KR20230053562A - Organic light emitting device - Google Patents

Abstract

The present invention provides an organic light emitting element comprising: a first light emitting part comprising a first light emitting layer and is between a first electrode and a second electrode; a second light emitting part comprising a second light emitting layer and is on top of the first light emitting part; and a third light emitting part comprising a third light emitting layer and is on top of the second light emitting part, wherein a light emitting position of the first light emitting layer is in a range of 270-330 nm from the second electrode, and a light emitting position of the third light emitting layer is in a range of 20-80 nm from the second electrode. Therefore, the present invention is capable of having an effect of improving an efficiency of red, green, and blue.

Description

Organic light emitting device {ORGANIC LIGHT EMITTING DEVICE}

The present invention relates to an organic light emitting device, and more particularly, to a white organic light emitting device capable of improving light emitting efficiency and color viewing angle or color reproducibility.

Recently, as we enter the information age, the display field that visually expresses electrical information signals has developed rapidly. device) is being developed.

Specific examples of such a flat panel display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an organic light emitting display device. (Organic Light Emitting Device: OLED) etc. are mentioned.

In particular, the organic light emitting display device is a self-light emitting device and has advantages of a fast response speed, high luminous efficiency, luminance, and viewing angle compared to other flat panel display devices.

An organic light emitting device is composed of an organic light emitting layer between two electrodes. Electrons and holes are respectively injected from the two electrodes into the organic light emitting layer to generate excitons according to the combination of electrons and holes. And, it is a device using the principle of generating light when the generated excitons fall from an excited state to a ground state.

[White organic light emitting device] (Patent Application No. 10-2009-0092596)

The organic light emitting diode implements full color in sub-pixels emitting red (R), green (G), and blue (B). The sub-pixels emitting red (R), green (G), and blue (B) may express color gamut with color coordinates of red (R), green (G), and blue (B), respectively. The color coordinates are highly dependent on the material of the light emitting layer. In particular, in the case of phosphorescent materials, since triplet excitons contribute to light emission, a device with higher efficiency than fluorescent materials can be realized.

However, efforts are being made to improve color coordinates and color gamut of organic light emitting diodes according to consumer demand for excellent image quality.

As one method, there is a method of using a light emitting layer as a single layer. In this method, a white organic light emitting diode can be manufactured by using a single material or doping two or more materials. For example, there is a method of using red and green dopants in a blue host or adding red, green and blue dopants to a host material having a large band gap energy. However, this method has problems in that energy transfer to the dopant is incomplete and it is difficult to control the balance of white color.

In addition, there is a limit to the components of the dopant included in the light emitting layer due to the characteristics of the dopant itself. In addition, when each light emitting layer is mixed, the focus is on realizing white light, so that wavelength characteristics having peak wavelength values at wavelengths other than red, green, and blue are exhibited. Therefore, there is a problem in that luminous efficiency of red, green, and blue is lowered due to an undesirable peak wavelength value.

Alternatively, a structure that emits white light may be obtained by stacking two light emitting layers having a complementary color relationship. However, in this structure, when white light passes through the color filter, a difference occurs between a wavelength region corresponding to a peak wavelength of each light emitting layer and a transmission region of the color filter. Therefore, there is a problem in implementing a desired color gamut due to a narrow range of colors that can be expressed.

And, when a blue light emitting layer and a yellow-green light emitting layer are composed of two light emitting layers, the blue light emitting layer and the yellow-green light emitting layer and the yellow-green light emitting layer are formed according to the difference in cavity peak. The light emitting layer has a different rate of spectral change according to a viewing angle. Therefore, in order to adjust the spectral change rate according to the viewing angle of the blue light emitting layer and the yellow-green light emitting layer, the cavity peak of the yellow-green light emitting layer is adjusted to a position that is displaced from the desired position. Therefore, a problem arises in that the efficiency of red, green, and blue is reduced.

Therefore, the inventors of the present invention recognize the above-mentioned problems, and improve the efficiency of red, green, and blue by considering the spectral change rate of the light emitting layers and the cavity peak, and the color viewing angle or color viewing angle according to the viewing angle. Several experiments were conducted to improve the color gamut.

Therefore, through various experiments, white organic light emitting with a new structure that can improve the efficiency of red, green, and blue, and improve the luminous efficiency of the light emitting layer and the color viewing angle or color gamut according to the viewing angle. device was invented.

The problem to be solved according to an embodiment of the present invention is white organic light emitting that can improve the efficiency of red, green, and blue, the luminous efficiency of the light emitting layer, and the panel efficiency by optimizing the light emitting position of the light emitting layer. It is to provide a small.

An object to be solved according to an embodiment of the present invention is to provide a white organic light emitting device capable of improving device efficiency and color viewing angle or color gamut according to a viewing angle by constituting at least two light emitting layers emitting the same color. .

Solved problems according to embodiments of the present invention are not limited to the above-mentioned problems, and other problems not mentioned above will be clearly understood by those skilled in the art from the description below.

The present invention includes a first light emitting layer, the first light emitting portion between the first electrode and the second electrode; a second light emitting unit including a second light emitting layer and disposed above the first light emitting unit; and a third light emitting layer, a third light emitting portion above the second light emitting portion, wherein a light emitting position of the first light emitting layer is in a range of 270 nm to 330 nm from the second electrode, and a light emitting position of the third light emitting layer is An organic light emitting device in the range of 20 nm to 80 nm from the second electrode is provided.

A light emitting position of the second light emitting layer may be in a range of 150 nm to 200 nm from the second electrode.

A location of the first electrode may be in a range of 500 nm to 600 nm from the second electrode.

The present invention includes a first light emitting layer, the first light emitting portion between the first electrode and the second electrode; a second light emitting unit including a second light emitting layer and disposed above the first light emitting unit; and a third light emitting layer, a third light emitting portion above the second light emitting portion, wherein a light emitting position of the first light emitting layer is in a range of 100 nm to 150 nm from the first electrode, and a light emitting position of the third light emitting layer is Provided is an organic light emitting device in the range of 370 nm to 410 nm from the first electrode.

A light emitting position of the second light emitting layer may be in a range of 240 nm to 280 nm from the first electrode.

A location of the second electrode may be in a range of 500 nm to 600 nm from the first electrode.

Two light emitting layers of the first light emitting layer, the second light emitting layer, and the third light emitting layer may emit the same color, and the light emitting layers emitting the same color may be disposed adjacent to each other.

The two light emitting layers may be the first light emitting layer and the second light emitting layer.

The first light emitting layer and the second light emitting layer may be one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer.

Peak wavelengths (λmax) of the first light emitting layer and the second light emitting layer may be in the range of 440 nm to 480 nm.

The light emitting layer emitting a different color from the same color may be one of a yellow-green light emitting layer, a green light emitting layer, a red light emitting layer and a green light emitting layer, a yellow light emitting layer and a red light emitting layer, or a yellow-green light emitting layer and a red light emitting layer, or a combination thereof. can

The light emitting layer emitting a different color from the same color is the third light emitting layer, and the peak wavelength (λmax) of the third light emitting layer may be in the range of 510 nm to 580 nm or 510 nm to 650 nm.

The two light emitting layers may be configured closer to the first electrode than to the second electrode.

A color viewing angle (Δu'v') of light emitted from the organic light emitting device may be 0.016 or less at a 60° viewing angle.

A first charge generation layer may be further provided between the first light emitting unit and the second light emitting unit, and a second charge generation layer may be further provided between the second light emitting unit and the third light emitting unit.

Other embodiment specifics are included in the detailed description and drawings.

By optimizing the light emitting position of the light emitting layer according to an embodiment of the present invention, there is an effect of improving red, green, and blue efficiency.

In addition, by optimizing the light emitting position of the light emitting layer, there is an effect of improving light emitting efficiency or panel efficiency of the light emitting layer, and color viewing angle or color reproducibility.

By constituting two light emitting layers emitting the same color adjacently according to an embodiment of the present invention, there is an effect of improving the light emitting intensity of the light emitting layer.

In addition, since the light emitting intensity of the light emitting layer increases, light emitting efficiency and color reproduction rate are improved, and power consumption is reduced due to the improved efficiency, so there is an effect that can be applied to a large-area TV.

In addition, by configuring two light emitting layers emitting the same color, there is an effect that device efficiency can be improved, and a color viewing angle or color gamut according to a viewing angle can be improved.

In addition, by configuring two light emitting layers emitting the same color in consideration of the spectral change rate of the light emitting layers and the cavity peak, since the difference in the spectral change rate of the light emitting layers can be made almost similar, the color viewing angle or color gamut according to the viewing angle can be improved. there is.

In addition, since the difference in spectral change rates of the light emitting layers can be made substantially similar, the cavity peak of the light emitting layers can be located in the light emitting region. Therefore, by locating the cavity peak of the light emitting layers in the light emitting region, the peak wavelength of the light emitting layers is positioned at a desired position, thereby improving light emitting efficiency and device efficiency, and improving color viewing angle or color gamut according to the viewing angle.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Since the content of the invention described in the problem to be solved, the means for solving the problem, and the effect above does not specify the essential features of the claim, the scope of the claim is not limited by the matters described in the content of the invention.

1 is a schematic cross-sectional view showing a white organic light emitting device according to a first embodiment of the present invention.
2 is a diagram showing the spectrum of the light emitting layer according to the first embodiment of the present invention.
3 is a diagram showing EL spectra according to a comparative example and a first embodiment of the present invention.
4 is a graph showing a spectrum change rate according to a viewing angle according to a first embodiment of the present invention.
5 is a diagram showing color coordinates according to a comparative example and a first embodiment of the present invention.
6 is a diagram showing color viewing angles according to a comparative example and a first embodiment of the present invention.
7 is a diagram showing EL spectra according to Comparative Example 1 and the first embodiment of the present invention.
8 is a view showing color viewing angles according to Comparative Example 1 and the first embodiment of the present invention.
9 is a schematic cross-sectional view showing a white organic light emitting device according to a second embodiment of the present invention.
10 is a view showing a light emitting position of an organic light emitting device according to a second embodiment of the present invention.
11 is a diagram showing an EL spectrum according to a second embodiment of the present invention.
12 is a diagram showing a color viewing angle according to a second embodiment of the present invention.
13 is a schematic cross-sectional view showing a white organic light emitting diode according to a third embodiment of the present invention.
14 is a diagram showing a light emitting position of an organic light emitting device according to a third embodiment of the present invention.
15 is a diagram showing an EL spectrum according to a third embodiment of the present invention.
16 is a diagram showing a color viewing angle according to a third embodiment of the present invention.
17 is a diagram illustrating an organic light emitting display device according to an exemplary embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only the present embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the details shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

In interpreting the components, even if there is no separate explicit description, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless 'directly' is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal precedence relationship is described in terms of 'after', 'following', 'next to', 'before', etc. It can also include non-continuous cases unless is used.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship. may be

Hereinafter, looking at the embodiments of the present invention in detail through the accompanying drawings and examples are as follows.

1 is a schematic cross-sectional view showing a white organic light emitting device according to a first embodiment of the present invention.

The white organic light emitting device 100 shown in FIG. 1 includes first and second electrodes 102 and 104 on a substrate 101, and a first light emitting part 110 between the first and second electrodes 102 and 104, and a second A light emitting unit 120 and a third light emitting unit 130 are provided.

The first electrode 102 is an anode supplying holes and may be formed of gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), or an alloy thereof, , but is not necessarily limited thereto.

The second electrode 104 is a cathode supplying electrons and may be formed of a transparent conductive material such as TCO (Transparent Conductive Oxide) such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IGZO (Indium Gallium Zinc Oxide), or the like. may be, but is not necessarily limited thereto. Alternatively, the second electrode 104 may be formed of metallic materials such as gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), or an alloy thereof, It is not necessarily limited to this. Alternatively, the second electrode 104 is TCO (Transparent Conductive Oxide), ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IGZO (Indium Gallium Zinc Oxide) and metallic materials gold (Au), silver (Ag) , aluminum (Al), molybdenum (Mo), may be formed of two layers such as magnesium (Mg), but is not necessarily limited thereto.

The first electrode 102 and the second electrode 104 may be referred to as an anode or a cathode, respectively.

The first electrode 102 may be a reflective electrode, and the second electrode 104 may be a transflective electrode.

The first light emitting part 110 includes a first hole transporting layer (HTL) 112, a first emitting layer (EML) 114 and a first electron transporting layer ( It may include an Electron Transporting Layer (ETL) 116.

Although not shown in the figure, a hole injecting layer (HIL) may be additionally formed on the first electrode 102 . The hole injection layer HIL serves to smoothly inject holes from the first electrode 102 . The first hole transport layer (HTL) 112 supplies holes from the hole injection layer (HIL) to the first light emitting layer (EML) 114 . The first electron transport layer (ETL) 116 supplies electrons from the first charge generation layer (CGL) 140 to the first light emitting layer (EML) 114 .

The hole injection layer (HIL) is made of MTDATA (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine), CuPc (copper phthalocyanine), or PEDOT/PSS (poly(3,4-ethylenedioxythiphene, polystyrene sulfonate), etc. It can be made, but is not necessarily limited thereto.

In the first light emitting layer (EML) 114, holes supplied through the first hole transport layer (HTL) 112 and electrons supplied through the first electron transport layer (ETL) 116 recombine. so light is generated.

The first hole transport layer (HTL) 112 may be formed by applying two or more layers or two or more materials. The first hole transport layer (HTL) 112 is NPD (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 Spiro-TAD (2,2'7,7'tetrakis(N,N-diphenylamino)-9,9' -spirofluorene), but may be made of one or more selected from the group consisting of, but is not limited thereto.

The first electron transport layer (ETL) 116 may be formed by applying two or more layers or two or more materials. The first electron transport layer (ETL) 116 is PBD (2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), TAZ (3-(4-biphenyl) -4-phenyl-5-tert-butylphenyl-1,2,4-triazole), BAlq (Bis(2-methyl-8-quinolinolate)-4-(phenylphenolato)aluminium), Liq(8-hydroxyquinolinolato-lithium), It may consist of at least one selected from the group consisting of TPBi(2,2', 2'-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole), but is not limited thereto.

