surface of the light emitting region on the organic compound layer 15. The material used for the second electrode 16 is not particularly limited as long as it has electrical conductivity. In the present embodiment, a material having a low work function and being chemically stable is preferable. Specifically, materials such as aluminum (Al), magnesium-silver (MgAg) alloys, alloys of Al and alkaline earth metals (or alkali metals) such as aluminum-lithium (AlLi) and aluminum-calcium (AlCa) Is mentioned. However, the material of the second electrode 16 is preferably a material transparent to visible light, for example, similar to the first electrode 14 when it is desired to extract light emitted from the light emitting layer from the second electrode 16 side.
The thickness of the second electrode 16 is preferably 10 nm to 1 μm, and more preferably 50 nm to 500 nm.

  Further, a cathode buffer layer (not shown) is provided adjacent to the second electrode 16 for the purpose of lowering the electron injection barrier from the second electrode 16 to the organic compound layer 15 and increasing the electron injection efficiency. It may be provided on the 15 side. Examples of the cathode buffer layer include alkali metals (Na, K, Rb, Cs), magnesium (Mg), alkaline earth metals (Sr, Ba, Ca), rare earth metals (Pr, Sm, Eu, Yb), or A material selected from fluorides, chlorides and oxides of these metals or a mixture of two or more thereof can be used. The thickness of the cathode buffer layer is preferably from 0.1 nm to 50 nm, more preferably from 0.1 nm to 20 nm, and even more preferably from 0.5 nm to 10 nm.

  In the present embodiment, in the light emitting unit 10 of the light emitting device shown in FIG. 1, the first electrode 14 formed in contact with the conductor 12 is an anode, and the second electrode 16 formed on the organic compound layer 15 is Although it is a cathode, an anode and a cathode may be reversed. That is, the first electrode 14 may be a cathode and the second electrode 16 may be an anode.

In order to form the conductor 12, the insulating layer 13, the first electrode 14, the organic compound layer 15 and the second electrode 16 formed on the substrate, resistance heating vapor deposition, electron beam vapor deposition, sputtering, ion A plating method, a CVD method, or the like can be used.
In addition, when a coating film forming method (that is, a method in which a target material is dissolved in a solvent and applied to the substrate 11 and drying) is possible, a spin coating method, a dip coating method, an ink jet method, a printing method, It is also possible to form a film using a method such as a spray method or a dispenser method. Among these, it is preferable to use the resistance heating vapor deposition method and the coating film forming method for forming the organic compound layer 15.

(Relative arrangement of the opening and the first electrode A)
FIG. 2 is a diagram for explaining an example of the shape of the opening 17 of the insulating layer 13 and the first electrode A (14A) and their relative arrangement in the light emitting device to which the present embodiment is applied.
In FIG. 2, each shape of the plurality of openings 17 and the plurality of first electrodes A (14 </ b> A) formed in the insulating layer 13 in one section in the light emitting region of the light emitting device to which the present embodiment is applied. Each relative arrangement is shown in plan view.

FIG. 2A shows a plurality of openings 17 having a rectangular planar shape and a plurality of first electrodes A (14 </ b> A) having a rectangular planar shape, in one section in the light emitting region. An example in which the long axes are arranged so as to be substantially parallel to each other is shown.
In FIG. 2A, the planar shapes of the plurality of openings 17 are substantially the same. Each of the plurality of openings 17 has an elongated rectangular shape having a first major axis and a first minor axis that are orthogonal to each other, the first major axes are arranged in parallel to face each other, and the first Are arranged at regular intervals in the minor axis direction (FIG. 2A shows two of the plurality of openings). Here, the first long axis of the opening 17 indicates the long side of the rectangle, and the first short axis indicates the short side of the rectangle.

In the present embodiment, it is preferable that the length of the first major axis of the opening 17 is three times or more the length of the first minor axis. Further, it is more preferably 5 times or more the length of the first short axis.
Note that the lengths of the first major axis and the first minor axis in the elongated shape are not strictly defined for every shape, but are, for example, the maximum width of the shape in each axial direction. Is defined.
Further, the most preferable case of the opening 17 is when the length of the long axis = the length of the light emitting surface. That is, one opening 17 is not divided in the major axis direction. When the area of the opening 17 is large, the contact area between the light emitting layer and the first electrode A (14A) increases, and the light emitting area increases.

In FIG. 2A, the planar shapes of the plurality of first electrodes A (14A) are substantially the same. Each of the plurality of first electrodes A (14A) has an elongated rectangular shape having a second major axis and a second minor axis that are orthogonal to each other, and the second major axes are arranged parallel to each other. However, they are formed so as to be arranged periodically at regular intervals in the vertical and horizontal directions. Here, the second long axis of the first electrode A (14A) indicates the long side of the rectangle, and the second short axis indicates the short side of the rectangle.
In the present embodiment, the length of the second major axis of the first electrode A (14A) is preferably not less than five times the length of the second minor axis. However, normally, the length of the second major axis is 20 times or less the length of the second minor axis. The distance between the openings 17 in the first minor axis direction of the openings 17 is longer than the length of the second minor axis of the first electrode A (14A).

