KR102332549B1 - Organic light emitting diode and organic light emittind display device having the same - Google Patents

Abstract

a first electrode, a light emitting part positioned on the first electrode, and a second electrode positioned on the light emitting part, wherein the light emitting part is sequentially positioned from the first electrode to a hole transport layer, a blue light emitting layer, and an electron transport layer. a hole transport layer, the blue emission layer, and the electron transport layer, the blue emission layer includes a blue host material and a blue fluorescent dopant material, the hole transport layer includes a hole transport layer material, and the electron transport layer includes an electron transport layer material. a lowest unoccupied molecular orbital (LUMO) energy level of the blue fluorescent dopant material is higher than a LUMO energy level of the blue host material, and a highest occupied (HOMO) energy level of the blue fluorescent dopant material. Molecular Orbital) energy level is above the HOMO energy level of the blue host material, the magnitude of the singlet energy of the blue fluorescent dopant material is smaller than the singlet energy of the blue host material, and the HOMO energy of the hole transport layer material the level is above the HOMO energy level of the blue host material, the HOMO energy level of the hole transport layer material is above the HOMO energy level of the blue fluorescent dopant material, and the difference between the two energies is 0.1 eV or less; The LUMO energy level of the hole transport layer material is above the LUMO energy level of the blue host material, the difference between the two energies is 0.5 eV or more, and the LUMO energy level of the hole transport layer material is above the LUMO energy level of the blue fluorescent dopant material. wherein the LUMO energy level of the electron transport layer material is above the LUMO energy level of the blue host material, and the LUMO energy level of the electron transport layer material is above the LUMO energy level of the blue fluorescent dopant material; The difference is less than or equal to 0.1 eV, T _{1 , HTL} , T _{1 , ETL} and When T _{1 , BH} represents each triplet energy of the hole transport layer material, the electron transport layer material, and the blue host material, T _{1 , BH between the three triplet energies} < T _{1 , HTL} and T _{1 , BH} < T _{1 ,} there is a relationship of _{ETL , 2.8 < T 1 , HTL} <3.0 and 2.6< T _{1 , ETL} An organic light emitting diode having a range of <2.8 is provided.

Description

Organic light emitting diode and organic light emitting display device including same

The present invention relates to an organic light emitting diode and an organic light emitting display device including the same.

BACKGROUND ART As display devices become larger, interest in flat display devices that occupy less space is increasing with the recent enlargement of display devices. The technology of an organic light emitting diode (OLED) device including an organic light emitting diode (OLED) as one of such flat display devices is rapidly developing.

An organic electroluminescent device is a device that injects an electric charge into an organic light emitting layer formed between an anode and a cathode to form excitons (excitons) by pairing electrons and holes, and then emits the energy of the excitons as light. Compared to the conventional display technology, the organic light emitting diode has the advantage of being able to drive at a low voltage, consume relatively little power, have excellent color, and can be applied to a flexible substrate so that it can be used in a variety of ways.

In general, an organic light emitting device can be divided into a single light emitting device (Single OLED) and a multilayer light emitting device (Tandem OLED) according to the number of light emitting units. A multilayer light emitting device (Tandem OLED) is an OLED device composed of two or more light emitting units (stack), and it is easier to improve the driving voltage and efficiency compared to the conventional single OLED.

In the case of the blue light emitting layer used in the existing white organic light emitting diode (WOLED), the characteristics during electron or hole injection at the interface are lowered due to the difference in energy level between the functional layers constituting the light emitting layer, which adversely affects device performance and lifespan.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an organic light emitting diode and an organic light emitting display device capable of lowering a driving voltage and having improved light emitting performance and lifetime of a device.

In one embodiment of the present invention, there is provided an organic light emitting diode including a first electrode, a light emitting part positioned on the first electrode, and a second electrode positioned on the light emitting part.

The light emitting unit includes the hole transport layer, the blue light emitting layer and the electron transport layer so that the hole transport layer, the blue light emitting layer and the electron transport layer are sequentially positioned from the first electrode.

The blue light emitting layer includes a blue host material and a blue fluorescent dopant material.

The hole transport layer includes a hole transport layer material.

The electron transport layer includes an electron transport layer material.

A lowest unoccupied molecular orbital (LUMO) energy level of the blue fluorescent dopant material is higher than a LUMO energy level of the blue host material.

A Highest Occupied Molecular Orbital (HOMO) energy level of the blue fluorescent dopant material is above the HOMO energy level of the blue host material.

The magnitude of the singlet energy of the blue fluorescent dopant material is smaller than the singlet energy of the blue host material.

The HOMO energy level of the hole transport layer material is above the HOMO energy level of the blue host material.

The HOMO energy level of the hole transport layer material is higher than the HOMO energy level of the blue fluorescent dopant material, and the difference between the two energies is 0.1 eV or less.

The LUMO energy level of the hole transport layer material is higher than the LUMO energy level of the blue host material, and the difference between the two energies is 0.5 eV or more.

The LUMO energy level of the hole transport layer material is above the LUMO energy level of the blue fluorescent dopant material.

The LUMO energy level of the electron transport layer material is above the LUMO energy level of the blue host material.

The LUMO energy level of the electron transport layer material is higher than the LUMO energy level of the blue fluorescent dopant material, and the difference between the two energies is 0.1 eV or less.

T _{1 , HTL} , T _{1 , ETL} and When T _{1 , BH} represents each triplet energy of the hole transport layer material, the electron transport layer material, and the blue host material, T _{1 , BH between the three triplet energies} < T _{1 , HTL} and T _{1 , BH} < T _{1 ,} there is a relationship of _{ETL , 2.8 < T 1 , HTL} <3.0 and 2.6< T _{1 , ETL} It has a range of <2.8.

The organic light emitting diode can achieve improved driving characteristics and long life while including a blue light emitting layer.