A hole blocking layer (HBL) may be additionally formed on the first light emitting layer (EML) 114 . The hole blocking layer (HBL) prevents the holes injected into the first light emitting layer (EML) 114 from passing over to the first electron transport layer (ETL) 116, thereby forming the first light emitting layer (EML) 114 The luminous efficiency of the first light emitting layer (EML) 114 may be improved by improving the coupling of electrons and holes in the . The first electron transport layer (ETL) 116 and the hole blocking layer (HBL) may be configured as one layer.

An electron blocking layer (EBL) may be additionally formed under the first light emitting layer (EML) 114 . The electron blocking layer (EBL) prevents electrons injected into the first light emitting layer (EML) 114 from passing over to the first hole transport layer (HTL) 112, thereby preventing the first light emitting layer (EML) 114 The luminous efficiency of the first light emitting layer (EML) 114 may be improved by improving the coupling of electrons and holes in the . The first hole transport layer (HTL) 112 and the electron blocking layer (EBL) may be configured as one layer.

The first light emitting layer (EML) 114 of the first light emitting part 110 may include a blue light emitting layer. The first light emitting layer (EML) 114 may be formed of a deep blue light emitting layer or a sky blue light emitting layer in addition to a blue light emitting layer. Since the deep blue light emitting layer is located in a shorter wavelength region than the blue light emitting layer, it may be advantageous to improve color reproducibility and luminance.

The peak wavelength λmax of the first light emitting layer (EML) 114 may be in the range of 440 nm to 480 nm. Here, the peak wavelength may be a light emitting region.

Alternatively, the first light emitting layer (EML) 114 may include a blue light emitting layer and an auxiliary light emitting layer capable of emitting light of a different color. The auxiliary light emitting layer may be composed of one of a yellow-green light emitting layer, a red light emitting layer, and a green light emitting layer, or a combination thereof. When the auxiliary light emitting layer is further formed, the luminous efficiency of the green light emitting layer or the red light emitting layer may be further improved. When configuring the first light emitting layer (EML) 114 including the auxiliary light emitting layer, the yellow-green light emitting layer, the red light emitting layer, or the green light emitting layer is the first light emitting layer (EML) It is also possible to construct above or below (114).

In addition, as the auxiliary light emitting layer, a yellow-green or red light emitting layer or a green light emitting layer may be configured identically or differently above and below the first light emitting layer (EML) 114 . there is. The location or number of light emitting layers can be selectively arranged according to the configuration and characteristics of the device, but is not necessarily limited thereto.

The peak wavelength λmax of the first light emitting layer (EML) 114 including the yellow-green light emitting layer as the auxiliary light emitting layer may be in the range of 440 nm to 590 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength λmax of the first light emitting layer (EML) 114 including the red light emitting layer as the auxiliary light emitting layer may be in the range of 440 nm to 650 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength (λmax) of the first light emitting layer (EML) 114 including the green light emitting layer, which is the auxiliary light emitting layer, may be in the range of 440 nm to 570 nm. Here, the peak wavelength may be a light emitting region.

The host of the first light emitting layer (EML) 114 may be composed of a single material or a mixed host composed of mixed materials. For example, Alq ₃ (tris(8-hydroxy-quinolino)aluminum), ADN (9,10-di(naphtha-2-yl)anthracene), BSBF (2-(9,9-spirofluoren-2-yl) -9,9-spirofluorene) materials or a mixture of two or more may be selected, but is not necessarily limited thereto.

Also, a dopant of the first light emitting layer (EML) 114 may be made of pyrene. More specifically, it may consist of a pyrene-based compound in which an aryl amine-based compound is substituted, but is not necessarily limited thereto.

The second light emitting unit 120 includes a second hole transporting layer (HTL) 122, a second emitting layer (EML) 124, and a second electron transporting layer (ETL) 126 ) can be made including.

Although not shown in the drawing, the second light emitting part 120 may additionally include an electron injection layer (EIL) on the second electron transport layer (ETL) 126 . In addition, the second light emitting unit 120 may further include a hole injecting layer (HIL).

The second hole transport layer (HTL) 122 may be made of the same material as the first hole transport layer (HTL) 112, but is not necessarily limited thereto.

The second hole transport layer (HTL) 122 may be formed by applying two or more layers or two or more materials.

The second electron transport layer (ETL) 126 may be made of the same material as the first electron transport layer (ETL) 116, but is not necessarily limited thereto.

The second electron transport layer (ETL) 126 may be formed by applying two or more layers or two or more materials.

A hole blocking layer (HBL) may be additionally formed on the second light emitting layer (EML) 124 . The hole blocking layer (HBL) prevents holes injected into the second light emitting layer (EML) 124 from passing over to the second electron transport layer (ETL) 126, thereby forming the second light emitting layer (EML) 124 The luminous efficiency of the second light emitting layer (EML) 124 may be improved by improving the coupling of electrons and holes in the . The second electron transport layer (ETL) 126 and the hole blocking layer (HBL) may be configured as one layer.

An electron blocking layer (EBL) may be additionally formed under the second light emitting layer (EML) 124 . The electron blocking layer (EBL) prevents electrons injected into the second light emitting layer (EML) 124 from passing over to the second hole transport layer (HTL) 122, thereby preventing the second light emitting layer (EML) 124 The luminous efficiency of the second light emitting layer (EML) 124 may be improved by improving the coupling of electrons and holes in the . The second hole transport layer (HTL) 122 and the electron blocking layer (EBL) may be configured as one layer.

The second light emitting layer (EML) 124 of the second light emitting part 120 may include a blue light emitting layer. The second light emitting layer (EML) 124 may be formed of a deep blue light emitting layer or a sky blue light emitting layer in addition to a blue light emitting layer. Since the deep blue light emitting layer is located in a shorter wavelength region than the blue light emitting layer, it may be advantageous to improve color reproducibility and luminance.

The peak wavelength λmax of the second light emitting layer (EML) 124 may be in the range of 440 nm to 480 nm. Here, the peak wavelength may be a light emitting region.

Alternatively, the second light emitting layer (EML) 124 may include a blue light emitting layer and an auxiliary light emitting layer capable of emitting light of a different color. The auxiliary light emitting layer may be composed of one of a yellow-green light emitting layer, a red light emitting layer, and a green light emitting layer, or a combination thereof. When the auxiliary light emitting layer is further formed, the luminous efficiency of the green light emitting layer or the red light emitting layer may be further improved. When configuring the second light emitting layer (EML) 124 including the auxiliary light emitting layer, the yellow-green light emitting layer, the red light emitting layer, or the green light emitting layer is the second light emitting layer (EML). It is also possible to construct above or below (124).

In addition, as the auxiliary light emitting layer, a yellow-green or red light emitting layer or a green light emitting layer may be configured identically or differently above and below the second light emitting layer (EML) 124 . there is. The location or number of light emitting layers can be selectively arranged according to the configuration and characteristics of the device, but is not necessarily limited thereto.

The peak wavelength λmax of the second light emitting layer (EML) 124 including the yellow-green light emitting layer as the auxiliary light emitting layer may be in the range of 440 nm to 590 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength λmax of the second light emitting layer (EML) 124 including the red light emitting layer as the auxiliary light emitting layer may be in the range of 440 nm to 650 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength λmax of the second light emitting layer (EML) 124 including the green light emitting layer, which is the auxiliary light emitting layer, may be in the range of 440 nm to 570 nm. Here, the peak wavelength may be a light emitting region.

The second light emitting layer (EML) 124 may be made of the same material as the first light emitting layer (EML) 114, but is not necessarily limited thereto.

The host of the second light emitting layer (EML) 124 may be composed of a single material or a mixed host composed of mixed materials. For example, Alq ₃ (tris(8-hydroxy-quinolino)aluminum), ADN(9,10-di(naphtha-2-yl)anthracene), BSBF(2-(9,9-spirofluoren- 2-yl) -9,9-spirofluorene) may be selected from materials or a mixture of two or more materials may be selected, but is not necessarily limited thereto.

Also, a dopant of the second light emitting layer (EML) 124 may be made of pyrene. More specifically, it may consist of a pyrene-based compound in which an aryl amine-based compound is substituted, but is not necessarily limited thereto.

A first charge generation layer (CGL) 140 may be further formed between the first light emitting part 110 and the second light emitting part 120 . The first charge generating layer (CGL) 140 adjusts the charge balance between the first light emitting part 110 and the second light emitting part 120 . The first charge generating layer 140 may include an N-type charge generating layer (N-CGL) and a P-type charge generating layer (P-CGL).

The N-type charge generation layer (N-CGL) 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 necessarily limited thereto.

The P-type charge generating layer (P-CGL) may be formed of an organic layer including a P-type dopant, but is not necessarily limited thereto.

Also, the first charge generating layer (CGL) 140 may be formed as a single layer.

The third light emitting part 130 includes a third electron transporting layer (ETL) 136, a third emitting layer (EML) 134, and a third hole transporting layer under the second electrode 104. (HTL; Hole Transporting Layer) 132 may be included.

Although not shown, the third light emitting part 130 may further include an electron injection layer (EIL) on the third electron transport layer (ETL) 136 . In addition, it may be configured to further include a hole injecting layer (HIL).

The third hole transport layer (HTL) 132 is TPD (N, N'-bis (3-methylphenyl) -N, N'-bis (phenyl) -benzidine) or NPB (N, N'-bis (naphthalen- 1-yl) -N,N'-bis(phenyl)-benzidine), etc., but is not necessarily limited thereto.

The third hole transport layer (HTL) 132 may be formed by applying two or more layers or two or more materials.

The third electron transport layer (ETL) 136 may be made of oxadiazole, triazole, phenanthroline, benzoxazole, or benzthiazole. It is not necessarily limited to this.

The third electron transport layer (ETL) 136 may be formed by applying two or more layers or two or more materials.

A hole blocking layer (HBL) may be additionally formed on the third light emitting layer (EML) 134 . The hole blocking layer (HBL) prevents holes injected into the first light emitting layer (EML) 134 from passing over to the third electron transport layer (ETL) 136, thereby preventing the third light emitting layer (EML) 134 The luminous efficiency of the third light emitting layer (EML) 134 may be improved by improving the coupling of electrons and holes in the . The third electron transport layer (ETL) 136 and the hole blocking layer (HBL) may be configured as one layer.

An electron blocking layer (EBL) may be additionally formed under the third light emitting layer (EML) 134 . The electron blocking layer (EBL) prevents electrons injected into the third light emitting layer (EML) 134 from passing over to the third hole transport layer (HTL) 132, thereby preventing the third light emitting layer (EML) 134 The luminous efficiency of the third light emitting layer (EML) 134 may be improved by improving the coupling of electrons and holes in the . The third hole transport layer (HTL) 132 and the electron blocking layer (EBL) may be configured as one layer.

A second charge generation layer (CGL) 150 may be further formed between the second light emitting part 120 and the third light emitting part 130 . The second charge generating layer 150 adjusts charge balance between the second light emitting part 120 and the third light emitting part 130 . The second charge generation layer (CGL) 150 may include an N-type charge generation layer (N-CGL) and a P-type charge generation layer (P-CGL).

The N-type charge generating layer (N-CGL) serves to inject electrons into the second light emitting part 120, and the P-type charge generating layer (P-CGL) serves to inject electrons into the third light emitting part 130. It serves to inject holes.

The N-type charge generation layer (N-CGL) 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 necessarily limited thereto.

The P-type charge generating layer (P-CGL) may be formed of an organic layer including a P-type dopant, but is not necessarily limited thereto. The first charge generating layer (CGL) 140 is made of the same material as the N-type charge generating layer (N-CGL) of the second charge generating layer (CGL) 150 and the P-type charge generating layer (P-CGL). It may consist of, but is not necessarily limited thereto.

Also, the second charge generating layer (CGL) 150 may be formed of a single layer.

The third light emitting layer (EML) 134 of the third light emitting part 130 is a yellow-green light emitting layer, a green light emitting layer, or a yellow light emitting layer and a red light emitting layer, Alternatively, it may be composed of one of a red light emitting layer and a green light emitting layer, or a yellow-green light emitting layer and a red light emitting layer, or a combination thereof.

The host of the third light emitting layer (EML) 134 may be composed of a single material or a mixed host composed of mixed materials. For example, CBP (4,4'-bis(carbazol-9-yl)biphenyl), spiro-CBP(2,2',7,7'-tetrakis(carbazol-9-yl)-9,9'- spirobifluorene) and TcTa (4,4',4'-tris(carbazoyl-9-yl)triphenylamine), but is not necessarily limited thereto.

The dopant of the third light emitting layer (EML) 134 may be made of an iridium-based compound, but is not necessarily limited thereto.

The white organic light emitting device according to the exemplary embodiment of the present invention has been described in terms of a bottom emission method, but it is also possible to apply a top emission method or a dual emission method. In the top emission method or the positive emission method, the overall thickness of the device or the position of the light emitting layers may vary depending on the characteristics of the device.

In addition, although not shown, in an organic light emitting display device including an organic light emitting element according to an embodiment of the present invention, a gate line and a data line defining each pixel area crossing each other on a substrate extend in parallel with any one of them. A power wiring is positioned, and a switching thin film transistor connected to the gate wiring and the data wiring and a driving thin film transistor connected to the switching thin film transistor are positioned in each pixel area. A driving thin film transistor is connected to the first electrode 102 .

In the present invention, the first light emitting layer (EML) 114 and the second light emitting layer (EML) are used to improve efficiency or luminous efficiency of red, green, and blue, and color viewing angle or color gamut. 124 and the light emitting position of the light emitting layer constituting the third light emitting layer (EML) 134 needs to be optimized. This will be described with reference to FIG. 2 .

FIG. 2 is a view showing a light emitting position of the white organic light emitting device shown in FIG. 1 .

In FIG. 2, the horizontal axis represents the wavelength region of light, and the vertical axis represents the thickness of the organic layers. As described above, the organic layers refer to layers constituting the first light emitting unit 110 , the second light emitting unit 120 , and the third light emitting unit 130 . In FIG. 2 , thicknesses of organic layers constituting the first light emitting unit 110 , the second light emitting unit 120 , and the third light emitting unit 130 are not shown.