  In FIG. 2 (a), the plurality of first electrodes A (14A) are periodically arranged. However, the present embodiment is not limited to this, and the first electrodes A (14A) are randomly arranged within the above range. Also good. However, when one section is viewed macroscopically, the plurality of first electrodes A (14A) need to be distributed with a substantially uniform density. The plurality of first electrodes A (14A) are preferably arranged so that the area where the electrodes are formed is larger than the light emitting area.

As described with reference to FIG. 1, the first electrode A (14 </ b> A) and the conductor 12 are electrically connected inside the opening 17, whereby a voltage is applied to the first electrode A (14 </ b> A) and the second electrode 16. When applied, the portion of the organic compound layer 15 in contact with the first electrode A (14A) emits light.
Here, in FIG. 2A, an example in which the opening 17 having a rectangular planar shape and the first electrode A (14A) having a rectangular planar shape are arranged substantially parallel to each other. Is shown. In this case, since the distance between the opening portions 17 is longer than the length of the second short axis of the first electrode A (14A), the first electrode A that does not come into contact with the conductor 12 in the opening portion 17 (electrically isolated). The number of (14A) increases. In other words, the first electrode 14A electrically connected to the conductor 12 in the opening 17 and the first electrode A (14A) not electrically connected to the conductor 12 are mixed. Of the 20 first electrodes A (14A) in FIG. 2A, the number of the first electrodes A (14A) that are also formed in the opening 17 and are in contact with the conductive layer 12 is eight. Since the portion where the first electrode A (14A) exists becomes the light emitting portion 10, there are eight light emitting portions 10. Moreover, since the light emitting layer included in the organic compound layer 15 on the first electrode A (14A) that is not electrically connected to the conductor 12 does not emit light, the light emission luminance is lowered as a whole.

  On the other hand, in FIG. 2B, the planar shapes and arrangements of the plurality of openings 17 and the plurality of first electrodes A (14A) are the same as those in FIG. 2A is different from FIG. 2A in that the angle (θ) between the first long axis and the second long axis of the plurality of first electrodes A (14A) is 80 degrees. . In the present specification, the angle formed by the first major axis and the second major axis is represented by the angle on the acute side of the angles at which the two straight lines intersect. In this case, many first electrodes A (14 </ b> A) are in contact with the conductor 12 at any opening 17. In FIG. 2B, all of the first electrodes A (14A) are also formed inside the opening 17 and are in contact with the conductive layer 12. That is, there are 20 light emitting portions 10 included in FIG. It is. For this reason, the light emitting layer included in the organic compound layer 15 on all the first electrodes A (14A) emits light, and the light emission luminance is increased as a whole.

  As described above, the total area of the light emitting units 10 in the region of FIG. 2A is smaller than the total area of the light emitting units 10 in the region of FIG. The average luminance in the area 2 (a) is lower than that in the area 2b.

  As described above, in the present embodiment, the arrangement of the plurality of openings 17 having an elongated shape and the plurality of first electrodes A (14A) having an elongated shape in the same section is changed. Thus, it is possible to control the light emission luminance of the light emitting region in the section. Specifically, by changing the angle (θ) formed by the first major axis of the opening 17 and the second major axis of the first electrode A (14A) within a range of 0 degrees to 90 degrees, The luminance of an arbitrary area in the light emitting area can be greatly changed.

  As described above, in the present embodiment, the length of the first major axis of the opening 17 and the length of the second major axis of the first electrode A (14A) are set to the first short axis of the opening 17, respectively. By setting the length of the shaft and the length of the second short axis of the first electrode A (14A) to be five times or more, the first long axis of the opening 17 and the second long axis of the first electrode A (14A) The brightness can be easily controlled by changing the angle (θ) formed by.

(Planar shape of first electrode A and opening)
Here, the planar shape of the first electrode A (14A) and the opening 17 is not limited to the rectangle as shown in FIGS. 2A and 2B, but is preferably an elongated shape. Next, an example of the planar shape of the first electrode A (14A) and the opening 17 will be described.