1 is an energy diagram schematically illustrating energy levels of a hole transport layer (HTL), a blue light emitting layer (B-EML), and an electron transport layer (ETL) of the organic light emitting diode.
2 is a cross-sectional view schematically illustrating an organic light emitting diode according to an exemplary embodiment of the present invention.
3 is a cross-sectional view schematically illustrating an organic light emitting diode according to another exemplary embodiment of the present invention.
4 is a cross-sectional view schematically illustrating an organic light emitting diode according to another exemplary embodiment of the present invention.
5 is a cross-sectional view schematically illustrating an organic light emitting display device according to an exemplary embodiment of the present invention.
6 is an energy diagram schematically illustrating the energy level of the organic light emitting diode of Example 1. Referring to FIG.
7 is an energy diagram schematically illustrating an energy level of an organic light emitting diode of Comparative Example 1. Referring to FIG.

Hereinafter, with reference to the drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are given to the same or similar elements throughout the specification. Further, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

In the following, the provision or arrangement of an arbitrary component on the “upper (or lower)” or “top (or below)” of the substrate means that any component is provided or disposed in contact with the upper surface (or lower surface) of the substrate. It is not intended to mean, but is not limited to, the inclusion of other components between the substrate and any component provided or disposed on (or under) the substrate. In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, order, or number of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but other components may be interposed between each component. It will be understood that each component may be “interposed” or “connected,” “coupled,” or “connected” through another component.

In one embodiment of the present invention, there is provided an organic light emitting diode including a first electrode, a light emitting part positioned on the first electrode, and a second electrode positioned on the light emitting part.

The light emitting unit includes the hole transport layer, the blue light emitting layer and the electron transport layer such that the hole transport layer, the blue light emitting layer and the electron transport layer are sequentially positioned from the first electrode.

The blue light emitting layer includes a blue host material and a blue fluorescent dopant material. The hole transport layer includes a hole transport layer material. The electron transport layer includes an electron transport layer material.

The light emitting unit satisfies conditions (A) to (C) of the following energy levels.

(A) a lowest unoccupied molecular orbital (LUMO) energy level of the blue fluorescent dopant material is above the LUMO energy level of the blue host material,

(B) the HOMO (Highest Occupied Molecular Orbital) energy level of the blue fluorescent dopant material is above the HOMO energy level of the blue host material,

(C) the magnitude of the singlet energy of the blue fluorescent dopant material is smaller than the singlet energy of the blue host material,

(d) the HOMO energy level of the hole transport layer material is above the HOMO energy level of the blue host material,

(E) the HOMO energy level of the hole transport layer material is higher than the HOMO energy level of the blue fluorescent dopant material, and the difference between the two energies is 0.1 eV or less,

(F) the LUMO energy level of the hole transport layer material is above the LUMO energy level of the blue host material, and the difference between the two energies is 0.5 eV or more,

(G) the LUMO energy level of the hole transport layer material is above the LUMO energy level of the blue fluorescent dopant material,

(H) the LUMO energy level of the electron transport layer material is above the LUMO energy level of the blue host material,

(I) The LUMO energy level of the electron transport layer material is higher than the LUMO energy level of the blue fluorescent dopant material, and the difference between the two energies is 0.1 eV or less.

(Car) T _{1 , HTL} , T _{1 , ETL} and When T _{1 , BH} represents each triplet energy of the hole transport layer material, the electron transport layer material, and the blue host material, T _{1 , BH between the three triplet energies} < T _{1 , HTL} and T _{1 , BH} < T _{1 ,} there is a relationship of _{ETL , 2.8 < T 1 , HTL} <3.0 and 2.6< T _{1 , ETL} It represents a range of <2.8.

The organic light emitting diode including a light emitting part that satisfies the energy level conditions of the blue fluorescent dopant material and the blue host material as described above facilitates injection characteristics and coupling of electrons and holes in the blue light emitting layer, thereby generating excitons. It is confined in the light emitting layer, and through this, improved driving characteristics and long life can be achieved.

In the organic light emitting diode including the hole transport layer satisfying the HOMO energy level condition of the hole transport layer material as described above, holes are injected from the anode through the hole transport layer into the light emitting layer, and in the case of the blue fluorescent dopant material constituting the light emitting layer The hole characteristics are strongly displayed. In this case, it is possible to improve hole injection from the hole transport layer to the light emitting layer by reducing the difference in HOMO energy level between the blue fluorescent dopant material exhibiting hole characteristics and the hole transport layer. The organic light emitting diode can achieve improved driving characteristics and long life through this.

In the organic light emitting diode including a light emitting part including a blue light emitting layer and a hole transport layer satisfying the LUMO energy level condition of the blue host material, the blue fluorescent light emitting dopant material, and the hole transport layer material, the distribution of electrons is in the blue light emitting layer It is limited to , so that the generation of excitons can be efficiently controlled. In addition, by preventing excitons generated in the blue light emitting layer from moving to the hole transport layer, an additional reaction and energy loss due to the excitons are prevented. Accordingly, in the organic light emitting diode, it is possible to prevent an addition reaction that may be caused by excitons moving to the hole transport layer, thereby preventing a change in charge transfer characteristics due to impurities generated by the addition reaction, and maintaining the driving characteristics of the device. In addition, the organic light emitting diode can increase luminous efficiency by limiting a place where exciton energy is used to the blue light emitting layer. The organic light emitting diode can achieve improved driving characteristics and long life through this.

In the case of an organic light emitting diode in which an electron transport layer including the blue host material, the blue fluorescent dopant material, and a material satisfying the LUMO energy level condition is interposed between the second electrode and the blue light emitting layer, transport from the second electrode The generated electrons are effectively injected into the blue light emitting layer to efficiently control the generation of excitons. The organic light emitting diode can achieve improved driving characteristics and long life through this.

When excitons are formed in the blue light emitting layer, excitons having singlet energy and triplet energy are formed in a 1:3 ratio. Triplet excitons have a relatively long lifetime compared to singlet excitons. At this time, the triplet excitons may move to the hole transport layer and the electron transport layer around the light emitting layer to react with the constituent materials of the functional layer. The reaction forms a by-product in the functional layer, thereby changing the composition of the functional layer. The by-products change the transfer characteristics and injection characteristics of electric charges moving through each functional layer, thereby breaking the electron-hole balance in the device. As a result, the driving characteristics of the device are changed, and deterioration of the device occurs, resulting in a decrease in lifespan. The hole transport layer and the electron transport layer having the triplet energy range defined in condition (h) above restrict the movement of triplet excitons formed in the blue light emitting layer, thereby preventing secondary reactions occurring in each functional layer. In this way, deterioration of the device is prevented and long life is achieved.

