KR20150047794A - Organic light emitting display panel and method for fabricating the same - Google Patents

Abstract

The present invention relates to: an organic electroluminescence display panel which efficiently extracts light, generated in an organic light emitting layer, and thus can increase light efficiency; and a method for manufacturing the same. According to an embodiment of the present invention, the organic electroluminescence display panel includes: a first electrode formed on a substrate; the organic light emitting layer which is formed on each red, green, and blue subpixel on the first electrode; a second electrode formed on the organic light emitting layer; a front side sealing layer formed on the second electrode layer to have an inorganic barrier layer and an organic barrier layer which are alternately arranged at least once; and at least one capping layer that is formed between the lowest layer, the closest to the second electrode, among a plurality of thin films included in the front side sealing layer and the second electrode. A capping layer of one among the red sub-pixel, the green sub-pixel, and the blue sub-pixel has the number of layers different from those of the rest of the subpixels. The top layer of a capping layer of one among the red sub-pixel, the green sub-pixel, and the blue sub-pixel contacts the lowest layer of the front side sealing layer and has a refractive index different from that of the lowest layer of the front side sealing layer.

Description

Technical Field [0001] The present invention relates to an organic electroluminescent display panel,

The present invention relates to an organic light emitting display panel capable of efficiently extracting light generated in an organic light emitting layer to improve light efficiency and a method of manufacturing the same.

2. Description of the Related Art Recently, various flat panel display devices capable of reducing weight and volume, which are disadvantages of cathode ray tubes (CRTs), are emerging. Examples of the flat panel display include a liquid crystal display, a field emission display, a plasma display panel, and an electro-luminescence (EL) display. Among these organic electroluminescent display devices, since self-luminous devices which emit light by themselves do not require a backlight, they are lightweight and thin, and have a simple process, a wide viewing angle, a high speed response and a high contrast ratio It is suitable as a next generation flat panel display.

In particular, an organic light emitting display device emits light by energy generated when holes from the anode electrode and electrons from the cathode electrode are combined in the light emitting layer to generate excitons that return to the ground state again.

Light generated in the organic light emitting layer of such an organic light emitting display can not be extracted to the outside and most of the light is lost due to total internal reflection and only about 1/4 of the light generated in the organic light emitting layer is emitted to the outside, have.

Therefore, in recent years, various methods for efficiently extracting the light generated in the organic light emitting layer and improving the light efficiency have been demanded.

In order to solve the above problems, the present invention provides an organic light emitting display panel capable of efficiently extracting light generated in an organic light emitting layer to improve light efficiency and a method of manufacturing the same.

According to an aspect of the present invention, there is provided an organic electroluminescent panel comprising: a first electrode formed on a substrate; An organic light emitting layer formed on the first electrode and formed on each of the red, green, and blue sub-pixels; A second electrode formed on the organic light emitting layer; A front sealing layer formed on the second electrode such that the inorganic barrier layer and the organic barrier layer are alternated at least once; And a capping layer formed between the second electrode and the lowermost layer closest to the second electrode among the plurality of thin films included in the front sealing layer, and wherein at least one of the red, green, and blue sub- The capping layer of the pixel is different in the number of layers from the capping layer of the remaining sub-pixels of the red, green and blue sub-pixels, and the top layer of the capping layer of any one of the red, Layer, and has a refractive index different from that of the lowermost layer of the front sealing layer.

According to an aspect of the present invention, there is provided a method of manufacturing an organic light emitting display panel, including: forming a first electrode on a substrate; Forming an organic light emitting layer on each of the red, green, and blue sub-pixels on the first electrode; Forming a second electrode on the organic light emitting layer; Forming at least one capping layer on the second electrode, wherein the capping layer has at least one of an inorganic barrier layer and an organic barrier layer alternating with the capping layer; The capping layer of any of the red, green, and blue sub-pixels has a different layer number from the capping layer of the red sub-pixel, the green sub-pixel, and the blue sub-pixel, The top layer of the capping layer of the pixel is in contact with the bottom layer of the front sealing layer and has a refractive index different from the bottom layer of the front sealing layer.

The capping layer of the green and blue sub-pixels includes a first capping layer and a second capping layer formed between the first capping layer and the lowermost layer of the front sealing layer, The first capping layer or the second capping layer, and the second capping layer has a refractive index lower than that of the lowermost layer of the first capping layer and the front sealing layer.