FIG. 3 is a diagram for explaining an example of the planar shape of the first electrode A (14 </ b> A) and the opening 17.
As described above, the planar shape of the first electrode A (14A) and the opening 17 is not limited to a rectangle, but is preferably an elongated shape. Examples of the elongated shape including a rectangle include, for example, a rectangle (FIG. 3A), an ellipse (FIG. 3B), a rhombus (FIG. 3C), and a parallelogram (FIG. 3D). , Triangles (FIGS. 3E and 3F), trapezoids (FIGS. 3G and 3H), and the like.
When the first electrode A (14A) and the opening 17 have such an elongated shape, the directions of the first major axis of the opening 17 and the second major axis of the first electrode 14 are in any shape. Although not strictly defined, it is only necessary to be along the longitudinal direction of each shape. For example, the shapes shown in FIGS. 3A to 3H are defined as follows.

For elongated rectangular as shown in FIG. 3 (a), the first major axis x _a a first short axis y _a of the opening 17 are each long side and short side, a first long axis x _a length and the length of the first short axis y _a of is defined as the length of the long and short side of each long side.
Similarly, the second major axis x _a and the second short axis y _a of the first electrode A (14A) are each long side and short side, the second major axis x _a length and a second the length of the minor axis y _a is defined as the length of the long and short side of each long side.

For oval shown in FIG. 3 (b), the first major axis x _b and the first short axis y _b of the opening 17, respectively coincide with the major and minor axes of the ellipse, the first length the length of the axis x _b of the length of the first short axis y _b are defined respectively major axis and a minor axis.
Similarly, the second major axis x _b and the second short axis y _b of the first electrode A (14A), respectively match the major and minor axes of the ellipse, the length of the second major axis x _b the length of the second short axis y _b are defined respectively major axis and a minor axis.

In the case of the elongated rhombus shown in FIG. 3C, the first major axis x _c of the opening 17 is a line segment connecting two apexes of acute angles, and the first minor axis y _c is two obtuse angles. Is defined as the line connecting the vertices.
Similarly, the second major axis x _c of the first electrode A (14A) is a line segment connecting the two acute vertices of the second short axis y _c is the line segment connecting two obtuse apex of the Is defined as

For elongated parallelogram shown in FIG. 3 (d), the first major axis x _d of the opening 17 is long side direction of the first short axis y _d in the first major axis x _d a direction orthogonal, its length is defined as the width of the parallelogram in the direction of the first short axis y _d.
Similarly, the second major axis x _d of the first electrode A (14A) is a long side, the direction of the second short axis y _d is a direction perpendicular to the second major axis x _d, the length it is is defined as the width of the parallelogram in the direction of the second short axis y _d.

In the case of an elongated isosceles triangle having a short base shown in FIG. 3E, the first major axis x _e of the opening 17 is a line segment connecting the vertex and the midpoint of the base, and the first minor axis y _e is defined to be the base.
Similarly, the second major axis x _e of the first electrode A (14A) is a line segment connecting the midpoint of the vertex and the base, the second short axis y _e is defined to be the base.

If the apex angle as shown in FIG. 3 (f) is obtuse elongated isosceles triangle, the first long axis x _f of the opening 17 is the bottom, the midpoint of the first short axis y _f vertex and base Is defined as a line segment connecting
Similarly, the second major axis x _f of the first electrode A (14A) is base, is defined as the second short axis y _f a line segment connecting the midpoint of the vertices and bottom.

In the case of an elongated trapezoid whose upper and lower bases are short as shown in FIG. 3 (g), the first major axis _xg of the opening 17 is the vertical line of the upper base (lower base). The first short axis y _g is defined as the longer side of the upper base and the lower base.
Similarly, the second major axis _xg of the first electrode A (14A) is a line segment existing between the upper base and the lower base among the vertical lines of the upper base (lower base), and the second short axis _xg The axis y _g is defined as the longer side of the upper and lower bases.

Figure 3 (h) in the upper base and if lower base of long slender trapezoid shown, the first long axis x _h of the opening 17 is a longer side ones of the upper base and lower base, the first minor axis y _h of, among the perpendicular of the upper base (lower base) is defined as a line segment that exists between the upper base and the lower base.
Similarly, the second major axis x _h of the first electrode A (14A) is a side of the longer of the upper base and lower base, the second short axis y _h is the upper base (lower base) Is defined as a line segment existing between the upper base and the lower base.

  The lengths of the first major axis (or second major axis) and the first minor axis (or second minor axis) in the elongated shape other than the shape shown in FIG. Although not strictly defined, for example, it is defined as the maximum width of the shape in each axial direction.

(Relative arrangement of the opening and the first electrode B)
FIG. 4 is a diagram for explaining an example of the shape of the opening 17 and the first electrode B (14B) of the insulating layer 13 and their relative arrangement in the light emitting device to which the present embodiment is applied.
FIG. 4 shows a plurality of openings 17 formed in the insulating layer 13 and the first electrode A (14A) described above in one section in the light emitting region of the light emitting device to which the present embodiment is applied. Each shape of the plurality of first electrodes B (14B) having different major axis / minor axis ratios and their relative arrangement are shown in plan view. Here, the value of the major axis / minor axis ratio of the first electrode B (14B) is smaller than the first electrode A (14A) and closer to 1.