As shown in FIG. 2 , the first light emitting layer (EML) 114 constituting the first light emitting part 110 and the second light emitting layer (EML) 124 constituting the second light emitting part 120 are blue (Blue). ), and it can be seen that the peak wavelength (λmax) of the blue light emitting layer is 440 nm to 480 nm. Regions corresponding to peak wavelengths (λmax) of the first light emitting layer (EML) 114 and the second light emitting layer (EML) 124 are indicated by “B” in FIG. 2 .

And, the third light emitting layer (EML) 134 constituting the third light emitting part 130 is a yellow-green light emitting layer, and the peak wavelength of the yellow-green light emitting layer (λmax) ) is 540 nm to 575 nm. A region corresponding to the peak wavelength (λmax) of the third light emitting layer (EML) 134 is indicated as “YG” in FIG. 2 .

Therefore, the contour line ( The maximum efficiency can be obtained in the white area of the contour map. Therefore, it can be seen that the light emitting layer can achieve maximum efficiency by setting the emission position of the light emitting layers of the present invention to correspond to the peak wavelength of the light emitting layers. In addition, since the luminous efficiency of the light emitting layer is increased, panel efficiency, color reproducibility, and color viewing angle can be improved.

Here, the peak wavelength (λmax) refers to the maximum wavelength of EL (ElectroLuminescence). The wavelength at which the organic layers constituting the light emitting part emit their own light is called PL (PhotoLuminescence), and the light emitted by this PL (PhotoLuminescence) affected by the cavity peak, which is an optical characteristic, is called EL (ElectroLuminescence). In addition, the cavity peak refers to a point where optical transmittance is maximized. In general, light generated between two mirrors is transmitted to both mirrors (in the present invention, the second electrode is the part where the reflection occurs) It is to find the part where the wavelength of light is maximized through constructive interference by adjusting the thickness and the position of light emission in the light emitting area. In addition, the cavity peak varies depending on the overall thickness of the organic light emitting device, the PL of organic layers, and the thickness of the first electrode.

Therefore, in the present invention, the order of the light emitting layers or the light emitting position of the light emitting layers is set in consideration of the cavity peak and the spectral change rate of the light emitting layers. That is, the order or position of light emission of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer is set in consideration of the cavity peaks and spectral change rates of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer. The results of this experiment will be described with reference to FIGS. 3 to 6 and Table 1. 3 to 6 and Table 1 are measured by configuring a bottom emission type device.

3 is a diagram showing the emission intensity according to a comparative example and a first embodiment of the present invention. 3 can be referred to as an EL spectrum. The emission intensity is a numerical value expressed as a relative value based on the maximum value of the EL spectrum.

In FIGS. 3, 5, and 6, Comparative Examples are composed of two light emitting units including a blue light emitting layer as the first light emitting layer and a yellow-green light emitting layer as the second light emitting layer. In the embodiment, as shown in FIG. 1, the first and second light-emitting layers are composed of blue light-emitting layers, and the third light-emitting layer is three light-emitting parts composed of yellow-green light-emitting layers. The light emitting part may include an electron transport layer (ETL) and a hole transport layer (HTL), and a charge generation layer (CGL) may be included between the two light emitting parts or the three light emitting parts.

In FIG. 3 , solid lines represent examples, and dotted lines represent comparative examples.

As shown in Figure 3, it can be seen that the peak wavelength (λmax) of blue (Blue) appears in the range of 440 nm to 480 nm in the comparative example and the first embodiment of the present invention. It can be seen that the emission intensity of the first embodiment of the present invention further increased at 440 nm to 480 nm, which is the peak wavelength (λmax) of blue, compared to the comparative example.

In Comparative Example, it can be seen that the yellow-green peak wavelength (λmax) appears at 530 nm to 590 nm. It can be seen that in the first embodiment of the present invention, the peak wavelength (λmax) region is moved to the left side compared to the comparative example. That is, it can be seen that the yellow-green peak wavelength (λmax) appears at 540 nm to 575 nm. In addition, it can be seen that the first embodiment of the present invention has a more increased yellow-green emission intensity compared to the comparative example.

This is because in the comparative example, since yellow-green must be emitted at 530 nm to 590 nm, an unnecessary light emitting area is increased, and thus the light emitting intensity is lower than that of the first embodiment. In Comparative Example, since the luminous intensity is lowered, the luminous efficiency of yellow-green is lowered. Therefore, the color viewing angle and color gamut according to the viewing angle caused by the difference in efficiency according to the light emission color are lowered.

In addition, it can be seen that in the first embodiment of the present invention, the yellow-green emission intensity increased compared to the comparative example. This is done by setting the peak wavelength (λmax) of the yellow-green light emitting layer to 540 nm to 575 nm in consideration of the yellow-green cavity peak and the spectral change rate according to the viewing angle, Since the unnecessary light emitting area is reduced, the light emitting intensity is increased. Accordingly, since the green efficiency is increased, the luminous efficiency of the yellow-green light emitting layer is increased. Therefore, the color viewing angle and color gamut according to the viewing angle caused by the difference in efficiency according to the emission color may be improved.

In addition, since the two light emitting layers in the three light emitting units are composed of the blue light emitting layer, the light emitting efficiency of the blue light emitting layer is increased. That is, since the light emitting intensity of the blue light emitting layer is increased compared to the comparative example, the light emitting efficiency of the blue light emitting layer is increased. Accordingly, the color viewing angle (Δu'v') and the color gamut according to the viewing angle caused by the difference in efficiency according to the emission color may be improved.

And, the spectral change rate according to the viewing angle of the light emitting layer will be described with reference to FIG. 4 .

4 is a diagram showing a spectrum change rate according to a viewing angle according to a first embodiment of the present invention.

Figure 4 shows the measurement of the luminous intensity while looking at an angle from 0 ° to 15 °, 30 °, 45 °, and 60 ° as viewed from the front. The emission intensity is a numerical value expressed as a relative value based on the maximum value of the EL spectrum.

When composed of two light-emitting parts having two light-emitting layers of a blue light-emitting layer and a yellow-green light-emitting layer, the blue light-emitting layer and the yellow-green light-emitting layer -Green) The rate of change of the spectrum according to the viewing angle of the light emitting layer is different. The spectrum change rate according to the viewing angle of the blue light emitting layer decreases a lot with the viewing angle, but the spectrum change rate according to the viewing angle of the yellow-green light emitting layer slowly decreases with the viewing angle. Viewing angle characteristics of the yellow-green light emitting layer deteriorate. Therefore, in order to improve the color viewing angle characteristics, the blue spectrum change rate and the yellow-green spectrum change rate must be matched. To this end, since the yellow-green cavity peak is aligned to a position that is displaced from the desired position, the efficiency of red, green, and blue is reduced. do.

In the present invention, two blue light emitting layers emitting the same color within three light emitting units are provided to match the blue and yellow-green spectrum change rates and the blue spectrum change rates. placed adjacent to Since the two blue light emitting layers have two blue spectra, it is more advantageous to adjust the yellow-green spectrum change rate by the two blue spectra. That is, the cavity peak of the yellow-green light emitting layer can be positioned at a desired position by the two blue light emitting layers.

In addition, since the two blue light emitting layers are disposed, the difference between the blue spectrum change rate and the yellow-green spectrum change rate is substantially similar, so that the color viewing angle can be improved. Here, the spectrum change rate may be referred to as a spectrum change rate according to a viewing angle. In addition, the spectral change rate may be referred to as a change rate of light emission intensity according to a viewing angle.

In addition, since the two blue light-emitting layers are disposed adjacent to each other, the difference between the blue light-emitting layer and the yellow-green spectrum change rate is almost similar, so that the cavity peak of the blue light-emitting layer ( cavity peak and the cavity peak of the yellow-green light emitting layer may be located in the light emitting region. Here, the spectrum change rate may be referred to as a spectrum change rate according to a viewing angle. In addition, the spectral change rate may be referred to as a change rate of light emission intensity according to a viewing angle.

As shown in FIG. 4, it can be seen that the spectrum change rate according to the viewing angle of the blue light emitting layer and the yellow-green spectrum change rate according to the viewing angle, that is, the change rate of the light emission intensity according to the viewing angle are almost similar. . Therefore, a small rate of change in spectrum according to a viewing angle means that the rate of change in light emission intensity is small according to a viewing angle. Accordingly, a change in color coordinates according to a viewing angle or a color viewing angle may be reduced. In addition, since the spectral change rate according to the viewing angle is small, viewing angle characteristics may be improved.

In addition, since the difference between the spectrum change rate according to the viewing angle of the blue light emitting layer and the spectrum change rate according to the viewing angle of the yellow-green light emitting layer are almost similar, the cavity peak of the blue light emitting layer and the yellow-green light emitting layer A cavity peak of the yellow-green emission layer may be located in a desired emission region. Here, the spectrum change rate may be referred to as a spectrum change rate according to a viewing angle. In addition, the spectral change rate may be referred to as a change rate of light emission intensity according to a viewing angle.

Therefore, the cavity peak of the yellow-green light emitting layer emitting a different color from the same color and the same color are produced by the blue light emitting layers, which are two light emitting layers emitting the same color. A cavity peak of blue light emitting layers, which are light emitting layers, may be located in a light emitting region of the light emitting layers.

The peak wavelength (λmax) corresponding to the emission region of the two blue light emitting layers (EML) 114 and 124 is 440 nm to 480 nm, and the yellow-green light emitting layer (EML) 134 When the peak wavelength (λmax) corresponding to the light emitting region of 540 nm to 575 nm is configured, the light emitting layer emits light in a desired light emitting region, so unnecessary light emitting regions can be minimized. In addition, by setting the peak wavelength (λmax) of the yellow-green light-emitting layer to 540 nm to 575 nm, the third light-emitting layer (EML) 134 in the peak wavelength (λmax) region is yellow-green. -Green) The unnecessary light-emitting area of the light-emitting layer is reduced. In addition, blue and green colors appearing when the peak wavelength (λmax) of the blue light-emitting layer is biased to the right or when the peak wavelength (λmax) of the yellow-green light-emitting layer is biased to the left. ), it is possible to improve the problem of deterioration of color gamut or color viewing angle.

Accordingly, since the light emitting layers can emit light in a desired light emitting region, light emitting efficiency of the light emitting layers can be improved, and panel efficiency, color reproducibility or color viewing angle can be improved.

As described above, since the light emitting intensities of the blue light emitting layer and the yellow-green light emitting layer increase, the light emitting efficiency of the light emitting layer increases. In addition, the color viewing angle (Δu'v') and the color gamut according to the viewing angle may be improved. This will be described with reference to Table 1 and FIGS. 5 and 6 .

Table 1 below measures efficiency and panel efficiency according to the comparative example and the first embodiment of the present invention.

In Table 1, Comparative Example includes two light emitting units including a blue light emitting layer as the first light emitting layer and a yellow-green light emitting layer as the second light emitting layer. In the embodiment, as shown in FIG. 1, the first and second light-emitting layers are composed of blue light-emitting layers, and the third light-emitting layer is three light-emitting parts composed of yellow-green light-emitting layers. As described above, the light emitting part may include an electron transport layer (ETL) and a hole transport layer (HTL), and a charge generating layer (CGL) may be included between the two light emitting parts or the three light emitting parts.

Looking at the efficiency of red, green, blue and white, the red efficiency was measured as 8.0 cd / A in the comparative example and 7.0 cd / A in the example. . Red efficiencies of Comparative Examples and Examples were measured to be similar.

In addition, the green efficiency was measured to be 29.9cd/A in Comparative Example and 38.7cd/A in Example. As shown in FIG. 2, since the yellow-green light emitting layer is located in the desired peak wavelength (λmax) region, it can be seen that the green efficiency is improved by 29% compared to the comparative example. Since the green efficiency increases, the luminous efficiency of the yellow-green light emitting layer also increases.

Blue efficiency was measured to be 2.2 cd/A in Comparative Example and 3.5 cd/A in Example. It can be seen that by configuring the blue light emitting layer with the first light emitting layer and the second light emitting layer in the embodiment, the blue efficiency is improved by 59% compared to the comparative example. Since the blue efficiency increases, the luminous efficiency of the blue light emitting layer also increases.

White efficiency was measured as 72.9cd/A in Comparative Example and 85.8cd/A in Example. It can be seen that the white efficiency is improved by 18% compared to the comparative example by configuring the blue light emitting layer with the first light emitting layer and the second light emitting layer in the embodiment.

In addition, the panel efficiency was measured as 22.9cd/A in the comparative example and 35.5cd/A in the example, and it can be seen that it increased by 55% compared to the comparative example.

5 is a diagram showing color coordinates according to a comparative example and a first embodiment of the present invention. The color coordinates are measured based on the National Television System Committee (NTSC) standards.

The color coordinates are as follows. Red was measured as (0.665, 0.330) in the comparative example and (0.661, 0.329) in the example. Green was measured as (0.317, 0.635) in Comparative Example and (0.295, 0.649) in Example, and blue was measured as (0.142, 0.046) in Comparative Example and (0.143, 0.043) in Example. It became. White was measured as (0.337, 0.338) in the comparative example and (0.285, 0.300) in the example. From this result, it can be seen that the color gamut was improved from 81.7% to 85.5% compared to the comparative example. And, since green is located in a shorter wavelength region compared to the comparative example, it can be seen that the color gamut is improved by having a larger range of color coordinates compared to the comparative example due to the change in color coordinates of green. .

6 is a graph showing color viewing angles (Δu'v') according to viewing angles. As shown in FIG. 6, it is measured while looking at an angle from 0° to 15°, 30°, 45°, and 60° when viewed from the front. And, in FIG. 6 , the solid line represents an embodiment, and the dotted line represents a comparative example.