Wherein the lowermost layer is an inorganic barrier layer closest to the second electrode among the plurality of thin films included in the front sealing layer, has a refractive index of 1.3 to 3.1, the first capping layer has a refractive index of 1.3 to 3.1, And the second capping layer has a refractive index of 1.2 to 3.

And the thickness of the second capping layer is 40 to 100 nm.

The lowermost layer of the first capping layer and the front sealing layer may be formed of a material selected from the group consisting of polymers, SiO2, SiNx, ZnS, LiF, PA, PI, TeO2, WO3, V2O5, AlxOx, ZnSe, triamine derivatives, arylene diamine derivatives, CBP or alumina quinone (Alq3), and the second capping layer is formed of at least one of SiNx, SiOx, SiON, and LiF.

And a white sub-pixel formed by stacking a red light emitting layer of the red sub-pixel, a green light emitting layer of the green sub-pixel, and a blue light emitting layer of the blue sub-pixel, wherein the capping layer of the white sub- And a second capping layer formed between the first capping layer and the lowermost layer of the front sealing layer, wherein the second capping layer is lower than the lowermost layer of the first capping layer and the front sealing layer And has a refractive index.

The present invention provides a capping layer having different numbers of sub-pixels for different colors and having a refractive index different from that of the lowermost layer of the front sealing layer. Due to the difference in refractive index between the capping layer and the lowermost layer of the front sealing layer, light generated in the organic light emitting layer causes optical resonance between these interfaces, so that light generated in the organic light emitting layer can be easily emitted to the outside, The recall rate is improved.

1 is a cross-sectional view illustrating an organic light emitting display panel according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view for explaining the cap layer shown in FIG. 1 in detail.
3 is a view for explaining the efficiency of the organic light emitting display panel shown in FIG.
4 is a cross-sectional view illustrating an organic light emitting display panel according to a second embodiment of the present invention.
5 is a cross-sectional view illustrating an organic light emitting display panel according to a third embodiment of the present invention.
6A to 6D are cross-sectional views illustrating a method of manufacturing an organic light emitting display panel according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings and embodiments.

1 is a cross-sectional view showing an organic light emitting display panel according to the present invention.

The organic light emitting display panel shown in FIG. 1 includes a thin film transistor, a light emitting cell connected to the thin film transistor, a capping layer 130 formed to protect the light emitting cell, and a front sealing layer 140.

The thin film transistor includes a gate electrode 106, a drain electrode 110 connected to the first electrode 122 of the light emitting cell, a source electrode 108 facing the drain electrode 110, and a gate insulating film 112 interposed therebetween The source electrode 108 and the drain electrode 110 overlap the gate electrode 106 to form an ohmic contact with the active layer 114, the source electrode 108 and the drain electrode 110 which form a channel between the source electrode 108 and the drain electrode 110, And an ohmic contact layer (116) formed between the active layers (114).

On this thin film transistor, an inorganic protective film 118 of an inorganic insulating material and an organic protective film 128 of an organic insulating material are sequentially formed. The organic protective film 128 is formed to planarize the substrate 101 on which the thin film transistor is formed and the inorganic protective film 118 is formed on the interface between the gate insulating film 112 and the source and drain electrodes 108 and 110 and the organic protective film 128 Is formed to improve stability.

The light emitting cell includes a first electrode 122 formed on the organic protective layer 128, an organic light emitting layer 150 including a light emitting layer formed on the first electrode 122, a second electrode 126 formed on the organic light emitting layer 150, .

The organic light emitting layer 150 is formed in the bank hole 104 formed by the bank insulating film 102 formed so as to divide each sub-pixel. 2, the organic light emitting layer 150 includes a first hole transport layer 152 (HTL1), a second hole transport layer 154 (HTL2), a light emitting layer 156, an electron transport layer (ETL) 158 in order or in reverse order.