FIG. 4A shows that a plurality of rectangular openings 17 and a first electrode B (14B) having a rectangular planar shape are substantially parallel to each other in one section within the light emitting region. An example of the arrangement is shown.
In FIG. 4A, the planar shape of the plurality of openings 17 is substantially the same as in FIG. 2 described above. Each of the plurality of openings 17 has an elongated rectangular shape having a first major axis and a first minor axis that are orthogonal to each other. The first major axes are arranged in parallel so as to face each other, and vertically and horizontally. They are arranged periodically at regular intervals (FIG. 4 (a) shows two of the plurality of openings). Here, the first long axis of the opening 17 indicates the long side of the rectangle, and the first short axis indicates the short side of the rectangle.

  In FIG. 4A, the plurality of first electrodes B (14B) are periodically arranged. However, the present embodiment is not limited to this, and the first electrodes B (14B) are randomly arranged within the above range. Also good. However, when one section is viewed macroscopically, the plurality of first electrodes B (14B) need to be distributed with a substantially uniform density. The plurality of first electrodes B (14B) are preferably arranged such that the area where the electrodes are formed is larger than the light emitting area.

In the present embodiment, it is preferable that the length of the first major axis of the opening 17 is three times or more the length of the first minor axis. Further, it is more preferably 5 times or more the length of the first short axis.
Note that the lengths of the first major axis and the first minor axis in the elongated shape are not strictly defined for every shape, but are, for example, the maximum width of the shape in each axial direction. Is defined.
Further, the most preferable case of the opening 17 is when the length of the long axis = the length of the light emitting surface. That is, one opening 17 is not divided in the major axis direction. If the area of the opening 17 is large, the contact area between the light emitting layer and the first electrode B (14B) increases, and the light emitting area increases.

  In FIG. 4A, the planar shapes of the plurality of first electrodes B (14B) are substantially the same. Each of the plurality of first electrodes B (14B) has a rectangular shape having a third major axis and a third minor axis orthogonal to each other, and is arranged periodically at regular intervals in the vertical and horizontal directions. Is formed. Here, the third long axis of the first electrode B (14B) indicates the long side of the rectangle, and the third short axis indicates the short side of the rectangle.

In the present embodiment, the length of the third major axis of the first electrode B (14B) is preferably in the range of 1 to 2 times the length of the third minor axis. Further, the length of the third major axis may be equal to the length of the third minor axis (for example, a square). In the light emitting region, the direction of the third major axis of the first electrode B (14B) may be the same as or different from the direction of the second major axis of the first electrode A (14A). .
That is, the first electrode B (14B) is different from the planar shape of the first electrode A (14A) (the length of the second major axis is not less than five times the length of the second minor axis). It has a long axis / short axis ratio value.
The distance between the openings 17 in the first minor axis direction of the openings 17 is shorter than the length of the third minor axis of the first electrode B (14B).

As described above, the first electrode B (14B) and the conductor 12 (see FIG. 1) are electrically connected inside the opening 17, whereby the first electrode B (14B) and the second electrode 16 are connected to each other. When a voltage is applied, the portion of the organic compound layer 15 that is in contact with the first electrode B (14B) emits light.
Here, as shown in FIG. 4A, the distance between the openings 17 in the first minor axis direction of the openings 17 is shorter than the length of the third minor axis of the first electrode B (14B). All the first electrodes 14 </ b> B are in contact with the conductor 12 in any opening 17. Therefore, light emission occurs in the portion of the organic compound layer 15 that is in contact with all the first electrodes B (14 B), and all the portions where the first electrode B (14 B) exists are the light emitting portions 10.

On the other hand, in FIG. 4B, the planar shapes and arrangement of the plurality of openings 17 and the plurality of first electrodes B (14B) are the same as those in FIG. 4A is that the angle (θ ′) between the direction of the major axis of the first electrode B and the direction of the second major axis of the first electrode B (14B) is 80 degrees. Different.
Also in this case, the distance between the openings 17 in the first minor axis direction of the openings 17 is shorter than the length of the third minor axis of the first electrode B (14B) (of course, the first electrode B (14B) Therefore, all the first electrodes B (14B) are in contact with the conductor 12 in any one of the openings 17. Therefore, light emission occurs in the portion of the organic compound layer 15 that is in contact with all the first electrodes B (14 B), and all the portions where the first electrode B (14 B) exists are the light emitting portions 10.