1 is an energy diagram schematically illustrating energy levels of a hole transport layer (HTL), a blue light emitting layer (B-EML), and an electron transport layer (ETL) of the organic light emitting diode. In FIG. 1 , a blue light emitting layer (B-EML) is divided into a blue fluorescent dopant material (BD) and a blue host material (BH).

In FIG. 1 , the energy level of each layer of the organic light emitting diode satisfies conditions (A) to (C) of the above-described energy level. Specifically, as shown in FIG. 1 , (a) the LUMO energy level of the blue fluorescent dopant material (BD) is higher than the LUMO energy level of the blue host material (BH). Also, as shown in FIG. 1 , (B) the HOMO energy level of the blue fluorescent dopant material BD is higher than the HOMO energy level of the blue host material BH. In the excitation level energy graph on the right side of FIG. 1 , (C) the singlet energy of the fluorescent dopant BD is smaller than the singlet energy of the host BH. In FIG. 1 , (d) the HOMO energy level of the hole transport layer (HTL) material is higher than the HOMO energy level of the blue host material (BH). In FIG. 1 , ΔE ₁ (E) represents a difference caused by the HOMO energy level of the hole transport layer (HTL) material being higher than the HOMO energy level of the blue fluorescent dopant material (BD). The difference between the HOMO energy level of the hole transport layer material and the HOMO energy level of the blue fluorescent dopant material is 0.1 eV or less. That is, ΔE ₁ ≤ 0.1 eV. In FIG. 1 , ΔE ₂ represents a difference caused by (bar) the LUMO energy level of the hole transport layer (HTL) material being higher than the LUMO energy level of the blue host material (BH). A difference between the LUMO energy level of the hole transport layer (HTL) material and the LUMO energy level of the blue host material (BH) is 0.5 eV or more. That is, ΔE ₂ ≥ 0.5 eV. In FIG. 1 , (g) the LUMO energy level of the hole transport layer (HTL) material is higher than the LUMO energy level of the blue fluorescent dopant material (BD). 1 , (H) the LUMO energy level of the electron transport layer (ETL) material is higher than the LUMO energy level of the blue host material (BH). In FIG. 1 , ΔE ₂ represents a difference that occurs because the LUMO energy level of the electron transport layer (ETL) material is higher than the LUMO energy level of the blue fluorescent dopant material (BD). The difference between the LUMO energy level of the electron transport layer (ETL) material and the LUMO energy level of the blue fluorescent dopant material BD is 0.1 eV or less. That is, ΔE ₂ ≤ 0.1 eV. In Figure 1, (car) T _{1 , BH} < T _{1 , HTL} and T _{1 , BH} There is a triplet energy relationship of < T _{1 , ETL , 2.8 < T 1 , HTL} <3.0 and 2.6< T _{1 , ETL} It has a range of <2.8.

2 is a cross-sectional view schematically illustrating an organic light emitting diode 100 including a first electrode 110 , a light emitting unit 140 , and a second electrode 120 according to an exemplary embodiment of the present invention. The light emitting unit 140 includes a hole transport layer (HTL, 141), a blue light emitting layer (B-EML, 142) in contact with the hole transport layer (HTL, 141), and the electrons in contact with the blue light emitting layer (B-EML, 142). and a transport layer (ETL) 144 .

The first electrode 120 is an anode for injecting holes, and a conductive material having a high workfunction, for example, indium-tin-oxide (ITO), indium-zinc- The oxide (Indium-zinc-oxide, IZO) and zinc-oxide (ZnO) may be formed of any one conductive material.

The second electrode 120 is a cathode for injecting electrons, and may be made of a conductive material having a small work function, for example, any one of aluminum (Al), magnesium (Mg), and an aluminum-magnesium alloy (AlMg). have.

The light emitting unit 140 includes the hole transport layer (HTL, 141), the blue light emitting layer (BML, 142) and the electron transport layer (ETL) positioned between the first electrode 110 and the second electrode 120 , 144).

The hole transport layer HTL 141 is positioned between the first electrode 110 and the blue light emitting layer B-EML 142 .

The hole transport layer (HTL, 141) is each N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (N,N'- diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, TPD), NPD, MTDATA, 1,3-bis(N-carbazolyl)benzene (1, 3-bis(N-carbazolyl)benzene, mCP), CuPC, TCTA, tris(trifluorovinyl ether)-tris(4-carbazolyl-9-yl-phenyl)amine(tris(trifluorovinyl ether)-tris(4- carbazoyl-9-yl-phenyl)amine, TFV-TCTA), tris[4-(diethylamino)phenyl]amine), N-(biphenyl-4-yl) -9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, tri-p-tolylamine, N-[1,1'-biphenyl]-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine (N-[1 ,1'-biphenyl]-4-yl-9,9-diMethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine), 4,4'-bis(N- Carbazolyl)-1,1'-biphenyl (4,4'-bis(N-carbazolyl)-1,1'-biphenyl, CBP) and/or 1,1-bis(4-(N,N'- Di (p-tolyl) amino) phenyl) cyclohexane (1,1-bis (4- (N,N'-di (ptolyl) amino) phenyl) cyclohexane, TAPC) any one substance selected from the group consisting of can be made with

In one embodiment, the hole transport layer (HTL, 141) material may be a tertiary substituted amine compound.

The blue emission layer B-EML 142 includes a blue host material BH and a blue fluorescent dopant material BD.

In an embodiment, the blue host material (BH) may include an anthracene-based material. Specifically, the blue host material (BH) is 9,10-di-(2-naphthyl)anthracene (9,10-di-(2-naphtyl)anthracene, ADN), 2-tert-butyl-9,10 -di (2-naphthyl) anthracene (2-tert-butyl-9,10-di (2-naphthyl) anthracene), 2-methyl-9,10-di (2-naphthyl) anthracene (2-methyl- 9,10-di(2-naphtyl)anthracene, MADN) and a blue fluorescent host material (BH) including one selected from the group consisting of combinations thereof.