At a viewing angle of 60° of light emitted from the organic light emitting device, it can be seen that the color viewing angle (Δu'v') of the comparative example is 0.023, and that of the first embodiment is 0.016. In the embodiment, since the color viewing angle (Δu'v') according to the viewing angle is small, the color change rate felt by the consumer according to the viewing angle can be improved. In addition, since the color viewing angle (Δu'v') of white is reduced, it may be advantageous to realize the same color regardless of viewing angle positions when implemented with an organic light emitting display device.

In the present invention, the order of the light emitting layers or the light emitting position of the light emitting layers is set in consideration of the cavity peak and the spectral change rate of the light emitting layers. That is, the order of the first light emitting layer, the second light emitting layer, and the third light emitting layer is set in consideration of the cavity peaks and spectral change rates of the first light emitting layer, the second light emitting layer, and the third light emitting layer. Accordingly, the two light emitting layers emitting the same color are arranged closer to the first electrode than the second electrode, and the light emitting layer emitting a different color from the same color is arranged closer to the second electrode than the first electrode. In addition, since the blue light emitting layers configure the first light emitting layer (EML) 114 and the second light emitting layer (EML) 124 closer to the first electrode 102 than the second electrode 104, the blue color The luminous intensity of the light emitting layer is increased so that the luminous efficiency of the blue light emitting layer is improved, and the panel efficiency, color reproducibility or color viewing angle may be improved. In addition, since the two blue light-emitting layers are configured closer to the first electrode 102 than the second electrode 104, the two blue light-emitting layers are closer to the second electrode than the first electrode 102 ( 104) (herein referred to as “Comparative Example 1”), red efficiency may be increased. This is explained with reference to Table 2 and FIGS. 7 and 8 .

Comparative Example 1 includes three light emitting units including a yellow-green light emitting layer as the first light emitting layer and a blue light emitting layer as the second light emitting layer and the third light emitting layer. And, in practice, the first light emitting layer and the second light emitting layer are composed of blue (Blue) light emitting layer, and the third light emitting layer is composed of three light emitting parts composed of yellow-green (Yellow-Green) light emitting layer. An electron transport layer (ETL) and a hole transport layer (HTL) may be included in the light emitting part, and a charge generation layer (CGL) may be included between the three light emitting parts.

As shown in Table 2, it can be seen that the red efficiency of Comparative Example 1 is 3.7cd/A, and the red efficiency of Example is 7.0cd/A. Therefore, it can be seen that the red efficiency of Example is improved by about 90% compared to 1 in comparison. And, the green efficiency of Comparative Example 1 is 44.2cd / A, the green efficiency of Example is 44.3cd / A, and it can be seen that the green efficiency is similar to that of Comparative Example 1 and Example. . And, the blue efficiency of Comparative Example 1 is 4.2cd/A, the blue efficiency of Example is 4.5cd/A, and the blue efficiency of Example is 7% higher than that of Comparative Example 1. can In addition, it can be seen that the white efficiency of Comparative Example 1 is 82.7cd / A and the Example is 87.7cd / A, and the White efficiency of Example is improved by about 6% compared to Comparative Example 1.

It can be seen that the panel efficiency of Comparative Example 1 was 16.3 cd / A and Example was 30.8 cd / A, and the panel efficiency of Example was improved by about 89% compared to Comparative Example 1.

Therefore, it can be seen that when the two blue light emitting layers are configured closer to the first electrode than the second electrode, red efficiency, blue efficiency, white efficiency, and panel efficiency increase. can In particular, it can be seen that the red efficiency is greatly increased.

* FIG. 7 is a diagram showing emission intensity according to Comparative Example 1 and the first embodiment of the present invention. 7 can be referred to as an EL spectrum. The emission intensity is a numerical value expressed as a relative value based on the maximum value of the EL spectrum. In FIG. 7 , Comparative Example 1 is indicated by a dotted line, and Examples are indicated by a solid line.

As shown in FIG. 7, it can be seen that in Comparative Example 1 and Example, the peak wavelength (λmax) of blue appears in the range of 440 nm to 480 nm. In Example, it can be seen that the emission intensity further increased at 440 nm to 480 nm, which is the peak wavelength (λmax) of blue, compared to Comparative Example 1.

In Comparative Example 1, it can be seen that the yellow-green peak wavelength (λmax) appears at 530 nm to 590 nm. And, in the embodiment, it can be seen that the yellow-green peak wavelength (λmax) appears at 540 nm to 575 nm. In Example and Comparative Example 1, it can be seen that the yellow-green emission intensity is similar.

And, it can be seen that in Comparative Example 1 and Example, the peak wavelength (λmax) of red appears in the range of 600 nm to 650 nm. In Example, it can be seen that the emission intensity further increased at 600 nm to 650 nm, which is the peak wavelength (λmax) of the red (Blue) light emitting layer, compared to Comparative Example 1.

The color viewing angle Δu'v' according to the viewing angle will be described with reference to FIG. 8 .

8 is a graph showing color viewing angles (Δu'v') according to viewing angles. As shown in FIG. 8, it is measured while looking at an angle from 0° to 15°, 30°, 45°, and 60° when viewed from the front. In FIG. 8 , Comparative Example 1 is indicated by a dotted line and Examples are indicated by a solid line.

It can be seen that the color viewing angle (Δu'v') of Comparative Example 1 was 0.100 and that of Example 0.016 at a viewing angle of 60° of light emitted from the organic light emitting device. In the embodiment, since the color viewing angle (Δu'v') according to the viewing angle is small, the color change rate felt by the consumer according to the viewing angle can be improved. In addition, since the color viewing angle (Δu'v') of white is reduced, it may be advantageous to realize the same color regardless of viewing angle positions when implemented with an organic light emitting display device.

Therefore, when the two blue light emitting layers are configured closer to the first electrode than the second electrode, since the intensity of red light is increased, the color viewing angle and Color gamut can be improved.

However, it is also possible to apply the structure of Comparative Example 1 when designing an organic light emitting device with a structure capable of increasing red efficiency.

Although three light emitting units have been described as an example in the embodiment of the present invention, at least three or more light emitting units may be configured, and at least two of the three or more light emitting units may be configured as light emitting units emitting the same color. By configuring two light emitting units emitting the same color closer to the first electrode than to the second electrode, the light emitting efficiency of the light emitting layer can be improved, and the color viewing angle or color gamut according to panel efficiency and viewing angle can be improved.

9 is a schematic cross-sectional view showing a white organic light emitting device according to a second embodiment of the present invention. Hereinafter, in describing the present embodiment, description of components identical to or corresponding to those of the previous embodiment will be omitted.

The white organic light emitting device 200 shown in FIG. 9 includes first and second electrodes 202 and 204 on a substrate 201 and a first light emitting unit 210 and a second electrode 202 and 204 between the first and second electrodes 202 and 204 . A light emitting unit 220 and a third light emitting unit 230 are provided.

The first electrode 202 is an anode supplying holes and may be formed of gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), or an alloy thereof, , but is not necessarily limited thereto.

The second electrode 204 is a cathode supplying electrons and may be formed of a transparent conductive material such as TCO (Transparent Conductive Oxide) such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IGZO (Indium Gallium Zinc Oxide), or the like. may be, but is not necessarily limited thereto. Alternatively, the second electrode 204 may be formed of metallic materials such as gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), or an alloy thereof, It is not necessarily limited to this. Alternatively, the second electrode 204 may include transparent conductive oxide (TCO), indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), and metallic materials such as gold (Au) and silver (Ag). , aluminum (Al), molybdenum (Mo), may be formed of two layers such as magnesium (Mg), but is not necessarily limited thereto.

The first electrode 202 and the second electrode 204 may be referred to as an anode or a cathode, respectively.

The first electrode 202 may be a reflective electrode, and the second electrode 204 may be a transflective electrode.

The second embodiment of the present invention relates to the position of the first electrode 202 from the second electrode 204, the first light emitting layer of the first light emitting part 210, and the first light emitting layer of the second light emitting part 220. Light emitting efficiency and color viewing angle may be improved by setting light emitting positions of the second light emitting layer and the third light emitting layer of the third light emitting unit 230 .

The position L0 of the first electrode 202 is set to be 500 nm to 600 nm from the second electrode 204 . Alternatively, the position L0 of the first electrode 202 is set to be located within a range of 500 nm to 600 nm from the reflective surface of the second electrode 204 . In addition, the emission peak of the light emitting layer constituting the first light emitting part 210, the second light emitting part 220, and the third light emitting part 230 is located at a specific wavelength, and the light of the specific wavelength By emitting light, the luminous efficiency can be improved. In addition, the first light emitting unit 210, the second light emitting unit 220, and the third light emitting unit 230 have a maximum light emitting range in the light emitting regions of the first light emitting layer, the second light emitting layer, and the third light emitting layer. can have

The third light emitting part 230 includes a third electron transport layer (ETL) 236, a third light emitting layer (EML) 234, and a third hole transport layer (HTL 232) under the second electrode 204. Although not shown in the figure, an electron injection layer (EIL) may be additionally formed on the third electron transport layer (ETL) 136. The electron injection layer (EIL) may include the second electrode ( 204) serves to inject electrons into the third electron transport layer (ETL) 236.

The third electron transport layer (ETL) 236 may be configured by applying two or more layers or two or more materials.

The third hole transport layer (HTL) 232 may be configured by applying two or more layers or two or more materials.

A hole injection layer (HIL) may be further formed under the third hole transport layer (HTL) 232 .

A hole blocking layer (HBL) may be additionally formed on the third light emitting layer (EML) 234 . The third electron transport layer (ETL) 236 and the hole blocking layer (HBL) may be configured as one layer.

An electron blocking layer (EBL) may be further formed under the third light emitting layer (EML) 234 . The third hole transport layer (HTL) 232 and the electron blocking layer (EBL) may be configured as one layer.

The third light emitting layer (EML) 234 is a yellow-green light emitting layer, or a green light emitting layer, or a yellow light emitting layer and a red light emitting layer, or a red light emitting layer and a green ( Green) light emitting layer, or a yellow-green light emitting layer and a red light emitting layer, or a combination thereof. When a red light emitting layer is further formed in the yellow-green light emitting layer, efficiency of the red light emitting layer may be further improved. The red light emitting layer may be formed above or below the yellow-green light emitting layer. And, the yellow light emitting layer and the red light emitting layer, or the red light emitting layer and the green light emitting layer, or the yellow-green light emitting layer and the red light emitting layer are the third light emitting layer ( It is also possible to configure above or below the EML) (234). In addition, the yellow light emitting layer and the red light emitting layer, or the red light emitting layer and the green light emitting layer, or the yellow-green light emitting layer and the red light emitting layer are the third light emitting layer ( EML) above and below the 234 may be configured identically or differently.

In addition, the peak wavelength (λmax) of the yellow light emitting layer may be in the range of 540 nm to 580 nm. The peak wavelength (λmax) of the red light emitting layer may be in the range of 600 nm to 650 nm. Accordingly, peak wavelengths (λmax) of the yellow light emitting layer and the red light emitting layer may be in the range of 540 nm to 650 nm. Here, the peak wavelength may be a light emitting region. When composed of two layers of the yellow light emitting layer and the red light emitting layer, the luminous efficiency of the red light emitting layer can be increased.

And, the peak wavelength (λmax) of the red light emitting layer may be in the range of 600 nm to 650 nm. The peak wavelength (λmax) of the green light emitting layer may be in the range of 510 nm to 560 nm. Accordingly, the peak wavelengths (λmax) of the red light emitting layer and the green light emitting layer may be in the range of 510 nm to 650 nm. Here, the peak wavelength may be a light emitting region. When composed of two layers of the red light emitting layer and the green light emitting layer, the color reproducibility can be improved.

In addition, the peak wavelength (λmax) of the yellow light emitting layer may be in the range of 540 nm to 580 nm. The peak wavelength of the red light emitting layer may be in the range of 600 nm to 650 nm. Accordingly, peak wavelengths (λmax) of the yellow light emitting layer and the red light emitting layer may be in the range of 540 nm to 650 nm. Here, the peak wavelength may be a light emitting region. When composed of two layers of the yellow light emitting layer and the red light emitting layer, the luminous efficiency of the red light emitting layer can be increased.

In addition, according to the characteristics or structure of the device, the third light emitting layer (EML) 234 of the third light emitting part 230 is composed of two layers of a red light emitting layer and a yellow-green light emitting layer. can do. The peak wavelength (λmax) of the red light emitting layer may be in the range of 600 nm to 650 nm. The peak wavelength (λmax) of the yellow-green light emitting layer may be in the range of 510 nm to 580 nm. When composed of two layers of the red light emitting layer and the yellow-green light emitting layer, the luminous efficiency of the red light emitting layer can be increased. In this case, the peak wavelength λmax of the third light emitting layer (EML) 234 may be in the range of 510 nm to 650 nm. Here, the peak wavelength may be a light emitting region.

The third light emitting layer (EML) 234 is a yellow-green light emitting layer, or a yellow light emitting layer and a red light emitting layer, or a red light emitting layer and a green light emitting layer, or a yellow-green light emitting layer. When composed of one of a yellow-green light emitting layer and a red light emitting layer or a combination thereof, the peak wavelength of the third light emitting layer (EML) 234 is in the range of 510 nm to 650 nm. can be done with Here, the peak wavelength may be a light emitting region.

The peak wavelength (λmax) of the yellow-green light emitting layer may be in the range of 540 nm to 575 nm. Here, the peak wavelength may be a light emitting region.

Therefore, the light emitting position L1 of the third light emitting layer (EML) 234 is 20 nm from the second electrode 204 so that the light emitting efficiency, color viewing angle or color gamut of the third light emitting layer (EML) 234 is improved. to 80 nm. Alternatively, the light emitting position L1 of the third light emitting layer (EML) 234 may be set to be positioned within a range of 20 nm to 80 nm from the reflective surface of the second electrode 204 .

The second light emitting part 220 may include a second hole transport layer (HTL) 222 , a second light emitting layer (EML) 224 , and a second electron transport layer (ETL) 226 .

Although not shown in the drawings, the second light emitting part 220 may additionally include an electron injection layer (EIL) on the second electron transport layer (ETL) 226 .

The second electron transport layer (ETL) 226 may be made of the same material as the third electron transport layer (ETL) 236, but is not necessarily limited thereto.