The first and second hole transporting layers 152 and 154 supply holes from the first electrode 122 to the light emitting layer 156 of each sub pixel. The first hole transporting layer 152 is formed in common to the red, green, and blue sub-pixels R_SP, G_SP, and B_SP. The second hole transport layer 154 is formed only on the red and green subpixels R_SP and G_SP except for the blue subpixel B_SP and thicker on the red subpixel R_SP than the green subpixel G_SP. Accordingly, the distance between the first electrode 122 of the blue sub-pixel B_SP and the blue (B) light emitting layer 156 is closest to the distance between the first electrode 122 of the red sub-pixel R_SP and the red The distance between the first electrode 122 of the green sub-pixel G_SP and the green (G) emission layer 156 is formed to have a medium distance. It is possible to optimize the vertical efficiency in each sub-pixel by constructively interfering the outgoing light for each of the sub-pixels.

In the light emitting layer 156, light is generated because the holes supplied through the first and second hole transporting layers 152 and 154 and the electrons supplied through the electron transporting layer 158 are recombined.

The electron transporting layer 158 supplies electrons from the second electrode 104 to the light emitting layer 156 of each sub-pixel.

The first electrode 122 is electrically connected to the drain electrode 110 of the thin film transistor through the inorganic contact layer 118 and the pixel contact hole 120 passing through the organic passivation layer 128. The first electrode 122 is formed in a structure in which an opaque conductive layer such as aluminum (Al) and a transparent conductive layer such as indium tin oxide (ITO) are stacked. The opaque conductive layer included in the first electrode 122 serves as a reflective electrode that is generated in the organic light emitting layer 150 and reflects light traveling toward the substrate 101 toward the second electrode 126.

The second electrode 126 is formed as a transflective electrode on the organic light emitting layer 150. The second electrode 126 allows the light generated in the organic light emitting layer 150 to be emitted upward through the second electrode 126. The second electrode 104 is formed of a metal, an inorganic material, a metal mixed layer, or a mixed metal or inorganic material, or a mixture thereof, and is formed as a single layer or a multilayer. At this time, when each layer is a mixed layer of a metal, an inorganic material, or a metal, the ratio thereof is 10: 1 to 1:10. The metal forming the second electrode 104 is formed of Ag, Mg, Yb, Li, or Ca, and the inorganic material is formed of Li ₂ O, CaO, LiF, or MgF ₂ , We can supply a lot.

The front sealing layer 140 serves to improve the reliability by blocking the infiltration of moisture or oxygen introduced from the outside. The front sealing layer 140 is formed by stacking at least one inorganic barrier layer 142, at least one organic barrier layer 144, an adhesive film 146, and a barrier film 148 .

At least one layer of the inorganic barrier layer 142 is formed at least once with the organic barrier layer 144 to primarily block external moisture or oxygen penetration. The at least one inorganic barrier layer 142 is formed of at least one of aluminum oxide (AlxOx), silicon oxide (SiOx), SiNx, SiON, and LiF.

At least one layer of the organic barrier layer 144 secondarily blocks the penetration of moisture or oxygen outside. In addition, the organic barrier layer 144 serves as a buffer to mitigate the stress between the respective layers due to warping of the organic light emitting display device, and enhances the planarization performance. The organic barrier layer 144 is formed of a polymer material such as acrylic resin, epoxy resin, polyimide, or polyethylene.

The barrier film 148 is bonded to the substrate 101 having the thin film transistor and the light emitting cell through the adhesive film 146 formed on the back surface of the barrier film 148 to seal the light emitting cell.

The plurality of thin film layers 142, 144, 146, and 148 contained in the front sealing layer 140 are formed to be thicker to several hundreds of 탆 thick than the capping layer 130, thereby not affecting the resonance phenomenon due to light interference.

The capping layer 130 generates maximum constructive interference for each wavelength of light generated in the organic light emitting layer 150, thereby efficiently emitting light generated in the organic light emitting layer 150 toward the outside. That is, the capping layer 130 reflects light of a certain intensity or less that can not transmit the capping layer 130 out of the light generated in the organic light emitting layer 150. At this time, the light that can not pass through the capping layer 130 is reflected at the interface between the capping layer 130 and the lowermost layer of the front sealing layer 140, is repeatedly reflected at the interface by the resonance effect, When a constructive interference with the light generated in the organic light emitting layer 124 occurs, the intensity of the light increases and then passes through the capping layer 130 again.

The capping layer 130 includes a first capping layer 132 formed in common to the red, green, and blue sub-pixels R_SP, G_SP, and B_SP, a green and blue sub-pixel G_SP except for the red sub- , And B_SP).

At this time, the second capping layer 134 formed on the green and blue sub-pixels G_SP and B_SP is formed to have a different refractive index from the first capping layer 132 and the front sealing layer 140 in order to obtain a resonance effect. do.