In one embodiment, the blue fluorescent dopant material (BD) may include a pyrene amine derivative material. Specifically, the blue fluorescent dopant material (BD) may be selected from 1,6-Bis(diphenylamine)pyrene, TBPe(tetrakis(t-butyl)perylene), and the like, and a combination of two or more is possible, but is not limited thereto. .

The blue emission layer B-EML 142 may include the blue fluorescent dopant material BD in an amount of 1 to 5 wt%. The blue light emitting layer B-EML 142 may include the blue fluorescent light emitting dopant material BD in the content range to effectively satisfy the above-described energy level condition. When the content of the blue fluorescent dopant material (BD) exceeds the above range, concentration quenching occurs between the dopant materials, thereby reducing efficiency at high luminance. On the other hand, when the content of the blue fluorescent dopant material (BD) is less than the above range, it is difficult to transfer energy from the host to the dopant, so that a desired level of light emitting properties cannot be obtained, and side reactions occur in the light emitting layer, which can cause a decrease in lifespan. have.

The electron transport layer HTL 144 may be positioned between the blue light emitting layer B-EML 142 and the second electrode 120 , and serves to facilitate electron transport.

For example, the electron transport layer (HTL, 144) material is oxadiazole, triazole, phenanthroline, benzoxazole, benzothiazole, benzimidazole, It may be a derivative such as triazine.

Specifically, the electron transport layer (HTL, 144) is Alq3, 2-biphenyl-4-yl-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (2-biphenyl-4) -yl-5-(4-tbutylphenyl)-1,3,4-oxadiazole, PBD), spiro-PBD, lithium quinolate (Liq), 2-[4-(9,10-di-2- Naphthalenyl-2-anthracenyl)phenyl]-1-phenyl-1H-benzimidazole(2-[4-(9,10-Di-2-naphthalenyl-2-anthracenyl)phenyl]-1-phenyl-1Hbenzimidazol ), 3-(biphenyl-4-yl)-5-(4-tertbutylphenyl)-4-phenyl-4H-1,2,4-triazole (3-(biphenyl-4-yl)-5- (4-tertbutylphenyl)-4-phenyl-4H-1,2,4-triazole, TAZ), 4,7-diphenyl-1,10-phenanthroline (4,7-diphenyl-1,10-phenanthroline, Bphen), tris(phenylquinoxaline) (tris(phenylquinoxaline, TPQ), 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene (1,3,5-Tri[(3) -pyridyl)-phen-3-yl]benzene, TmPyPB) and/or 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (1,3,5-tris(N-phenylbenzimiazole- It may be made of an electron transport material such as 2-yl)benzene or TPBI).

In one embodiment, the electron transport layer (HTL, 144) material may be a pyrimidine-based material.

Optionally, each of the electron transport layers HTL 144 may be doped with an alkali metal or alkaline earth metal compound. A metal component that can be used as a dopant of the electron transport layer (HTL, 144) is an alkali metal such as lithium (Li), sodium (Na), potassium (K) and cesium (Cs) and/or magnesium (Mg), strontium ( Sr), barium (Ba), and alkaline earth metals such as radium (Ra), but are not limited thereto. The alkali metal or alkaline earth metal compound may be added in a proportion of approximately 1 to 20 wt%, but is not limited thereto.

The light emitting unit 140 may optionally further include one or more layers of a hole injection layer (HIL), an electron injection layer (EIL), and the like, as necessary.

The hole injection layer HIL may be positioned between the first electrode 120 and the hole transport layer 142 (HTL). The hole injection layer HIL improves the interface characteristics between the inorganic material first electrode 120 and the organic hole transport layer 142 (HTL).

For example, the hole injection layer (HIL) is 4,4',4"-tris(3-methylphenylphenylamino)triphenylamine (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine, MTDATA), Copper phthalocyanine (CuPc), Tris(4-carbazoyl-9-yl-phenyl)amine (TCTA), N,N'-diphenyl-N ,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine (N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1' -biphenyl-4,4"-diamine, NPB, NPD), 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile, HATCN), 1,3,5-tris[4-(diphenylamino)phenyl]benzene (1,3,5-tris[4-(diphenylamino)phenyl]benzene, TDAPB), poly(3,4-ethylenediox) Thiophene) polystyrene sulfonate (poly (3,4-ethylenedioxythiphene) polystyrene sulfonate, PEDOT/PSS), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane ( 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, F4-TCNQ), and/or N-(biphenyl-4-yl)-9,9-dimethyl-N-(4- (9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine (N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-) phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine) and the like).

The electron injection layer EIL may be positioned between the electron transport layer ETL and the second electrode 120 , and serves to facilitate electron injection. For example, an electron injection layer (EIL) are LiF, NaF, KF, RbF, CsF, FrF, BeF _2, MgF _2, CaF _2, SrF _2, BaF ₂ and RaF ₂ such as an alkali halide-based material and / or Liq of (lithium quinolate), lithium benzoate (lithium benzoate), sodium stearate, Alq ₃ , BAlq, PBD, spiro-PBD, may include an organic material such as TAZ.

3 is a cross-sectional view schematically illustrating an organic light emitting diode 200 including a first electrode 210 , a light emitting unit 240 , and a second electrode 220 according to another exemplary embodiment of the present invention. In FIG. 3 , the light emitting unit 240 includes a hole injection layer (HIL, 243), a hole transport layer (HTL, 241), a blue light emitting layer (B-EML, 242), an electron transport layer (ETL, 244) and an electron injection layer (EIL). , 245). A detailed description of each layer of the organic light emitting diode 200 is the same as described above.

The organic light emitting diode may have a tandem structure including at least two light emitting units.

In an embodiment, the light emitting units 142 and 242 are first light emitting units, and may further include at least one additional light emitting unit including a second light emitting unit between the first electrode and the second electrode.