  Thus, as shown in FIGS. 4A and 4B, the distance between the openings 17 in the first short axis direction is shorter than the length of the third short axis of the first electrode B (14B). In this case, even if the angle (θ ′) between the direction of the first major axis in the opening 17 and the direction of the third major axis in the first electrode B (14B) changes, the number of light emitting units 10 is It does not change and the light emission luminance does not change. 4A shows the case where θ ′ is 0 degree and FIG. 4B shows the case where θ ′ is 80 degrees. However, θ ′ is in the range of 0 degree to 90 degrees, that is, what angle is θ ′. However, the number of the light emitting units 10 does not change, and the light emission luminance does not change.

  As described above, the first electrode 14 (see FIG. 1) in the light emitting region of the light emitting device to which the present embodiment is applied is the first electrode A (14A) having an elongated shape (that is, the first electrode A (14A). ) Of the second major axis is not less than five times the length of the second minor axis) and the first electrode A (14A) is the length of the major axis / the length of the minor axis. Two types of first electrodes B (14B) having different ratios (that is, the length of the third major axis of the first electrode B (14B) is 1 to 2 times the length of the third minor axis). Contains. Here, the ratio in which the first electrode A (14A) and the first electrode B (14B) are included is not limited. Further, the first electrode A (14A) preferably has at least one region in which the second long axes are arranged in parallel to face each other and are arranged periodically at regular intervals in the vertical and horizontal directions. However, it is not necessarily limited to this. On the other hand, it is preferable that the first electrode B (14B) has at least one region in which the third major axes are arranged in parallel so as to face each other and are arranged periodically at regular intervals in the vertical and horizontal directions. However, it is not necessarily limited to this.

  And the direction of the 1st major axis of the opening part 17 is set with respect to the 1st electrode 14 containing the 1st electrode A and the 1st electrode B from which the ratio of the length of the major axis / the length of the minor axis differs. In the case of changing, if the ratio of the number of the first electrodes A (14A) having the second major axis to the total number of the first electrodes 14 in the light emitting region is large, the change in the light emission luminance becomes large. Conversely, when the ratio of the number of the first electrodes B (14B) having the third major axis is large, the change in the light emission luminance is small.

For example, the light emitting region is divided into a plurality of sections, and the pattern of the first electrode 14 is formed such that the number ratio of the first electrode A (14A) to the first electrode B (14B) is changed for each section. However, the in-plane orientation of the first electrode A (14A) is aligned in the entire region. In this case, the first electrode B can be obtained by changing the angle θ formed by the first major axis of the opening 17 (the pattern is uniform in the entire region) and the second major axis of the first electrode A (14A). It becomes possible to change the luminance ratio between sections having different number ratios of the first electrode A (14A) to (14B).
For example, when θ is 80 degrees, since the organic layer on almost all the first electrodes A (14A) emits light in the entire light emitting region, the luminance of any section in the light emitting region is substantially equal. On the other hand, when θ is decreased, the luminance is greatly reduced in the section where the ratio of the first electrode A (14A) is large, while the luminance remains high in the section where the ratio of the first electrode A (14A) is small.

Thus, by adjusting the ratio of the number of the first electrodes A (14A) and the first electrodes B (14B) having different ratios of the length of the major axis / the length of the minor axis, an arbitrary region of the light emitting region The light emission luminance of can be greatly changed.
Since the light emitting device to which the present embodiment is applied has the light emitting region in which the light emission luminance is controlled in this way, the first long axis in the opening 17 and the first electrode A (14A) in the first electrode A (14A). The angle (θ) formed with the major axis of 2 is preferably 0 to 80 degrees.

  The preferable size of the planar shape of the opening 17 and the first electrode 14 (first electrode A (14A), first electrode B (14B)) is visually recognized as a light emitting surface in which a plurality of light emitting units 10 are continuous, and emits light. It is determined from the viewpoint of easy manufacture of the device. In the present embodiment, the length of the first short axis in the opening 17, the length of the second short axis in the first electrode A (14A), and the length of the third short axis in the first electrode B (14B). The length is preferably in the range of 0.1 μm to 10 μm, respectively.

The opening 17 and the first electrode 14 (first electrode A (14A), the first electrode B (14B)) is in any 1mm square area of the light emitting region, respectively 10 ² to 10 ⁸ formed It is preferable that
Further, the length of the first short axis of the opening 17 is longer than the length of the second short axis of the first electrode A (14A) or the length of the third short axis of the first electrode B (14B). In the case of being long, the first electrode 14 (the first electrode A (14A) or the first electrode B (14B)) formed only in the opening 17 may be included. Even if it is such a 1st electrode 14, if it is in contact with the conductor 12, it will become an electrode of the light emission part 10. FIG.