The second electron transport layer (ETL) 226 may be formed by applying two or more layers or two or more materials.

The second hole transport layer (HTL) 222 may be made of the same material as the third hole transport layer (HTL) 232, but is not necessarily limited thereto.

The second hole transport layer (HTL) 222 may be formed by applying two or more layers or two or more materials.

A hole injection layer (HIL) may be further formed under the second hole transport layer (HTL) 222 . The hole injection layer (HIL) serves to inject holes from the first charge generation layer (CGL) 240 into the second hole transport layer (HTL) 222 .

A hole blocking layer (HBL) may be additionally formed on the second light emitting layer (EML) 224 . The second electron transport layer (ETL) 226 and the hole blocking layer (HBL) may be configured as one layer.

An electron blocking layer (EBL) may be additionally formed under the second light emitting layer (EML) 224 . The second hole transport layer (HTL) 222 and the electron blocking layer (EBL) may be configured as one layer.

The second light emitting layer (EML) 224 may include a blue light emitting layer. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer. Since the deep blue light emitting layer is located in a shorter wavelength region than the blue light emitting layer, it may be advantageous to improve color reproducibility and luminance.

The peak wavelength λmax of the second light emitting layer (EML) 224 may be in the range of 440 nm to 480 nm. Here, the peak wavelength may be a light emitting region.

Alternatively, the first light emitting layer (EML) 224 may include a blue light emitting layer and an auxiliary light emitting layer capable of emitting light of a different color. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer. The auxiliary light emitting layer may be composed of one of a yellow-green light emitting layer, a red light emitting layer, and a green light emitting layer, or a combination thereof. The compensator auxiliary light emitting layer may be composed of one of a yellow-green light emitting layer, a red light emitting layer, a green light emitting layer, or a combination thereof. When the auxiliary light emitting layer is further formed, the luminous efficiency of the green light emitting layer or the red light emitting layer may be further improved. When configuring the second light emitting layer (EML) 224 including the auxiliary light emitting layer, the yellow-green light emitting layer, the red light emitting layer, or the green light emitting layer is the second light emitting layer (EML). It is also possible to construct above or below (224).

In addition, as the auxiliary light emitting layer, a yellow-green or red light emitting layer or a green light emitting layer may be configured identically or differently above and below the second light emitting layer (EML) 224 . there is. The location or number of light emitting layers can be selectively arranged according to the configuration and characteristics of the device, but is not necessarily limited thereto.

The peak wavelength λmax of the second light emitting layer (EML) 224 including the yellow-green light emitting layer as the auxiliary light emitting layer may be in the range of 440 nm to 590 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength λmax of the second light emitting layer (EML) 224 including the red light emitting layer, which is the auxiliary light emitting layer, may be in the range of 440 nm to 650 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength λmax of the second light emitting layer (EML) 224 including the green light emitting layer, which is the auxiliary light emitting layer, may be in the range of 440 nm to 570 nm. Here, the peak wavelength may be a light emitting region.

Therefore, the light emitting position L2 of the second light emitting layer (EML) 224 is 150 nm from the second electrode 204 so that the light emitting efficiency, color viewing angle or color gamut of the second light emitting layer (EML) 224 is improved. to 200 nm. Alternatively, the light emitting position L2 of the second light emitting layer (EML) 224 may be set to be positioned within a range of 150 nm to 200 nm from the reflective surface of the second electrode 204 .

A second charge generating layer (CGL) 250 may be further formed between the second light emitting part 220 and the third light emitting part 230 . The second charge generating layer (CGL) 250 adjusts the charge balance between the second and third light emitting parts 220 and 230 . The second charge generation layer (CGL) 250 may include an N-type charge generation layer (N-CGL) and a P-type charge generation layer (P-CGL). Also, the second charge generating layer (CGL) 150 may be formed of a single layer.

The first light emitting part 210 includes a first hole transport layer (HTL) 212, a first light emitting layer (EML) 214, and a first electron transport layer (ETL 216) on the first electrode 202. It can be done.

Although not shown in the drawing, a hole injection layer (HIL) may be additionally formed on the first electrode 202 .

In the first light emitting layer (EML) 214, holes supplied through the first hole transport layer (HTL) 212 and electrons supplied through the first electron transport layer (ETL) 216 recombine. so light is generated.

The first hole transport layer (HTL) 212 may be formed by applying two or more layers or two or more materials.

The first electron transport layer (ETL) 216 may be formed by applying two or more layers or two or more materials.

A hole blocking layer (HBL) may be additionally formed on the first light emitting layer (EML) 214 . The first electron transport layer (ETL) 216 and the hole blocking layer (HBL) may be configured as one layer.

An electron blocking layer (EBL) may be further formed under the first light emitting layer (EML) 214 . The first hole transport layer (HTL) 212 and the electron blocking layer (EBL) may be configured as one layer.

A first charge generating layer (CGL) 240 may be further formed between the first light emitting part 210 and the second light emitting part 220 . The first charge generating layer (CGL) 240 controls the charge balance between the first light emitting part 210 and the second light emitting part 220 . The first charge generating layer 240 may include an N-type charge generating layer (N-CGL) and a P-type charge generating layer (P-CGL). Also, the first charge generating layer (CGL) 240 may be formed of a single layer.

The first light emitting layer (EML) 214 may include a blue light emitting layer. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer. Since the deep blue light emitting layer is located in a shorter wavelength region than the blue light emitting layer, it may be advantageous to improve color reproducibility and luminance.

The peak wavelength λmax of the first light emitting layer (EML) 214 may be in the range of 440 nm to 480 nm. Here, the peak wavelength may be a light emitting region.

Alternatively, the first light emitting layer (EML) 214 may include a blue light emitting layer and an auxiliary light emitting layer capable of emitting light of a different color. The auxiliary light emitting layer may be composed of one of a yellow-green light emitting layer, a red light emitting layer, and a green light emitting layer, or a combination thereof. When the auxiliary light emitting layer is further formed, the luminous efficiency of the green light emitting layer or the red light emitting layer may be further improved. When configuring the first light emitting layer (EML) 214 including the auxiliary light emitting layer, the yellow-green light emitting layer, the red light emitting layer, or the green light emitting layer is the first light emitting layer (EML). It is also possible to construct above or below (214).

In addition, as the auxiliary light emitting layer, a yellow-green or red light emitting layer or a green light emitting layer may be identically or differently configured above and below the first light emitting layer (EML) 214 . there is. The location or number of light emitting layers can be selectively arranged according to the configuration and characteristics of the device, but is not necessarily limited thereto.

The peak wavelength λmax of the first light emitting layer (EML) 214 including the yellow-green light emitting layer as the auxiliary light emitting layer may be in the range of 440 nm to 590 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength λmax of the first light emitting layer (EML) 214 including the red light emitting layer as the auxiliary light emitting layer may be in the range of 440 nm to 650 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength (λmax) of the first light emitting layer (EML) 114 including the green light emitting layer, which is the auxiliary light emitting layer, may be in the range of 440 nm to 570 nm. Here, the peak wavelength may be a light emitting region.

Therefore, the light emitting position L3 of the first light emitting layer (EML) 214 is 270 nm from the second electrode 204 so that the light emitting efficiency, color viewing angle or color gamut of the first light emitting layer (EML) 214 is improved. to 330 nm. Alternatively, the light emitting position L3 of the first light emitting layer (EML) 214 may be set to be positioned within a range of 270 nm to 330 nm from the reflective surface of the second electrode 204 .

The structure shown in FIG. 9 represents an example of the present invention, and can be selectively configured according to the structure or characteristics of the organic light emitting device, but is not limited thereto.

The light emitting positions of the light emitting layers of the organic light emitting device to which the structure shown in FIG. 9 is applied will be described with reference to FIG. 10 .

10 is a view showing a light emitting position of an organic light emitting device according to a second embodiment of the present invention.

That is, in FIG. 10, the horizontal axis represents the wavelength region of light, and the vertical axis represents the light emitting positions of the light emitting layers constituting the light emitting part from the second electrode 204, which can be referred to as a contour map. Here, except for the first electrode 202 and the second electrode 204, the emission positions of the light emitting layers of the present invention are shown.

Since the third light emitting layer (EML) 234 constituting the third light emitting part 230 is a yellow-green light emitting layer, the peak wavelength (λmax) range of the third light emitting layer (EML) 234 may range from 540 nm to 575 nm.

Therefore, by setting the light emitting position of the third light emitting layer (EML) 234 in the range of 20 nm to 80 nm, the emission peak 234E corresponding to the light emitting region of the third light emitting layer (EML) 234 is The peak wavelength (λmax) of the third light emitting layer (EML) 234 is located between 540 nm and 575 nm. Accordingly, by allowing the yellow-green light emitting layer to emit light at 540 nm to 575 nm, maximum efficiency can be obtained in a white region of a contour map.

Also, depending on the characteristics or structure of the device, the third light emitting layer (EML) 234 of the third light emitting part 230 may be composed of two layers, a yellow light emitting layer and a red light emitting layer. The peak wavelength (λmax) of the light emitting region of the yellow light emitting layer may be in the range of 540 nm to 580 nm. The peak wavelength (λmax) of the light emitting region of the red light emitting layer may be in the range of 600 nm to 650 nm. Therefore, in this case, it is necessary to emit light at 540 nm to 650 nm, which is the light emitting region of the third light emitting layer (EML) 234, to achieve maximum efficiency in the white region of the contour map.

In addition, depending on the characteristics or structure of the device, the third light emitting layer (EML) 234 of the third light emitting part 230 may be composed of two layers of a red light emitting layer and a green light emitting layer. The peak wavelength (λmax) of the light emitting region of the red light emitting layer may be in the range of 600 nm to 650 nm. The peak wavelength (λmax) of the light emitting region of the green light emitting layer may be in the range of 510 nm to 560 nm. Therefore, in this case, the light emitting region of the third light emitting layer (EML) 234 should emit light between 510 nm and 650 nm to achieve maximum efficiency in the white region of the contour map.

In addition, according to the characteristics or structure of the device, the third light emitting layer (EML) 234 of the third light emitting part 230 is composed of two layers of a red light emitting layer and a yellow-green light emitting layer. can do. The peak wavelength (λmax) of the light emitting region of the red light emitting layer may be in the range of 600 nm to 650 nm. The peak wavelength (λmax) of the light emitting region of the yellow-green light emitting layer may be in the range of 510 nm to 580 nm. Therefore, in this case, the light emitting region of the third light emitting layer (EML) 234 should emit light between 510 nm and 650 nm to achieve maximum efficiency in the white region of the contour map.

Therefore, as the third light emitting layer (EML) 234, a yellow-green light emitting layer, a yellow light emitting layer and a red light emitting layer, or a red light emitting layer and a green light emitting layer, or A peak wavelength (λmax) range of the light emitting region of the third light emitting layer (EML) 234 when it is composed of one or a combination of a yellow-green light emitting layer and a red light emitting layer. may be in the range of 510 nm to 650 nm. In this case, the maximum efficiency can be achieved in the white region of the contour map only when the light emitting region of the third light emitting layer (EML) 234 is 510 nm to 650 nm.

Since the second light emitting layer (EML) 224 constituting the second light emitting part 220 is a blue light emitting layer, the peak wavelength λmax range of the light emitting region of the second light emitting layer (EML) 224 is It may range from 440 nm to 480 nm. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer.

Therefore, by setting the light emitting position of the second light emitting layer (EML) 224 in the range of 150 nm to 200 nm, the emission peak 224E corresponding to the light emitting region of the second light emitting layer (EML) 224 is The peak wavelength (λmax) of the second light emitting layer (EML) 224 is located between 440 nm and 480 nm. Therefore, the maximum efficiency can be obtained in the white region of the contour map by emitting light at 440 nm to 480 nm from the blue light emitting layer.

And, as the second light emitting layer (EML) 224, a blue light emitting layer and a yellow-green light emitting layer, or a blue light emitting layer and a red light emitting layer, or a blue light emitting layer and a green light emitting layer (Green) If it is one of the light emitting layers or a combination thereof, the peak wavelength λmax of the light emitting region of the second light emitting layer (EML) 224 may be in the range of 440 nm to 650 nm. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer.

Since the first light emitting layer (EML) 214 constituting the first light emitting part 210 is a blue light emitting layer, the peak wavelength λmax range of the light emitting region of the first light emitting layer (EML) 214 is It may range from 440 nm to 480 nm. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer.

Therefore, by setting the light emitting position of the first light emitting layer (EML) 214 in the range of 270 nm to 330 nm, the emission peak 214E corresponding to the light emitting region of the first light emitting layer (EML) 214 is The peak wavelength (λmax) of the first light emitting layer (EML) 214 is positioned between 440 nm and 480 nm. Therefore, the maximum efficiency can be obtained in the white region of the contour map by emitting light at 440 nm to 480 nm from the blue light emitting layer.

And, as the first light emitting layer (EML) 214, a blue light emitting layer and a yellow-green light emitting layer, or a blue light emitting layer and a red light emitting layer, or a blue light emitting layer and a green light emitting layer (Green) When composed of one of the light emitting layers or a combination thereof, the peak wavelength (λmax) range of the light emitting region of the first light emitting layer (EML) 214 may be in the range of 440 nm to 650 nm. . The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer.

As described above, light is emitted at 440 nm to 480 nm, which is the peak wavelength (λmax) of the blue light emitting layer, and 540 nm to 575 nm, which is the peak wavelength (λmax) of the yellow-green light emitting layer. Therefore, the maximum efficiency can be obtained in the white area of the contour map. Therefore, it can be seen that the light emitting layer can achieve maximum efficiency by setting the emission position of the light emitting layers of the present invention to correspond to the peak wavelength of the light emitting layers. In addition, since the luminous efficiency of the light emitting layer is increased, panel efficiency, color reproducibility, and color viewing angle can be improved.

11 is a diagram showing light emission intensity according to a second embodiment of the present invention. 11 can be referred to as an EL spectrum.