4 is a view showing a first electrode 310 , a first light emitting part ST1 and 340 , a charge generation layer CGL 360 , and a second light emitting part ST2 according to another exemplary embodiment of the present invention. , 350 ) and a cross-sectional view schematically illustrating the organic light emitting diode 300 including the second electrode 320 . In FIG. 4 , the first light emitting units ST1 and 340 include a first hole transport layer HTL, 341 , a first blue light emitting layer 342 , and a first electron transport layer ETL 344 , and the second light emission The units ST2 and 350 include a second hole transport layer HTL 351 , a second blue light emitting layer 352 , and a second electron transport layer ETL 354 . In addition, each of the first light emitting units ST1 and 340 and the second light emitting unit ST2 and 350 may further include an organic layer such as a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer, if necessary. . A detailed description of each layer of the organic light emitting diode 300 is the same as described above.

The organic light emitting diode 300 increases the efficiency of the current generated in each light emitting layer between the first light emitting units ST1 and 340 and the second light emitting unit ST2 and 350 so that charges can be smoothly distributed. A charge generation layer (CGL, 360) is positioned. That is, the charge generation layer 360 is positioned between the first light emitting units ST1 and 340 and the second light emitting units ST2 and 350 , and includes the first light emitting units ST1 and 340 and the second light emitting unit ST2 , 350 is connected by the charge generation layer 360 . The charge generation layer 360 may be a PN-junction charge generation layer in which the N-type charge generation layer 362 and the P-type charge generation layer 364 are adjacently positioned and joined.

The N-type charge generation layer 362 is positioned to face the first light-emitting units ST1 and 340 , and the P-type charge generation layer 364 is positioned to face the second light-emitting unit 350 . The charge generation layer 360 supplies electrons and holes to the first and second light emitting units 340 and 350 by generating charges or separating them into holes and electrons.

That is, the N-type charge generation layer 362 supplies electrons to the first light emitting units ST1 and 340 , and supplies electrons to the first light emitting units ST1 and 340 adjacent to the first electrode 310 . Meanwhile, the P-type charge generating layer 364 supplies holes to the second light emitting units ST2 and 350 , and the second hole transport layer 351 is adjacent to the second light emitting unit ST2 and 350 . ) to supply holes.

The N-type charge generation layer 362 is configured as a host-dopant system, and may include an N-type dopant material and an N-type host material. The N-type dopant material may be a metal of Groups 1 and 2 on the periodic table, an organic material capable of electron injection, or a mixture thereof. For example, the N-type dopant material may be any one of an alkali metal and an alkaline earth metal. That is, the N-type charge generation layer 362 is an alkali metal such as lithium (Li), sodium (Na), potassium (K), or cesium (Cs), or magnesium (Mg), strontium (Sr), barium (Ba). ), or an organic layer doped with an alkaline earth metal such as radium (Ra), but is not limited thereto. The N-type host material is a material capable of transferring electrons, for example, Alq3 (tris(8-hydroxyquinolino)aluminum), Liq(8-hydroxyquinolinolato-lithium), PBD(2-(4-biphenylyl)-5-( 4-tert-butylphenyl)-1,3,4oxadiazole), TAZ(3-(4-biphenyl)4-phenyl-5-tert-butylphenyl-1,2,4-triazole), spiro-PBD, and BAlq(bis (2-methyl-8-quinolinolate)-4-(phenylphenolato)aluminium), SAlq, TPBi(2,2',2-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) ), oxadiazole, triazole, phenanthroline, benzoxazole or benzthiazole may consist of any one or more selected from the group consisting of, but not limited to does not

Alternatively, the N-type charge generation layer 362 may not be configured as a host-dopant system. That is, the N-type charge generation layer 362 may not include an N-type dopant material.

The P-type charge generation layer 364 may include a P-type dopant material and a P-type host material. The P-type charge generation layer 364 is disposed on the N-type charge generation layer 362 and has a structure bonded to the N-type charge generation layer 362 . The P-type dopant material is an organic material such as metal oxide, tetrafluoro-tetracyanoquinodimethane (F4-TCNQ), Hexaazatriphenylenehexacarbonitrile (HAT-CN), hexaazatriphenylene, or V ₂ O ₅ , MoO _x , WO ₃ It may be made of a metal material such as, but is not necessarily limited thereto. The P-type host material is a material capable of transporting holes, for example, NPD (N,N-dinaphthyl-N,N'-diphenyl benzidine) (N,N'-bis(naphthalene-1-yl)-N, N'-bis(phenyl)-2,2'-dimethylbenzidine), TPD(N,N'-bis-(3-methylphenyl)-N,N'-bis-(phenyl)-benzidine) and MTDATA(4,4) ',4-Tris(N-3-methylphenyl-N-phenyl-amino)-triphenylamine) may be made of a material including at least one selected from the group consisting of, but is not necessarily limited thereto.

The additional light emitting unit may emit red (R), green (G), or yellow (Yellow, Y) light.

In one exemplary embodiment, the first light-emitting units ST1 and 340 emit blue light, and the second light-emitting units ST2 and 350 emit green (G), yellow-green (YG), and yellow (Y) having a longer wavelength than blue. ) or can emit orange color.

In one embodiment, the organic light emitting diode may be a white organic light emitting diode having light emitting characteristics of red (R), green (G), and blue (B), which are the three primary colors of white light. For example, in the white organic light emitting diode, the first light emitting units ST1 and 340 emit blue light, and the second light emitting units ST2 and 350 include one host and a yellow dopant, so that blue (B) and By having the yellow (Y) light emitting characteristic, white light can be realized. When the white organic light emitting diode is driven, white light is realized by the mixing effect of the light emitted from the first light emitting units ST1 and 340 and the second light emitting unit ST2 and 350 .

The organic light emitting diode may be used in an organic light emitting display device and a lighting device to which the organic light emitting diode is applied.

In another embodiment of the present invention, there is provided an organic light emitting display device including a substrate, the organic light emitting diode positioned on the substrate, and a driving element positioned between the substrate and the organic light emitting diode and connected to the first electrode. to provide.

For example, FIG. 5 is a cross-sectional view schematically illustrating an organic light emitting diode display according to an exemplary embodiment of the present invention.

As shown in FIG. 5 , the organic light emitting diode display 400 may include a substrate 401 , an organic light emitting diode 500 , and an encapsulation layer 490 covering the organic light emitting diode 500 . . A driving thin film transistor Td as a driving element and an organic light emitting diode 500 connected to the driving thin film transistor Td are positioned on the substrate 401 .