In the present embodiment, it is easy to control the luminance by changing the angle (θ) formed by the first long axis of the opening 17 and the second long axis of the first electrode A (14A). Therefore, the distance between the openings 17 in the first short axis direction of the openings 17 is the length of the second major axis of the first electrode A (14A) and the third length of the first electrode B (14B). It is shorter than the length of the shaft and longer than the length of the second short shaft of the first electrode A (14A). Further, in order to always ensure the lowest luminance level in the luminance control by the first electrode B (14B), the distance between the openings 17 in the first minor axis direction of the openings 17 is the first electrode B ( 14B) is preferably shorter than the length of the third short axis.
Moreover, it is preferable that the ratio of the area which the 1st electrode 14 (1st electrode A (14A), 1st electrode B (14B)) occupies in the arbitrary 1 mm square area | regions in a light emission area | region is 50% or more.

Further, in the present embodiment, in the light emitting region, the plurality of openings 17 are formed so that the minor axis width is 0.1 μm to 10 μm, the major axes face each other in parallel and periodically. Also good. The interval formed periodically is preferably 0.1 μm to 100 μm. In this case, the opening 17 is preferably is 10 to 10 ⁴ formed in any 1mm square area of the light emitting region.

  In the light emitting device of this embodiment, a terminal portion for connecting to a power source is formed at least at a part outside the light emitting region. At this time, when the conductor 12 is a transparent conductive film made of a metal oxide such as ITO or IZO, the luminance decreases as the light emitting portion 10 in the light emitting region farther from the terminal portion due to a voltage drop due to the resistance of the conductor 12 itself. Tend to.

FIG. 5 is a diagram for explaining an example in which the ratio between the first electrode A and the first electrode B varies depending on the distance from the terminal portion in the light emitting region to which the present embodiment is applied.
In the present embodiment, the ratio of the first electrode B (14B) having the third major axis to the total number of the first electrodes 14 (first electrode A (14A), first electrode B (14B)) in the light emitting region. However, the 1st electrode 14 is formed so that it may become so large that the area | region far from the terminal part 18 is far. However, the arrangement of the first electrode A and the first electrode B shown in FIG. 5 is an example, and the present embodiment is not limited to this.

  In the case of FIG. 5, there are section 1, section 2, and section 3 from the side closer to the terminal portion 18, and the ratio of the first electrode B (14B) in these sections increases in this order. Here, in the light emitting region, all the in-plane orientations of the first major axis of the opening 17 are aligned, and the angle of the second major axis of the first electrode A (14A) with respect to the first major axis. θ takes the same value in the light emitting region. As a result, the ratio of the light emission area to the total area of the first electrode 14 can be increased as the region is farther from the terminal portion 18. Accordingly, it is possible to suppress the luminance unevenness due to the voltage drop caused by the darkness of the region far from the terminal portion 18 and the resistance of the conductor itself.

Further, by changing the angle formed by the first major axis of the opening 17 and the second major axis of the first electrode A (14A), the gradient of the luminance change in the light emitting region can be changed. Become.
For example, when θ is 80 degrees, since the organic layer on almost all the first electrodes A (14A) emits light in the entire light emitting region, the luminance of any section in the light emitting region is substantially equal. On the other hand, as θ is decreased, the luminance remains high in the section where the ratio of the first electrode A (14A) is small, whereas the decrease in luminance increases in the section where the ratio of the first electrode A (14A) is large. The gradient of brightness change also increases.

(Method for forming opening 17)
Examples of the method for forming the opening 17 include a method using photolithography. In order to perform this method, first, a resist solution is applied on the insulating layer 13, and the excess resist solution is removed by spin coating or the like to form a resist layer. Then, a mask on which a predetermined pattern for forming the opening 17 is drawn is applied, and exposure is performed using ultraviolet (UV), electron beam (EB), or the like.
Here, if the same-size exposure (for example, in the case of contact exposure or proximity exposure) is performed, a pattern of the opening 17 that is the same size as the mask pattern is formed. If reduced exposure (for example, exposure using a stepper) is performed, the pattern of the opening 17 reduced with respect to the mask pattern is formed. Next, when the exposed portion of the resist layer is removed using a developer, the resist layer in the pattern portion is removed.

  Next, the exposed portion of the insulating layer 13 (and the portion of the conductor 12 in some cases) is removed by etching to form an opening 17. As the etching, either dry etching or wet etching can be used. As dry etching, reactive ion etching (RIE) or inductively coupled plasma etching can be used. As wet etching, a method of immersing in dilute hydrochloric acid or dilute sulfuric acid can be used. Note that when etching is performed, a layer through which the opening 17 passes can be selected by adjusting etching conditions (processing time, gas used, pressure, substrate temperature).

  The patterning of the opening 17 may be performed at the same time as the formation of the insulating layer 13. In this case, the insulating layer 13 may be formed by resistance heating vapor deposition using a mask in which the same pattern as the pattern of the opening 17 is formed. The film can be formed by a film forming method such as a printing method for drawing the insulating layer 13 while leaving the pattern of the opening 17.