In FIG. 11, the horizontal axis represents the wavelength region of light, and the vertical axis represents the emission intensity. The emission intensity is a numerical value expressed as a relative value based on the maximum value of the EL spectrum.

In FIG. 11, the embodiment (minimum position) is a part set to the minimum position when the emission positions of the light emitting layers are set. For example, when the light emitting position L1 of the third light emitting layer (EML) 234 is in the range of 20 nm to 80 nm from the second electrode 204, the minimum position is set to 20 nm.

The embodiment (maximum position) is a part set to the maximum position when the emission positions of the light emitting layers are set. For example, when the light emitting position L1 of the third light emitting layer (EML) 234 is in the range of 20 nm to 80 nm from the second electrode 204, the maximum position is set to 80 nm.

The embodiment (optimum position) is a part set as the light emitting position of the embodiment of the present invention. For example, when the light emitting position L1 of the third light emitting layer (EML) 234 is in the range of 20 nm to 80 nm from the second electrode 204, the light emitting position in the embodiment is set in the range of 20 nm to 80 nm. will be.

As shown in FIG. 11, when the light emitting position of the present invention is out of the minimum position, a comparison with the optimal position is as follows. It can be seen that the emission intensity decreases in the range of 440 nm to 480 nm, which is the peak wavelength (λmax) range of blue light. In addition, it can be seen that the emission intensity decreases in the range of 540 nm to 575 nm, which is the peak wavelength (λmax) range of yellow-green light. In addition, it can be seen that the emission intensity significantly decreases in the range of the peak wavelength (λmax) of red light from 600 nm to 650 nm.

In addition, when the light emitting position of the present invention is out of the maximum position, a comparison with the optimal position is as follows. It can be seen that the emission intensity decreases in the peak wavelength range of 440 nm to 480 nm of blue light. In addition, it can be seen that the emission intensity decreases in the range of 540 nm to 575 nm, which is the peak wavelength (λmax) range of yellow-green light.

Therefore, it can be seen that the luminous intensity increases in the peak wavelength range of blue light when set to the optimal position of the present invention than when set to the minimum position or maximum position of the embodiment. In addition, it can be seen that the emission intensity increases in the peak wavelength range of yellow-green light when set to the optimal position of the present invention, compared to the case of setting to the minimum position or maximum position of the embodiment. In addition, it can be seen that the emission intensity increases in the peak wavelength range of red light when set to the optimum position of the present invention, compared to the case of setting to the minimum position or maximum position of the embodiment.

12 is a graph showing color viewing angles (Δu'v') according to viewing angles. As shown in FIG. 12, it is measured while looking at an angle from 0° to 15°, 30°, 45°, and 60° when viewed from the front.

In FIG. 12, the embodiment (minimum position) is a part set to the minimum position when the emission positions of the light emitting layers are set. For example, when the light emitting position L1 of the third light emitting layer (EML) 234 is in the range of 20 nm to 80 nm from the second electrode 204, the minimum position is set to 20 nm.

The embodiment (maximum position) is a part set to the maximum position when the emission positions of the light emitting layers are set. For example, when the light emitting position L1 of the third light emitting layer (EML) 234 is in the range of 20 nm to 80 nm from the second electrode 204, the maximum position is set to 80 nm.

The embodiment (optimum position) is a part set as the light emitting position of the embodiment of the present invention. For example, when the light emitting position L1 of the third light emitting layer (EML) 234 is in the range of 20 nm to 80 nm from the second electrode 204, the light emitting position in the embodiment is set in the range of 20 nm to 80 nm. will be.

As shown in FIG. 12, when the light emitting position of the present invention is out of the minimum position, a comparison with the optimal position is as follows. In the case of the optimal position of the present invention, it can be seen that the color viewing angle (Δu'v') at a viewing angle of 60° of light emitted from the organic light emitting device is 0.016. Further, it can be seen that, when the light is out of the minimum position, the color viewing angle (Δu'v') is 0.050 at a viewing angle of 60° of the light emitted from the organic light emitting device. Therefore, when the color viewing angle Δu'v' is out of the minimum position, the color viewing angle (Δu'v') becomes 0.050 or more, and thus, a color change rate according to an angle or a color viewing angle defect occurs on the screen of the organic light emitting display device. Accordingly, the consumer can detect the color change according to the viewing angle.

In addition, when the light emitting position of the present invention is out of the maximum position, a comparison with the optimal position is as follows. In the case of the optimal position of the present invention, it can be seen that the color viewing angle (Δu'v') at a viewing angle of 60° of light emitted from the organic light emitting device is 0.016. Further, it can be seen that when the light is out of the maximum position, the color viewing angle (Δu'v') is 0.070 at a viewing angle of 60° of the light emitted from the organic light emitting device. Therefore, when the color viewing angle Δu'v' is out of the minimum position, the color viewing angle (Δu'v') becomes 0.070 or more, and thus, a color change rate according to an angle or a color viewing angle defect occurs on the screen of the organic light emitting display device. Accordingly, the consumer can detect the color change according to the viewing angle.

Therefore, when set to the optimal position of the present invention rather than to the minimum position or maximum position of the embodiment, it can be seen that the color viewing angle (Δu'v') at a viewing angle of 60° of light emitted from the organic light emitting device of the present invention is 0.016. there is. In the embodiment, since the color viewing angle (Δu'v') according to the viewing angle is small, the color change rate felt by the consumer according to the viewing angle can be improved. In addition, since the color viewing angle (Δu'v') of white is reduced, it may be advantageous to realize the same color regardless of viewing angle positions when implemented with an organic light emitting display device. In addition, it is possible to improve a color change rate according to an angle or a color viewing angle defect on a screen of an organic light emitting display device.

In addition, light emitting positions of the first light emitting layer, the second light emitting layer, and the third light emitting layer may be set to improve light emitting efficiency and a color viewing angle in consideration of a spectral change rate and a cavity peak of the light emitting layers.

A location of the first electrode may be in a range of 500 nm to 600 nm from the second electrode.

A light emitting position of the third light emitting layer may be in a range of 20 nm to 80 nm from the second electrode.

A light emitting position of the second light emitting layer may be in a range of 150 nm to 200 nm from the second electrode.

A light emitting position of the first light emitting layer may be in a range of 270 nm to 330 nm from the second electrode.

A color viewing angle (Δu'v') of light emitted from the organic light emitting device may be 0.016 or less at a 60° viewing angle.

13 is a view showing a white organic light emitting diode according to a third embodiment of the present invention. In describing the present embodiment, descriptions of elements identical to or corresponding to those of the previous embodiment will be omitted.

In this embodiment, the light emitting position of the light emitting layers is set from the first electrode, and the light emitting position can be set from the first electrode according to device design.

The first electrode 302 and the second electrode 304 may be referred to as an anode or a cathode, respectively.

The first electrode 302 may be a reflective electrode, and the second electrode 304 may be a transflective electrode.

The first light-emitting part 310 includes a first hole transport layer (HTL) 312, a first light-emitting layer (EML) 314, and a first electron transport layer (ETL) 316 on the first electrode 302. can be done by

The third embodiment of the present invention relates to the location of the second electrode 304 from the first electrode 302, the first light emitting layer of the first light emitting part 310, and the first light emitting layer of the second light emitting part 320. Light emission efficiency, color viewing angle, or color reproducibility may be improved by setting light emitting positions of the second light emitting layer and the third light emitting layer of the third light emitting unit 330 .

The position L0 of the second electrode 304 is set to be 500 nm to 600 nm from the first electrode 302 . Alternatively, the position L0 of the second electrode 304 is set to be positioned within a range of 500 nm to 600 nm from the interface between the substrate 301 and the first electrode 302 . In addition, the emission peak of the light emitting layer constituting the first light emitting part 310, the second light emitting part 320, and the third light emitting part 330 is located at a specific wavelength, and the light of the specific wavelength By emitting light, the luminous efficiency can be improved. In addition, the first light emitting part 310, the second light emitting part 320, and the third light emitting part 330 have a maximum light emitting range in light emitting regions of the first light emitting layer, the second light emitting layer, and the third light emitting layer. can have

The first light emitting part 310 includes a first hole transport layer (HTL) 312, a first light emitting layer (EML) 314, and a first electron transport layer (ETL 316) on the first electrode 302. It can be done.

Although not shown in the drawings, a hole injection layer (HIL) may be additionally formed on the first electrode 302 .

The first hole transport layer (HTL) 312 may be formed by applying two or more layers or two or more materials.

The first electron transport layer (ETL) 316 may be formed by applying two or more layers or two or more materials.

A hole blocking layer (HBL) may be additionally formed on the first light emitting layer (EML) 214 . The first electron transport layer (ETL) 316 and the hole blocking layer (HBL) may be configured as one layer.

An electron blocking layer (EBL) may be additionally formed under the first light emitting layer (EML) 314 . The first hole transport layer (HTL) 312 and the electron blocking layer (EBL) may be configured as one layer.

The first light emitting layer (EML) 314 may include a blue light emitting layer. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer. Since the deep blue light emitting layer is located in a shorter wavelength region than the blue light emitting layer, it may be advantageous to improve color reproducibility and luminance.

The peak wavelength λmax of the first light emitting layer (EML) 314 may be in the range of 440 nm to 480 nm. Here, the peak wavelength may be a light emitting region.

Alternatively, the first light emitting layer (EML) 314 may include a blue light emitting layer and an auxiliary light emitting layer capable of emitting light of a different color. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer. The auxiliary light emitting layer may be composed of one of a yellow-green light emitting layer, a red light emitting layer, and a green light emitting layer, or a combination thereof. When the auxiliary light emitting layer is further formed, the luminous efficiency of the green light emitting layer or the red light emitting layer may be further improved. When configuring the first light emitting layer (EML) 314 including the auxiliary light emitting layer, the yellow-green light emitting layer, the red light emitting layer, or the green light emitting layer is the first light emitting layer (EML). It is also possible to construct above or below 314.

In addition, as the auxiliary light emitting layer, a yellow-green or red light emitting layer or a green light emitting layer may be configured identically or differently above and below the first light emitting layer (EML) 314 . there is. The location or number of light emitting layers can be selectively arranged according to the configuration and characteristics of the device, but is not necessarily limited thereto.

The peak wavelength λmax of the first light emitting layer (EML) 314 including the yellow-green light emitting layer as the auxiliary light emitting layer may be in the range of 440 nm to 590 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength λmax of the first light emitting layer (EML) 314 including the red light emitting layer as the auxiliary light emitting layer may be in the range of 440 nm to 650 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength λmax of the first light emitting layer (EML) 314 including the green light emitting layer, which is the auxiliary light emitting layer, may be in the range of 440 nm to 570 nm. Here, the peak wavelength may be a light emitting region.

Therefore, the light emitting position L1 of the first light emitting layer (EML) 314 is 100 nm from the first electrode 302 so that the light emitting efficiency, color viewing angle or color gamut of the first light emitting layer (EML) 314 is improved. to 150 nm. Alternatively, the light emitting position L1 of the first light emitting layer (EML) 314 may be set to be located within a range of 100 nm to 150 nm from the interface between the substrate 301 and the first electrode 302 .

The second light emitting part 320 may include a second hole transport layer (HTL) 322 , a second light emitting layer (EML) 324 , and a second electron transport layer (ETL) 326 .

Although not shown in the figure, the second light emitting part 320 may additionally include an electron injection layer (EIL) on the second electron transport layer (ETL) 326 .

The second electron transport layer (ETL) 326 may be formed by applying two or more layers or two or more materials.

The second hole transport layer (HTL) 322 may be configured by applying two or more layers or two or more materials.

A hole injection layer (HIL) may be further formed under the second hole transport layer (HTL) 322 .

A hole blocking layer (HBL) may be additionally formed on the second light emitting layer (EML) 324 . The second electron transport layer (ETL) 326 and the hole blocking layer (HBL) may be configured as one layer.

An electron blocking layer (EBL) may be additionally formed under the second light emitting layer (EML) 324 . The second hole transport layer (HTL) 322 and the electron blocking layer (EBL) may be configured as one layer.

The second light emitting layer (EML) 324 is composed of a blue light emitting layer. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer. Since the deep blue light emitting layer is located in a shorter wavelength region than the blue light emitting layer, it may be advantageous to improve color reproducibility and luminance.

The peak wavelength λmax of the second light emitting layer (EML) 324 may be in the range of 440 nm to 480 nm. Here, the peak wavelength may be a light emitting region.

Alternatively, the second light emitting layer (EML) 324 may include a blue light emitting layer and an auxiliary light emitting layer capable of emitting light of a different color. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer. The auxiliary light emitting layer may be composed of one of a yellow-green light emitting layer, a red light emitting layer, and a green light emitting layer, or a combination thereof. When the auxiliary light emitting layer is further formed, the luminous efficiency of the green light emitting layer or the red light emitting layer may be further improved. When configuring the second light emitting layer (EML) 324 including the auxiliary light emitting layer, the yellow-green light emitting layer, the red light emitting layer, or the green light emitting layer is the second light emitting layer (EML). It is also possible to construct above or below 324.

In addition, as the auxiliary light emitting layer, a yellow-green or red light emitting layer or a green light emitting layer may be configured identically or differently above and below the second light emitting layer (EML) 324 . there is. The location or number of light emitting layers can be selectively arranged according to the configuration and characteristics of the device, but is not necessarily limited thereto.

The peak wavelength λmax of the second light emitting layer (EML) 324 including the yellow-green light emitting layer as the auxiliary light emitting layer may be in the range of 440 nm to 590 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength λmax of the second light emitting layer (EML) 324 including the red light emitting layer, which is the auxiliary light emitting layer, may be in the range of 440 nm to 650 nm. Here, the peak wavelength may be a light emitting region. In addition, the peak wavelength λmax of the second light emitting layer (EML) 324 including the green light emitting layer, which is the auxiliary light emitting layer, may be in the range of 440 nm to 570 nm. Here, the peak wavelength may be a light emitting region.