Although not shown, on the substrate 401 , a gate line crossing each other and defining a pixel region, a data line, a power line extending parallel to any one of the gate line and the data line, and a switching connected to the gate line and the data line A storage capacitor connected to the thin film transistor, the power wiring, and one electrode of the switching thin film transistor is further formed.

The driving thin film transistor Td is connected to the switching thin film transistor and includes a semiconductor layer 410 , a gate electrode 430 , a source electrode 452 , and a drain electrode 454 .

The semiconductor layer 410 is formed on the substrate 401 and may be made of an oxide semiconductor material or polycrystalline silicon. When the semiconductor layer 410 is made of an oxide semiconductor material, a light-shielding pattern (not shown) may be formed under the semiconductor layer 410 , and the light-shielding pattern prevents light from being incident into the semiconductor layer 410 to prevent light from being incident on the semiconductor layer 410 . Prevents 401 from being deteriorated by light. Alternatively, the semiconductor layer 410 may be made of polycrystalline silicon, and in this case, both edges of the semiconductor layer 410 may be doped with impurities.

A gate insulating layer 420 made of an insulating material is formed on the semiconductor layer 410 over the entire surface of the substrate 401 . The gate insulating layer 420 may be made of an inorganic insulating material such as silicon oxide or silicon nitride.

A gate electrode 430 made of a conductive material such as metal is formed on the gate insulating layer 429 to correspond to the center of the semiconductor layer 410 . The gate electrode 430 is connected to the switching thin film transistor.

An interlayer insulating layer 440 made of an insulating material is formed on the entire surface of the substrate 401 on the gate electrode 430 . The interlayer insulating layer 440 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride, or an organic insulating material such as benzocyclobutene or photo-acryl.

The interlayer insulating layer 440 has first and second semiconductor layer contact holes 442 and 444 exposing both sides of the semiconductor layer 410 . The first and second semiconductor layer contact holes 442 and 444 are positioned on both sides of the gate electrode 430 to be spaced apart from the gate electrode 430 .

A source electrode 452 and a drain electrode 454 made of a conductive material such as metal are formed on the interlayer insulating layer 440 . The source electrode 452 and the drain electrode 454 are spaced apart from the center of the gate electrode 430 , and are formed on both sides of the semiconductor layer 410 through the first and second semiconductor layer contact holes 442 and 444 , respectively. contact The source electrode 452 is connected to a power line (not shown).

The semiconductor layer 410 , the gate electrode 430 , the source electrode 452 , and the drain electrode 454 form a driving thin film transistor Td, and the driving thin film transistor Td is a gate on the semiconductor layer 410 . It has a coplanar structure in which the electrode 430 , the source electrode 452 , and the drain electrode 454 are positioned.

Alternatively, the driving thin film transistor Td may have an inverted staggered structure in which a gate electrode is disposed under a semiconductor layer and a source electrode and a drain electrode are disposed above the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon. Meanwhile, the switching thin film transistor (not shown) may have substantially the same structure as the driving thin film transistor Td.

Meanwhile, the organic light emitting diode display 400 may include a color filter 460 that absorbs light generated by the organic light emitting diode 500 . For example, the color filter 360 may absorb red (R), green (G), blue (B), and white (W) light. In this case, red, green, and blue color filter patterns for absorbing light may be formed separately for each pixel area, and each of these color filter patterns is an organic light emitting diode (OLED) emitting light of a wavelength band to be absorbed. 500 ) may be disposed to overlap with the organic light emitting layer 530 . By adopting the color filter 460 , the organic light emitting diode display 400 may realize full-color.

For example, when the organic light emitting diode display 400 is a bottom light emitting type, a color filter 460 absorbing light may be positioned on the interlayer insulating layer 440 corresponding to the organic light emitting diode 500 . In an optional embodiment, when the organic light emitting diode display 400 is a top emission type, the color filter may be positioned above the light emitting diode 500 , that is, above the second electrode 520 . For example, the color filter 460 may be formed to a thickness of 2 to 5 μm. In this case, the organic light emitting diode 500 may be a white light emitting diode having the tandem structure shown in FIG. 4 .

Meanwhile, a protective layer 470 having a drain contact hole 472 exposing the drain electrode 454 of the driving thin film transistor Td is formed to cover the driving thin film transistor Td.

A first electrode 510 connected to the drain electrode 454 of the driving thin film transistor Td through a drain contact hole 472 is formed on the passivation layer 470 to be separated for each pixel area.

The first electrode 510 may be an anode, and may be made of a conductive material having a relatively large work function value. For example, the first electrode 510 is ITO. It may be made of a transparent conductive material such as IZO or ZnO.

Meanwhile, when the organic light emitting diode display 400 is a top-emission type, a reflective electrode or a reflective layer may be further formed under the first electrode 510 . For example, the reflective electrode or the reflective layer may be formed of any one of aluminum (Al), silver (Ag), nickel (Ni), and an aluminum-palladium-copper (APC) alloy.

A bank layer 486 covering an edge of the first electrode 510 is formed on the passivation layer 470 . The bank layer 480 exposes the center of the first electrode 510 corresponding to the pixel area.

A light emitting part 530 is formed on the first electrode 510 . For example, the light emitting unit 530 may have two or more light emitting units shown in FIG. 4 , and accordingly, the organic light emitting diode 500 may have a tandem structure.

A second electrode 520 is formed on the substrate 401 on which the light emitting part 530 is formed. The second electrode 520 is located on the entire surface of the display area and is made of a conductive material having a relatively small work function value and may be used as a cathode. For example, the second electrode 520 may be formed of any one of aluminum (Al), magnesium (Mg), and an aluminum-magnesium alloy (AlMg).

The first electrode 510 , the light emitting part 530 , and the second electrode 520 form the organic light emitting diode 500 .

An encapsulation film 490 is formed on the second electrode 520 to prevent external moisture from penetrating into the organic light emitting diode 500 . Although not shown, the encapsulation layer 490 may have a triple-layer structure in which a first inorganic layer, an organic layer, and an inorganic layer are sequentially stacked, but is not limited thereto.