(Patterning method of the first electrode 14)
As a patterning method for the first electrode 14, a method such as photolithography can be used in the same manner as the method for forming the opening 17 described above. The patterning of the first electrode 14 may be performed simultaneously with the film formation or after the film formation.

  In the light emitting device to which the present embodiment is applied, an angle formed between the direction of the first major axis in the opening 17 and the direction of the second major axis in the first electrode 14 in all sections of the light emitting region. (Θ) is constant.

In patterning using a mask such as photolithography, the patterns of the plurality of openings 17 and the plurality of first electrodes 14 are made the same among the plurality of sections, so that each section is patterned using the same mask. Manufacturing is easy.
Here, the patterns of the plurality of openings 17 and the plurality of first electrodes 14 are the same between the sections. The shapes and sizes of the openings 17 and the first electrodes 14, the openings 17 and the first electrodes 14, and the like. The interval between 14 is the same in any section, and the direction of the first major axis in the opening 17 and the second major axis in the first electrode 14 may be different for each section.

(Method for manufacturing light emitting device)
The manufacturing process of the light emitting device to which this embodiment is applied basically includes the following processes.
(1) Step of preparing one planar conductor (2) Step of forming an insulating layer having a plurality of openings on the upper surface of the planar conductor (3) The first electrode A and the first electrode on the insulating layer Step of forming one electrode B (here, a plurality of first electrodes so that the angle formed by the first major axis of the opening and the second major axis of the first electrode A is a constant angle in the entire light emitting region) Form)
(4) Step of forming an organic compound layer including a light emitting layer so as to cover the plurality of first electrodes (5) Step of forming a second electrode on the organic compound layer

Here, a light-emitting device having a luminance distribution (luminance unevenness) of a predetermined value or less can be manufactured by the following procedure.
(A) In the above manufacturing process, the light emitting region is divided into a plurality of sections from a region near the terminal portion to a region far from the terminal portion, and the ratio of the number of first electrodes B to the total number of first electrodes is far from the terminal portion. The first light-emitting device is manufactured by setting the angle between the first long axis of the opening and the second long axis of the first electrode A to a constant value θ ₁ so that the section becomes larger (see FIG. 5). .
(B) The luminance distribution (luminance unevenness) of the first light emitting device is measured.
(C) When the measured value of the luminance distribution (brightness unevenness) is equal to or greater than a predetermined value, the angle formed by the first major axis and the second long axis is θ ₁ so that the luminance distribution (brightness unevenness) is reduced. Manufactures the second light emitting device at different constant angles θ ₂ (d) Measures the luminance distribution (luminance unevenness) of the second light emitting device.
(E) When the measured value of the luminance distribution (brightness unevenness) is equal to or greater than a predetermined value, the angle formed by the first long axis and the second long axis is θ so that the luminance distribution (brightness unevenness) is further reduced. The third light emitting device is manufactured at a constant angle θ ₃ different from ₂ . Such an operation is repeated until a luminance distribution (luminance unevenness) of a predetermined value or less is obtained.

  In the manufacture of a light emitting device having a small luminance distribution (brightness unevenness), when patterning the first electrode 14 or the opening 17 using photolithography, the angle θ is changed by changing the relative angle between the substrate 11 and the photomask. Can be changed. Thus, a light emitting device with a small luminance distribution (luminance unevenness) can be manufactured by an easy method. Further, in the light emitting device of the present embodiment, it is possible to cope with luminance distributions (luminance unevenness) different for each element only by selecting an appropriate relative angle between the substrate 11 and the photomask.

  In order to stably use the light emitting device of this embodiment for a long period of time, it is preferable to attach a protective layer or a protective cover for protecting the light emitting device from the outside. As the protective layer, a polymer compound, metal oxide, metal fluoride, metal boride, silicon nitride, silicon oxide, or the like can be used. And these laminated bodies can also be used. Further, as the protective cover, a glass plate, a plastic plate whose surface has been subjected to low water permeability treatment, a metal, or the like can be used. For such a protective cover, it is preferable to employ a method in which a thermosetting resin or a photocurable resin is attached to the element substrate and sealed.

  In this case, it is preferable to use a spacer because a predetermined space can be secured and the light emitting unit 10 can be prevented from being damaged. Then, by filling an inert gas such as nitrogen, argon, or helium in such a space, it becomes easy to prevent the upper second electrode 16 from being oxidized. In particular, it is preferable to use helium because heat conduction is high, and thus heat generated from the light emitting device when voltage is applied can be effectively transmitted to the protective cover. Furthermore, by installing a desiccant such as barium oxide in such a space, it becomes easy to suppress the moisture adsorbed in the series of manufacturing steps from damaging the light emitting device.