Therefore, the light emitting position L2 of the second light emitting layer (EML) 324 is 240 nm from the first electrode 302 so that the light emitting efficiency, color viewing angle or color gamut of the second light emitting layer (EML) 324 is improved. to 280 nm. Alternatively, the light emitting position L2 of the second light emitting layer (EML) 324 may be set to be positioned within a range of 240 nm to 280 nm from the interface between the substrate 301 and the second electrode 302 .

A first charge generating layer (CGL) 340 may be further formed between the first light emitting part 310 and the second light emitting part 320 . The first charge generating layer (CGL) 340 adjusts the charge balance between the first light emitting part 310 and the second light emitting part 320 . The first charge generating layer 340 may include an N-type charge generating layer (N-CGL) and a P-type charge generating layer (P-CGL). Also, the first charge generating layer (CGL) 340 may be formed of a single layer.

The third light emitting part 330 includes a third electron transport layer (ETL) 336, a third light emitting layer (EML) 334, and a third hole transport layer (HTL 332) under the second electrode 304. Although not shown in the figure, an electron injection layer (EIL) may be additionally formed on the third electron transport layer (ETL) 336 .

The third electron transport layer (ETL) 336 may be configured by applying two or more layers or two or more materials.

The third hole transport layer (HTL) 332 may be formed by applying two or more layers or two or more materials.

A hole injection layer (HIL) may be further formed under the third hole transport layer (HTL) 332 .

A hole blocking layer (HBL) may be additionally formed on the third light emitting layer (EML) 334 . The third electron transport layer (ETL) 336 and the hole blocking layer (HBL) may be configured as one layer.

An electron blocking layer (EBL) may be further formed under the third light emitting layer (EML) 334 . The third hole transport layer (HTL) 332 and the electron blocking layer (EBL) may be configured as one layer.

A second charge generation layer (CGL) 350 may be further formed between the second light emitting part 320 and the third light emitting part 330 . The second charge generating layer (CGL) 350 adjusts the charge balance between the second and third light emitting parts 320 and 330 . The second charge generation layer (CGL) 350 may include an N-type charge generation layer (N-CGL) and a P-type charge generation layer (P-CGL). Also, the second charge generating layer (CGL) 350 may be formed of a single layer.

The third light emitting layer (EML) 334 is a yellow-green light emitting layer, or a yellow light emitting layer and a red light emitting layer, or a red light emitting layer and a green light emitting layer, or a yellow-green light emitting layer. It may be composed of one of a yellow-green light emitting layer and a red light emitting layer, or a combination thereof. When a red light emitting layer is further formed in the yellow-green light emitting layer, efficiency of the red light emitting layer may be further improved. The red light emitting layer may be formed above or below the yellow-green light emitting layer. And, the yellow light emitting layer and the red light emitting layer, or the red light emitting layer and the green light emitting layer, or the yellow-green light emitting layer and the red light emitting layer are the third light emitting layer ( It is also possible to configure above or below the EML) (334). In addition, the yellow light emitting layer and the red light emitting layer, or the red light emitting layer and the green light emitting layer, or the yellow-green light emitting layer and the red light emitting layer are the third light emitting layer ( EML) above and below the 334 may be configured identically or differently.

In addition, the peak wavelength (λmax) of the yellow light emitting layer may be in the range of 540 nm to 580 nm. The peak wavelength of the red light emitting layer may be in the range of 600 nm to 650 nm. Accordingly, peak wavelengths (λmax) of the yellow light emitting layer and the red light emitting layer may be in the range of 540 nm to 650 nm. Here, the peak wavelength may be a light emitting region. When composed of two layers of the yellow light emitting layer and the red light emitting layer, the luminous efficiency of the red light emitting layer can be increased.

And, the peak wavelength (λmax) of the red light emitting layer may be in the range of 600 nm to 650 nm. A peak wavelength of the green light emitting layer may be in the range of 510 nm to 560 nm. Accordingly, the peak wavelengths (λmax) of the red light emitting layer and the green light emitting layer may be in the range of 510 nm to 650 nm. Here, the peak wavelength may be a light emitting region. When composed of two layers of the red light emitting layer and the green light emitting layer, the color reproducibility can be improved.

In addition, the peak wavelength (λmax) of the yellow light emitting layer may be in the range of 540 nm to 580 nm. The peak wavelength of the red light emitting layer may be in the range of 600 nm to 650 nm. Accordingly, peak wavelengths (λmax) of the yellow light emitting layer and the red light emitting layer may be in the range of 540 nm to 650 nm. Here, the peak wavelength may be a light emitting region. When composed of two layers of the yellow light emitting layer and the red light emitting layer, the luminous efficiency of the red light emitting layer can be increased.

In addition, according to the characteristics or structure of the device, the third light emitting layer (EML) 334 of the third light emitting part 330 is composed of two layers of a red light emitting layer and a yellow-green light emitting layer. can do. The peak wavelength (λmax) of the red light emitting layer may be in the range of 600 nm to 650 nm. The peak wavelength (λmax) of the yellow-green light emitting layer may be in the range of 510 nm to 580 nm. When composed of two layers of the red light emitting layer and the yellow-green light emitting layer, the luminous efficiency of the red light emitting layer can be increased. In this case, the peak wavelength λmax of the third light emitting layer (EML) 334 may be in the range of 510 nm to 650 nm. Here, the peak wavelength may be a light emitting region.

The third light emitting layer (EML) 334 is a yellow-green light emitting layer, or a yellow light emitting layer and a red light emitting layer, or a red light emitting layer and a green light emitting layer, or a yellow-green light emitting layer. When composed of one of a green light emitting layer and a red light emitting layer or a combination thereof, the peak wavelength λmax of the third light emitting layer (EML) 334 is in the range of 510 nm to 650 nm. can do. Here, the peak wavelength may be a light emitting region.

The peak wavelength (λmax) of the yellow-green light emitting layer may be in the range of 540 nm to 575 nm. Here, the peak wavelength may be a light emitting region.

Therefore, the light emitting position L3 of the third light emitting layer (EML) 334 is 370 nm from the first electrode 302 so that the light emitting efficiency, color viewing angle, or color gamut of the third light emitting layer (EML) 334 is improved. to 410 nm. Alternatively, the light emitting position L3 of the third light emitting layer (EML) 334 may be set to be positioned within a range of 370 nm to 410 nm from the interface between the substrate 301 and the first electrode 302 .

The structure shown in FIG. 13 represents an example of the present invention, and can be selectively configured according to the structure or characteristics of the organic light emitting device, but is not limited thereto.

The light emitting positions of the light emitting layers of the organic light emitting device to which the structure shown in FIG. 13 is applied will be described with reference to FIG. 14 .

14 is a diagram showing a light emitting position of an organic light emitting device according to a third embodiment of the present invention.

That is, in FIG. 14, the horizontal axis represents the wavelength region of light, and the vertical axis represents the light emitting positions of the light emitting layers constituting the light emitting part from the second electrode 204, which can be referred to as a contour map. Here, except for the first electrode 302 and the second electrode 304, the emission positions of the light emitting layers of the present invention are shown.

Since the first light emitting layer (EML) 314 constituting the first light emitting part 310 is a blue light emitting layer, the peak wavelength λmax range of the light emitting region of the first light emitting layer (EML) 314 is It may range from 440 nm to 480 nm. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer.

And, as the first light emitting layer (EML) 314, a blue light emitting layer and a yellow-green light emitting layer, or a blue light emitting layer and a red light emitting layer, or a blue light emitting layer and a green light emitting layer In the case of being one of the (Green) light emitting layers or a combination thereof, the peak wavelength (λmax) of the light emitting region of the first light emitting layer (EML) 314 may be in the range of 440 nm to 650 nm. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer.

Therefore, by setting the light emitting position of the first light emitting layer (EML) 314 in the range of 100 nm to 150 nm, the emission peak 314E corresponding to the light emitting region of the first light emitting layer (EML) 314 is The peak wavelength (λmax) of the first light emitting layer (EML) 314 is positioned between 440 nm and 480 nm. Therefore, the maximum efficiency can be obtained in the white region of the contour map by emitting light at 440 nm to 480 nm from the blue light emitting layer.

The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer.

Since the second light emitting layer (EML) 324 constituting the second light emitting part 320 is a blue light emitting layer, the peak wavelength λmax range of the light emitting region of the second light emitting layer (EML) 324 is It may range from 440 nm to 480 nm.

Therefore, by setting the light emitting position of the second light emitting layer (EML) 324 in the range of 240 nm to 280 nm, the emission peak 324E corresponding to the light emitting region of the second light emitting layer (EML) 324 is The peak wavelength (λmax) of the second light emitting layer (EML) 324 is positioned between 440 nm and 480 nm. Therefore, the maximum efficiency can be obtained in the white region of the contour map by emitting light at 440 nm to 480 nm from the blue light emitting layer. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer.

And, as the second light emitting layer (EML) 324, a blue light emitting layer and a yellow-green light emitting layer, or a blue light emitting layer and a red light emitting layer, or a blue light emitting layer and a green light emitting layer In the case of being one of the (Green) light emitting layers or a combination thereof, the peak wavelength λmax of the light emitting region of the second light emitting layer (EML) 324 may be in the range of 440 nm to 650 nm. The blue light emitting layer may include one of a blue light emitting layer, a deep blue light emitting layer, and a sky blue light emitting layer.

Since the third light emitting layer (EML) 334 constituting the third light emitting part 330 is a yellow-green light emitting layer, the peak wavelength (λmax) range of the third light emitting layer (EML) 234 may range from 540 nm to 575 nm.

Therefore, by setting the light emitting position of the third light emitting layer (EML) 334 in the range of 370 nm to 410 nm, the emission peak 334E corresponding to the light emitting region of the third light emitting layer (EML) 334 is The peak wavelength (λmax) of the third light emitting layer (EML) 334 is located between 540 nm and 575 nm. Accordingly, by allowing the yellow-green light emitting layer to emit light at 540 nm to 575 nm, maximum efficiency can be obtained in a white region of a contour map.

Also, depending on the characteristics or structure of the device, the third light emitting layer (EML) 334 of the third light emitting part 330 may be composed of two layers, a yellow light emitting layer and a red light emitting layer. The peak wavelength (λmax) of the light emitting region of the yellow light emitting layer may be in the range of 540 nm to 580 nm. The peak wavelength (max) of the light emitting region of the red light emitting layer may be in the range of 600 nm to 650 nm. Accordingly, in this case, the light emitting region of the third light emitting layer (EML) 334 must emit light between 540 nm and 650 nm to achieve maximum efficiency in the white region of the contour map.

In addition, depending on the characteristics or structure of the device, the third light emitting layer (EML) 334 of the third light emitting part 330 may be composed of two layers of a red light emitting layer and a green light emitting layer. The peak wavelength (λmax) of the light emitting region of the red light emitting layer may be in the range of 600 nm to 650 nm. The peak wavelength (λmax) of the light emitting region of the green light emitting layer may be in the range of 510 nm to 560 nm. Therefore, in this case, the light emitting region of the third light emitting layer (EML) 334 should emit light in the range of 510 nm to 650 nm to achieve maximum efficiency in the white region of the contour map.

In addition, according to the characteristics or structure of the device, the third light emitting layer (EML) 334 of the third light emitting part 330 is composed of two layers of a red light emitting layer and a yellow-green light emitting layer. can do. The peak wavelength (λmax) of the light emitting region of the red light emitting layer may be in the range of 600 nm to 650 nm. The peak wavelength (λmax) of the light emitting region of the yellow-green light emitting layer may be in the range of 510 nm to 580 nm. Therefore, in this case, the light emitting region of the third light emitting layer (EML) 334 should emit light in the range of 510 nm to 650 nm to achieve maximum efficiency in the white region of the contour map.

Therefore, as the third light emitting layer (EML) 334, a yellow-green light emitting layer, a yellow light emitting layer and a red light emitting layer, or a red light emitting layer and a green light emitting layer, or In the case of a yellow-green light emitting layer and a red light emitting layer, or a combination thereof, the peak wavelength (λmax) range of the light emitting region of the third light emitting layer (EML) 334 is 510 nm. to 650 nm. In this case, the maximum efficiency can be obtained in the white region of the contour map only when the light emitting region of the third light emitting layer (EML) 334 is 510 nm to 650 nm.

As described above, light is emitted at 440 nm to 480 nm, which is the peak wavelength (λmax) of the blue light emitting layer, and 540 nm to 575 nm, which is the peak wavelength (λmax) of the yellow-green light emitting layer. Therefore, the maximum efficiency can be obtained in the white area of the contour map. Therefore, it can be seen that the light emitting layer can achieve maximum efficiency by setting the emission position of the light emitting layers of the present invention to correspond to the peak wavelength of the light emitting layers. In addition, since the luminous efficiency of the light emitting layer is increased, panel efficiency, color reproducibility, and color viewing angle can be improved.

15 is a diagram showing light emission intensity according to a third embodiment of the present invention. 15 can be referred to as an EL spectrum.

In FIG. 15, the horizontal axis represents the wavelength region of light, and the vertical axis represents the emission intensity. The emission intensity is a numerical value expressed as a relative value based on the maximum value of the EL spectrum.

In FIG. 15, the embodiment (minimum position) is a part set to the minimum position when the emission positions of the light emitting layers are set. For example, when the light emitting position L1 of the first light emitting layer (EML) 314 is in the range of 100 nm to 150 nm from the first electrode 302, the minimum position is set to 100 nm.

The embodiment (maximum position) is a part set to the maximum position when the emission positions of the light emitting layers are set. For example, when the light emitting position L1 of the first light emitting layer (EML) 314 is in the range of 100 nm to 150 nm from the first electrode 302, the maximum position is set to 150 nm.

The embodiment (optimum position) is a part set as the light emitting position of the embodiment of the present invention. For example, when the light emitting position L1 of the first light emitting layer (EML) 314 is in the range of 100 nm to 150 nm from the first electrode 302, the light emitting position in the embodiment is set in the range of 100 nm to 150 nm will be.

As shown in FIG. 15, when the light emitting position of the present invention is out of the minimum position, a comparison with the optimal position is as follows. It can be seen that the emission intensity decreases in the range of 440 nm to 480 nm, which is the peak wavelength (λmax) range of blue light. In addition, it can be seen that the emission intensity decreases in the range of 540 nm to 575 nm, which is the peak wavelength (λmax) range of yellow-green light. In addition, it can be seen that the emission intensity significantly decreases in the range of the peak wavelength (λmax) of red light from 600 nm to 650 nm.