Hereinafter, Examples and Comparative Examples of the present invention will be described. The following examples are only examples of the present invention, and the present invention is not limited to the following examples.

( Example )

Example One

In a vacuum chamber with a pressure of 5x10 ^-8 to 7x10 ^-8 torr, on an ITO substrate (anode), a hole injection layer, a hole transport layer (HTL1), a blue light emitting layer (blue host material (BH) and a blue fluorescent dopant material (BD, 4 wt% doping)), an electron transport layer (ETL1), an electron injection layer (LiF), and a cathode were sequentially deposited to fabricate an organic light emitting diode.

6 is an energy diagram schematically illustrating energy levels of HTL1/BH+BD/ETL1 of the fabricated organic light emitting diode. As a result of evaluating the energy level, in the manufactured organic light emitting diode, the difference between the HOMO energy level of HTL1 and the HOMO energy level of BD is 0.1 eV or less, and the difference between the LUMO energy level of HTL1 and the LUMO energy level of BH is 0.5 eV above, the difference between the LUMO energy level of ETL1 and the LUMO energy level of BD was 0.1 eV or less. In FIG. 6 , the difference between the HOMO energy level of HTL1 indicated by the dotted line and the HOMO energy level of BD is 0.1 eV or less, and the difference between the LUMO energy level of HTL1 and the LUMO energy level of BH indicated by the dotted line is 0.5 eV or more, The difference between the LUMO energy level of ETL1 and the LUMO energy level of BD indicated by the dotted line is 0.1 eV or less.

comparative example One

In a vacuum chamber with a pressure of 5x10 ^-8 to 7x10 ^-8 torr, on the ITO substrate (anode), a hole injection layer, a hole transport layer (HTL2), a blue light emitting layer (blue host material (BH) and blue fluorescent dopant material (BD, 4 wt% doping)), an electron transport layer (ETL2), an electron injection layer (LiF), and a cathode were sequentially deposited to fabricate an organic light emitting diode.

7 is an energy diagram schematically illustrating energy levels of HTL2/BH+BD/ETL2 of the fabricated organic light emitting diode. As a result of evaluating the energy level, in the manufactured organic light emitting diode, the difference between the HOMO energy level of HTL1 and the HOMO energy level of BD exceeded 0.1 eV, and the difference between the LUMO energy level of ETL1 and the LUMO energy level of BD was 0.1 eV was exceeded. In FIG. 7 , the difference between the HOMO energy level of HTL1 indicated by the dotted line and the HOMO energy level of BD exceeds 0.1 eV, and the difference between the LUMO energy level of ETL1 and the LUMO energy level of BD indicated by the dotted line exceeds 0.1 eV. indicates.

Materials used in Example 1 and Comparative Example 1 and their physical properties are as follows.

Experimental example 1: Evaluation of organic light emitting diode characteristics

The driving characteristics of each of the organic light emitting diodes manufactured in Example 1 and Comparative Example 1 were evaluated.

The voltage-current density, luminance-current efficiency, luminance-external quantum efficiency (EQE), and lifetime characteristics measured for the organic light emitting diodes of Example 1 and Comparative Example 1 are described in Table 2 below.

division Voltage
(V) Voltage-Current Density
(Cd/A) Luminance - External Quantum Efficiency
(EQE) life span
(hr) Example 1 3.7 8.0 8.1 50 Comparative Example 1 4.4 6.3 6.5 25

In Comparative Example 1, the difference in HOMO energy gap between HTL2 and BH is larger than in Example 1 due to violation of the (e) condition, (i) condition and (d) condition described above, and the T ₁ energy (triplet energy) is low. Referring to the physical property values shown in Table 1, in the case of the HTL2 material used in Comparative Example 1, T _{1 , HTL} = 2.52 eV < 2.8 eV. In addition, in the case of the ETL2 material used in Comparative Example 1, T _{1 , ETL} = 2.2 eV < 2.6 eV, which is greater than the triplet energy of the blue light emitting layer host among the conditions presented in (car) (the first half relationship is satisfied), but the triplet Materials that do not reach the energy range (the latter relationship is not satisfied). _{As in Comparative Example 1, in the case of a material smaller than the energy range of T 1 , HTL} and T _{1 , ETL} presented in the (secondary) condition, the triplet energy of the blue light emitting layer host material and the triplet of each of the hole transport layer material and the electron transport layer material The difference between the energies is not large. In the case of FIG. 7 , compared to Example 1, Comparative Example 1 does not show a significant difference from the triplet energy of the blue light emitting layer host.

As such, the (difference) condition means that a difference between the triplet energy of the blue light emitting layer host and the triplet energy of each of the hole transport layer material and the electron transport layer material must exist at a certain level or more.

Referring to the physical property values shown in Table 1, in FIG. 6 for Example 1, T _{1 , HTL} = 2.82 eV, T _{1 , ETL} = 2.67 eV Then, the range of triplet energy of the (secondary) condition is satisfied, A difference between triplet energy and triplet energy of each of the hole transport layer material and the electron transport layer material exists at a certain level or more.

The organic light emitting diode of Comparative Example 1 violates the condition (E) (the difference in energy between the two energy exceeds 0.1 eV in Comparative Example 1), so it is difficult to inject holes into the blue light emitting layer, so a large driving voltage is required, and the condition (i) and (difference) ) conditions (in Comparative Example 1, the difference in energy between the two exceeds 0.1 eV, T _{1 , HTL} = 2.52 eV < 2.8 eV, T _{1 , ETL} = 2.2 eV < 2.6 eV), so that excitons generated are confined in the blue light emitting layer difficult. In Comparative Example 1, an exciton may generate an impurity by causing an addition reaction with the charge transport layer around the blue light emitting layer. The generated impurities may act as charge traps injected into both sides of the blue light emitting layer. As a result, the driving characteristics of the organic light emitting diode are deteriorated, and the lifespan of the organic light emitting diode is adversely affected.

From the results of Table 2, it can be seen that Comparative Example 1 has inferior driving characteristics compared to Example 1, and that the lifetime of the device is also short.

In the above, although the embodiment of the present invention has been mainly described, various changes or modifications may be made at the level of those skilled in the art. Accordingly, it will be understood that such changes and modifications are included within the scope of the present invention without departing from the scope of the present invention.