  The light-emitting device of this embodiment can be used for a surface-emitting light source or the like. Specifically, it is suitably used for backlights, electrophotography, illumination, resist exposure, reading devices, interior illumination, optical communication systems and the like in display devices.

DESCRIPTION OF SYMBOLS 10 ... Light emission part, 11 ... Board | substrate, 12 ... Conductor, 13 ... Insulating layer, 14 ... 1st electrode, 14A ... 1st electrode A, 14B ... 1st electrode B, 15 ... Organic compound layer, 16 ... 2nd electrode , 17 ... opening, 18 ... terminal part

Claims (10)

A light-emitting device having a light-emitting region composed of a plurality of light-emitting portions having a minimum width of 0.1 μm to 10 μm that are electrically connected in parallel,
The light emitting region is
One planar conductor;
An insulating layer formed on the upper surface of the planar conductor,
A plurality of openings formed in the insulating layer;
A plurality of first electrodes formed on the insulating layer;
An organic compound layer including a light emitting layer formed to cover the plurality of first electrodes;
A second electrode formed on the organic compound layer,
At least a part of the plurality of first electrodes is also formed in the opening and electrically connected to the conductor, thereby forming an electrode for energizing the organic compound layer in the plurality of light emitting portions,
The plurality of openings have an elongated shape having a first major axis and a first minor axis orthogonal to each other in a plan view, and the first major axes are parallel to each other in the light emitting region. Formed into
The plurality of first electrodes are composed of two types of electrodes having different shapes, and one is a first electrode A having an elongated shape having a second major axis and a second minor axis orthogonal to each other in plan view, and the other Is a first electrode B having a shape having a third major axis and a third minor axis that are orthogonal to each other in plan view, and the plurality of first electrodes A having the second major axis include the light emitting region. The plurality of first electrodes B having the third long axis are parallel to each other in the light emitting region. Formed to be
The distance between the openings in the first short axis direction of the openings is longer than the length of the second short axis of the first electrode A, and the third short axis of the first electrode B. A light emitting device characterized by being shorter than the length of the light emitting device.   The first long axis of the opening is at least five times longer than the first short axis, and the second long axis of the first electrode A is at least five times longer than the second short axis. 2. The light emitting device according to claim 1, wherein the third major axis of the first electrode B is 1 to 2 times as long as the third minor axis.   The angle (θ) formed by the first long axis of the opening and the second long axis of the first electrode A is 0 to 80 degrees. Light-emitting device.   2. The first electrode A electrically connected to the conductor and the first electrode A not connected to the conductor are mixed in the light emitting region. 4. The light emitting device according to any one of 3.   The distance between the openings in the first short axis direction of the openings is shorter than the length of the second major axis of the first electrode A. 5. 2. The light emitting device according to item 1. The length of the first short axis of the opening, the length of the second short axis of the first electrode A, and the length of the third short axis of the first electrode B are respectively 0. The opening and the first electrode are 10 ² to 10 ⁸ in an arbitrary 1 mm square region of the light emitting region, respectively. The light-emitting device of any one of Claims.   7. The light emitting device according to claim 6, wherein a ratio of the area occupied by the first electrode is 50% or more in an arbitrary 1 mm square region in the light emitting region in a plan view.   8. The opening according to any one of claims 1 to 7, wherein the openings are formed in the light emitting region so that the first long axes face each other in parallel and periodically. The light-emitting device of description. The conductor is a transparent conductive film made of a metal oxide, and is formed on at least a part of the outside of the light emitting region, and has a terminal portion that is electrically connected to the conductor and connected to a power source. ,
In the light emitting region, the ratio of the number of the first electrodes B to the total number of the first electrodes is larger in a region farther from the terminal portion, and
9. The light emitting device according to claim 1, wherein an angle formed by the first long axis and the second long axis is constant in the light emitting region. A method for reducing the luminance distribution of the light emitting device according to claim 9, comprising:
A first light-emitting device is manufactured using a method for manufacturing a light-emitting device including the steps shown in the following (1) to (5),
(1) A step of preparing one planar conductor,
(2) forming an insulating layer having a plurality of openings on the upper surface of the planar conductor;
(3) forming a plurality of first electrodes on the insulating layer so that an angle formed by the first major axis and the second major axis is a constant angle θ ₁ ;
(4) forming an organic compound layer including a light emitting layer so as to cover the plurality of first electrodes;
(5) forming a second electrode on the organic compound layer;
When the luminance distribution of the first light emitting device is measured and the luminance distribution is not within a predetermined range, in the method of manufacturing the light emitting device, the first long axis and the first A method for reducing the luminance distribution of a light emitting device, wherein the second light emitting device is manufactured by setting the angle formed by the major axis of 2 to a constant angle θ ₂ different from θ ₁ .

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