In addition, when the light emitting position of the present invention is out of the maximum position, a comparison with the optimal position is as follows. It can be seen that the emission intensity decreases in the range of 440 nm to 480 nm, which is the peak wavelength (λmax) range of blue light. In addition, it can be seen that the emission intensity decreases in the range of 540 nm to 575 nm, which is the peak wavelength (λmax) range of yellow-green light.

Therefore, it can be seen that the luminous intensity increases in the peak wavelength range of blue light when set to the optimal position of the present invention than when set to the minimum position or maximum position of the embodiment. In addition, it can be seen that the emission intensity increases in the peak wavelength range of yellow-green light when set to the optimal position of the present invention, compared to the case of setting to the minimum position or maximum position of the embodiment. In addition, it can be seen that the emission intensity increases in the peak wavelength range of red light when set to the optimum position of the present invention, compared to the case of setting to the minimum position or maximum position of the embodiment.

16 is a graph showing color viewing angles (Δu'v') according to viewing angles. As shown in FIG. 16, it is measured while looking at an angle from 0° to 15°, 30°, 45°, and 60° when viewed from the front.

In FIG. 16, the embodiment (minimum position) is a part set to the minimum position when the emission positions of the light emitting layers are set. For example, when the light emitting position L1 of the first light emitting layer (EML) 314 is in the range of 100 nm to 150 nm from the first electrode 302, the minimum position is set to 100 nm.

The embodiment (maximum position) is a part set to the maximum position when the emission positions of the light emitting layers are set. For example, when the light emitting position L1 of the first light emitting layer (EML) 314 is in the range of 100 nm to 150 nm from the first electrode 302, the maximum position is set to 150 nm.

The embodiment (optimum position) is a part set as the light emitting position of the embodiment of the present invention. For example, when the light emitting position L1 of the first light emitting layer (EML) 314 is in the range of 100 nm to 150 nm from the first electrode 302, the light emitting position in the embodiment is set in the range of 100 nm to 150 nm will be.

As shown in FIG. 16, when the light emitting position of the present invention is out of the minimum position, a comparison with the optimal position is as follows. In the case of the optimal position of the present invention, it can be seen that the color viewing angle (Δu'v') at a viewing angle of 60° of light emitted from the organic light emitting device is 0.016. In addition, it can be seen that when the light is out of the minimum position, the color viewing angle (Δu'v') is 0.070 at a viewing angle of 60° of the light emitted from the organic light emitting device. Therefore, when the color viewing angle Δu'v' is out of the minimum position, the color viewing angle (Δu'v') becomes 0.070 or more, and thus, a color change rate according to an angle or a color viewing angle defect occurs on the screen of the organic light emitting display device. Accordingly, the consumer can detect the color change according to the viewing angle.

In addition, when the light emitting position of the present invention is out of the maximum position, a comparison with the optimal position is as follows. In the case of the optimal position of the present invention, it can be seen that the color viewing angle (Δu'v') at a viewing angle of 60° of light emitted from the organic light emitting device is 0.016. Further, it can be seen that when the light is out of the maximum position, the color viewing angle (Δu'v') is 0.050 at a viewing angle of 60° of the light emitted from the organic light emitting device. Therefore, when the color viewing angle Δu'v' is out of the minimum position, the color viewing angle (Δu'v') becomes 0.050 or more, and thus, a color change rate according to an angle or a color viewing angle defect occurs on the screen of the organic light emitting display device. Accordingly, the consumer can detect the color change according to the viewing angle.

Therefore, when set to the optimal position of the present invention rather than to the minimum position or maximum position of the embodiment, it can be seen that the color viewing angle (Δu'v') at a viewing angle of 60° of light emitted from the organic light emitting device of the present invention is 0.016. there is. In the embodiment, since the color viewing angle (Δu'v') according to the viewing angle is small, the color change rate felt by the consumer according to the viewing angle can be improved. In addition, since the color viewing angle (Δu'v') of white is reduced, it may be advantageous to realize the same color regardless of viewing angle positions when implemented with an organic light emitting display device. In addition, it is possible to improve a color change rate according to an angle or a color viewing angle defect on a screen of an organic light emitting display device.

In addition, light emitting positions of the first light emitting layer, the second light emitting layer, and the third light emitting layer may be set to improve light emitting efficiency and a color viewing angle in consideration of a spectral change rate and a cavity peak of the light emitting layers.

A location of the second electrode may be in a range of 500 nm to 600 nm from the first electrode.

A light emitting position of the first light emitting layer may be in a range of 100 nm to 150 nm from the first electrode.

A light emitting position of the second light emitting layer may be in a range of 240 nm to 280 nm from the first electrode.

A light emitting position of the third light emitting layer may be in a range of 370 nm to 410 nm from the first electrode.

A color viewing angle (Δu'v') of light emitted from the organic light emitting device may be 0.016 or less at a 60° viewing angle.

17 is a cross-sectional view of an organic light emitting display device including an organic light emitting device according to an embodiment of the present invention, which includes organic light emitting devices according to the first, second and third embodiments of the present invention described above. it was used

As shown in FIG. 17, an organic light emitting display device 1000 according to the present invention includes a substrate 10, a thin film transistor (TFT), an overcoat layer 1150, a first electrode 102, a light emitting unit 1180, and and a second electrode (104). The thin film transistor (TFT) includes a gate electrode 1115, a gate insulating layer 1120, a semiconductor layer 1131, a source electrode 1133 and a drain electrode 1135.

In FIG. 17, the thin film transistor (TFT) is shown as an inverted staggered structure, but may be formed in a coplanar structure.

The substrate 10 may be made of glass, metal, or plastic.

A gate electrode 1115 is formed on the substrate 10 and connected to a gate line (not shown). The gate electrode 1115 is from the group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It may be a multi-layer made of any selected one or an alloy thereof.

The gate insulating layer 1120 is formed on the gate electrode 1115 and may be a silicon oxide film (SiOx), a silicon nitride film (SiNx), or a multilayer thereof, but is not limited thereto.

The semiconductor layer 1131 is formed on the gate insulating layer 1120, and includes amorphous silicon (a-Si), polycrystalline silicon (poly-Si), oxide semiconductor, or organic semiconductor. can be formed as When the semiconductor layer is formed of an oxide semiconductor, it may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO), but is not limited thereto. An etch stopper (not shown) may be formed on the semiconductor layer 1131 to protect the semiconductor layer 1131, but may be omitted depending on the configuration of the device.

The source electrode 1133 and the drain electrode 1135 may be formed on the semiconductor layer 1131 . The source electrode 1133 and the drain electrode 1135 may be formed of a single layer or multiple layers, and may include molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), or nickel (Ni). ), any one selected from the group consisting of neodymium (Nd) and copper (Cu), or an alloy thereof.

The protective layer 1140 is formed on the source electrode 1133 and the drain electrode 1135, and may be formed of a silicon oxide film (SiOx), a silicon nitride film (SiNx), or a multilayer thereof. Alternatively, it may be formed of acrylic resin, polyimide resin, etc., but is not limited thereto.

A color filter 1145 is formed on the first protective layer 1140, and although only one sub-pixel is shown in the drawing, the color filter 1145 is applied to regions of a red sub-pixel, a blue sub-pixel, and a green sub-pixel. is formed The color filter 1145 includes a red (R) color filter, a green (G) color filter, and a blue (B) color filter patterned for each sub-pixel. The color filter 1145 transmits only light of a specific wavelength among the white light emitted from the light emitting unit 1180 .

The overcoating layer 1150 is formed on the color filter 1145 and may be an acrylic resin, a polyimide resin, an oxide film (SiOx), a silicon nitride film (SiNx), or a multilayer thereof, but is limited thereto. It doesn't work.

The first electrode 102 is formed on the overcoating layer 1150 . The first electrode 102 is electrically connected to the drain electrode 1135 through a contact hole CH in a predetermined area of the protective layer 1140 and the overcoating layer 1150 . 11 shows that the drain electrode 1135 and the first electrode 1102 are electrically connected, but the source electrode ( 1133) and the first electrode 102 may be electrically connected.

A bank layer 1170 is formed on the first electrode 102 and defines a pixel area. That is, the bank layer 1170 is formed in a matrix structure at a boundary area between a plurality of pixels, so that a pixel area is defined by the bank layer 1170 . The bank layer 1170 may be formed of an organic material such as benzocyclobutene (BCB)-based resin, acryl-based resin, or polyimide resin. Alternatively, the bank layer 1170 may be formed of a photoresist containing a black pigment. In this case, the bank layer 1170 serves as a light blocking member.

The light emitting part 1180 is formed on the bank layer 1170 . As shown in the first, second and third embodiments of the present invention, the light emitting part 1180 includes the first light emitting part 110 formed on the first electrode 102 and the second light emitting part 1180. It consists of a part 120 and a third light emitting part 130 .

A second electrode 1104 is formed on the light emitting part 1180 .

Although not shown in FIG. 17 , an encapsulation portion may be formed on the second electrode 104 . The sealing part serves to prevent moisture from penetrating into the light emitting part 1180 . The encapsulation part may be formed of a plurality of layers in which inorganic materials different from each other are stacked, or a plurality of layers in which inorganic materials and organic materials are alternately stacked. And, an encapsulation substrate may be additionally configured on the encapsulation part. The encapsulation substrate may be made of glass, plastic, or metal. The encapsulation substrate may be adhered to the encapsulation unit by an adhesive.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and may be variously modified and implemented without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed according to the scope of the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100, 200, 300: white organic light emitting device
101, 201, 301: substrate
102, 202, 302: first electrode
104, 204, 304: second electrode
110, 210, 310: first light emitting unit
120, 220, 320: second light emitting unit
130, 230, 240: third light emitting unit
140, 240, 340: first charge generation layer
150, 250, 350: second charge generation layer
112, 212, 312: first hole transport layer
122, 222, 322: second hole transport layer
132, 232, 332: third hole transport layer
116, 216, 316: first electron transport layer
126, 226, 326: second electron transport layer
136, 236, 336: third electron transport layer
114, 214, 314: first light emitting layer
124, 224, 324: second light emitting layer
134, 234, 334: third light emitting layer

Claims (21)

a first light emitting unit including a first light emitting layer and disposed between the first electrode and the second electrode;
a second light emitting unit including a second light emitting layer and disposed above the first light emitting unit;
a third light emitting unit including a third light emitting layer and disposed above the second light emitting unit;
a first charge generation layer provided between the first light emitting part and the second light emitting part; and
A second charge generation layer provided between the second light emitting part and the third light emitting part,
The light emitting position of the first light emitting layer is in the range of 270 nm to 330 nm from the second electrode,
The light emitting position of the second light emitting layer is in the range of 150 nm to 200 nm from the second electrode,
The first light emitting layer and the second light emitting layer emit light of the same color as each other. According to claim 1,
The first light emitting layer and the second light emitting layer are positioned closer to the first electrode than the third light emitting layer. According to claim 1,
The organic light emitting device of claim 1 , wherein the first light emitting layer and the second light emitting layer are one of a blue light emitting layer, a dark blue light emitting layer, and a sky blue light emitting layer. According to claim 1,
Peak wavelengths (λmax) of the first light emitting layer and the second light emitting layer are in the range of 440 nm to 480 nm. According to claim 1,
The third light emitting layer emits light of a color different from that of the first light emitting layer and the second light emitting layer. According to claim 1,
The third light emitting layer is one of a yellow-green light emitting layer, a green light emitting layer, a red light emitting layer and a green light emitting layer, or a yellow light emitting layer and a red light emitting layer, or a yellow-green light emitting layer and a red light emitting layer, or a combination thereof. According to claim 1,
The peak wavelength (λmax) of the third light emitting layer is in the range of 510 nm to 580 nm or 510 nm to 650 nm. According to claim 1,
The first light-emitting layer and the second light-emitting layer are configured to be closer to the first electrode than to the second electrode. According to claim 1,
The light emitting position of the third light emitting layer is in the range of 20 nm to 80 nm from the second electrode. According to claim 1,
The position of the first electrode is in the range of 500 nm to 600 nm from the second electrode. According to claim 1,
The organic light emitting device having a color viewing angle (Δu'v') of 0.016 or less at a 60° viewing angle of light emitted from the organic light emitting device. According to claim 1,
wherein each of the first charge generation layer and the second charge generation layer includes an N-type charge generation layer and a P-type charge generation layer. According to claim 1,
wherein one of the first electrode and the second electrode includes a transflective electrode. According to claim 1,
The first light emitting unit further includes a first hole transport layer over the first electrode and a first electron transport layer over the first light emitting layer;
The second light emitting unit further includes a second hole transport layer over the first charge generating layer and a second electron transport layer over the second light emitting layer,
The organic light emitting device of claim 1 , wherein the third light emitting unit further includes a third hole transport layer on the second charge generation layer and a third electron transport layer on the third light emitting layer. 15. The method of claim 14,
The first light emitting unit further comprises a hole injection layer between the first electrode and the first hole transport layer. 15. The method of claim 14,
At least one of the first hole transport layer, the second hole transport layer, and the third hole transport layer is composed of two or more layers. 15. The method of claim 14,
At least one of the first electron transport layer, the second electron transport layer, and the third electron transport layer is composed of two or more layers. 15. The method of claim 14,
The third light emitting unit further comprises an electron injection layer on the third electron transport layer, the organic light emitting device. Board;
a thin film transistor provided on the substrate; and
It comprises an organic light emitting element provided on the thin film transistor,
The organic light emitting diode is an organic light emitting display device comprising the organic light emitting diode according to any one of claims 1 to 18. According to claim 19,
The organic light emitting display device further comprising a color filter disposed between the thin film transistor and the organic light emitting element. According to claim 19,
a protective layer on the thin film transistor;
a color filter on the protective layer; and
An organic light emitting display device further comprising an encapsulation layer on the second electrode.

Images