100, 200, 300, 500: organic light emitting diode
110, 210, 310, 410, 510: first electrode
120, 220, 320, 420, 520: second electrode
140, 240, 530: light emitting part
141, 241, 341, 351: hole transport layer
142, 242, 342, 352: blue light emitting layer
144, 244, 344, 354: electron transport layer
243: hole injection layer
245: electron injection layer
340: first light emitting unit
350: second light emitting unit
360: charge generation layer
362: N-type charge generation layer
364: P-type charge generation layer
400: organic light emitting display device

Claims (15)

a first electrode;
a light emitting part positioned on the first electrode; and
a second electrode positioned on the light emitting part; and
The light emitting part comprises the hole transport layer, the blue light emitting layer and the electron transport layer so that the hole transport layer, the blue light emitting layer and the electron transport layer in contact with the hole transport layer are sequentially positioned from the first electrode,
The blue light emitting layer includes a blue host material and a blue fluorescent dopant material,
The hole transport layer includes a hole transport layer material,
The electron transport layer includes an electron transport layer material, the electron transport layer material
Group consisting of oxadiazole, triazole, phenanthroline, benzoxazole, benzothiazole, benzimidazole, triazine, pyrimidine series and combinations thereof It contains one selected from
a lowest unoccupied molecular orbital (LUMO) energy level of the blue fluorescent dopant material is above the LUMO energy level of the blue host material;
a Highest Occupied Molecular Orbital (HOMO) energy level of the blue fluorescent dopant material is above the HOMO energy level of the blue host material,
The magnitude of the singlet energy of the blue fluorescent dopant material is smaller than the singlet energy of the blue host material,
the HOMO energy level of the hole transport layer material is above the HOMO energy level of the blue host material,
The LUMO energy level of the hole transport layer material is above the LUMO energy level of the blue host material,
The LUMO energy level of the hole transport layer material is above the LUMO energy level of the blue fluorescent dopant material,
the LUMO energy level of the electron transport layer material is above the LUMO energy level of the blue host material,
The LUMO energy level of the electron transport layer material is higher than the LUMO energy level of the blue fluorescent dopant material, and the difference between the two energies is 0.1 eV or less,
T _1,HTL , T _1,ETL and When T _1,BH represents each triplet energy of the hole transport layer material, the electron transport layer material, and the blue host material, T _1,BH < T _1,HTL and T _{1,BH between the three triplet energies.} < T _1,ETL exists and has a range of 2.6 < T _{1,ETL < 2.8,}
The hole transport layer material includes a tertiary amine-based material,
The blue host material includes an anthracene-based material,
The blue fluorescent dopant material comprises a pyrene amine derivative material.
organic light emitting diode.
According to claim 1,
The electron transport layer material is Alq3, 2-biphenyl-4-yl-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (2-biphenyl-4-yl-5-(4) -tbutylphenyl)-1,3,4-oxadiazole, PBD), spiro-PBD, lithium quinolate (Liq), 2-[4-(9,10-di-2-naphthalenyl-2-anthra) Cenyl)phenyl]-1-phenyl-1H-benzimidazole (2-[4-(9,10-Di-2-naphthalenyl-2-anthracenyl)phenyl]-1-phenyl-1Hbenzimidazol), 3-(biphenyl -4-yl)-5-(4-tertbutylphenyl)-4-phenyl-4H-1,2,4-triazole(3-(biphenyl-4-yl)-5-(4-tertbutylphenyl)-4 -phenyl-4H-1,2,4-triazole, TAZ), 4,7-diphenyl-1,10-phenanthroline (4,7-diphenyl-1,10-phenanthroline, Bphen), tris (phenylquinoc) saline) (tris(phenylquinoxaline, TPQ), 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene (1,3,5-Tri[(3-pyridyl)-phen-3 -yl]benzene, TmPyPB), 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (1,3,5-tris(N-phenylbenzimiazole-2-yl)benzene, TPBI) and comprising one selected from the group consisting of combinations thereof
organic light emitting diode.
According to claim 1,
The HOMO energy level of the hole transport layer material is higher than the HOMO energy level of the blue fluorescent dopant material, and the difference between the two energies is 0.1 eV or less.
organic light emitting diode.
According to claim 1,
The difference between the LUMO energy level of the hole transport layer material and the LUMO energy level of the blue host material is 0.5 eV or more
organic light emitting diode.
According to claim 1,
The triplet energy of the hole transport layer material is 2.8 < T _1,HTL <3.0 person
organic light emitting diode.
delete According to claim 1,
The hole transport layer material is N-[1,1'-biphenyl]-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine containing (N-[1,1'-biphenyl]-4-yl-9,9-diMethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine)
organic light emitting diode.
According to claim 1,
The blue light emitting layer includes the blue fluorescent dopant material in an amount of 1 to 5 wt%
organic light emitting diode.
According to claim 1,
The light emitting unit is a first light emitting unit,
Further comprising at least one additional light emitting unit including a second light emitting unit between the first electrode and the second electrode
organic light emitting diode.
10. The method of claim 9,
The first light-emitting unit emits blue light, and the second light-emitting unit emits green (G), yellow-green (YG), yellow (Y), or orange having a longer wavelength than blue.
organic light emitting diode.
10. The method of claim 9,
and a charge generation layer positioned between the first light emitting part and the second light emitting part.
organic light emitting diode.
12. The method of claim 11,
The charge generation layer includes an N-type charge generation layer and a P-type charge generation layer
organic light emitting diode.
10. The method of claim 9,
The organic light emitting diode is a white organic light emitting diode in which white light is realized by a mixing effect of light emitted from the first light emitting unit and the second light emitting unit.
organic light emitting diode.
Board;
The organic light emitting diode according to any one of claims 1 to 5 and 7 to 13 positioned on the substrate; and
a driving element positioned between the substrate and the organic light emitting diode and connected to the first electrode;
An organic light emitting display device comprising a.
15. The method of claim 14,
Further comprising a color filter positioned between the substrate and the first electrode or on the organic light emitting diode
organic light emitting display device.

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