Specifically, the second capping layer 134 located between the first capping layer 132 and the front sealing layer 140 is formed to have a lower refractive index than the first capping layer 132 and the front sealing layer 140. At this time, the refractive indexes of the inorganic barrier layer 142 positioned at the lowermost portions of the first capping layer 132 and the front sealing layer 140 may be equal to or different from each other. That is, the second capping layer 134 is 1.2 to 3, and the refractive index of the lowermost inorganic barrier layer 142 and the first capping layer 132 is 1.3 to 3.1. The lowermost inorganic barrier layer 142 of the first capping layer 132 and the front sealing layer 140 may be formed of a material selected from the group consisting of SiO2, SiNx, ZnS, LiF, PA, PI, TeO2, WO3, V2O5, AlxOx, ZnSe, CBP or alumina quinone (Alq3), and the second capping layer 134 is formed of at least one of SiNx, SiOx, SiON, and LiF. For example, the first capping layer 132 has a refractive index of 1.8, the lowermost inorganic barrier layer 142 is formed of SiNx to have a refractive index of 1.8, and the second capping layer 134 is formed of LiF, Refractive index.

Accordingly, in the green and blue sub-pixels G_SP and B_SP, the interface between the first capping layer 132 having a high refractive index and the second capping layer 134 having a low refractive index and the second capping layer 134 having a low refractive index, And the interface of the lowermost inorganic barrier layer 142 having a high refractive index, optical resonance occurs in the light generated in the organic light emitting layer 150. Due to the optical resonance, the light generated in the organic light emitting layer 150 can be easily emitted to the outside, thereby improving the light efficiency.

3 and Tables 1 to 3 show simulation results for explaining the efficiency improvement effect of the organic light emitting display panel shown in FIG. 3 and Tables 1 through 3 show that the first capping layer 132 has a refractive index of 1.8 and the lowermost inorganic barrier layer 142 is formed of SiNx to have a refractive index of 1.8 and the second capping layer 134 has a refractive index of LiF Resulting in a structure having a refractive index of 1.4.

Red Rx = 0.665 standard LiF (nm) Lum CIE_x CIE_y Efficiency increase rate (%) 0 65.8 0.665 0.334 Ref. 20 61.2 0.665 0.334 93 40 57.25 0.665 0.334 87 60 54.35 0.665 0.335 83 80 55.6 0.665 0.334 84 100 58.9 0.664 0.335 90

Based on Green Gx = 0.24 LiF (nm) Lum CIE_x CIE_y Efficiency increase rate (%) 0 109.7 0.24 0.71 Ref. 20 104.5 0.24 0.705 95 40 104.9 0.24 0.7 96 60 111.4 0.24 0.7 103 80 121.4 0.24 0.7 111 100 127.7 0.24 0.7 116

By Blue By = 0.055 LiF (nm) Lum CIE_x CIE_y Efficiency increase rate (%) 0 8.21 0.136 0.055 Ref. 20 8.35 0.137 0.055 102 40 8.96 0.137 0.055 109 60 9.26 0.136 0.055 113 80 9.22 0.135 0.055 112 100 8.96 0.134 0.055 109

As shown in FIG. 3 and Tables 1 to 3, the efficiency (Cd / A) increases as the thickness of the second capping layer 134 in the green sub-pixel G_SP increases. The efficiency Cd / A in the structure including the first and second second capping layers 132 is increased in the blue sub-pixel B_SP than in the structure in which the second capping layer 134 is not provided. That is, the first and second capping layers 132 and 134 are formed in the green and blue sub-pixels G_SP and B_SP, and the first capping layer 132 is formed in the case where the second capping layer 134 is formed in the range of 40 to 100 nm. The efficiency (Cd / A) is improved as compared with the structure (LiF 0 nm) having only the active layer (LiF 0 nm).

On the other hand, in the red sub-pixel R_SP, when the first and second capping layers 132 and 134 are provided, the efficiency is reduced compared to the structure including only the first capping layer 132 (LiF 0 nm).

Accordingly, the organic light emitting display panel according to the first embodiment of the present invention includes a first capping layer 132 and a second capping layer 140 formed in a thickness of 40 to 100 nm in the green and blue sub-pixels G_SP and B_SP, The efficiency of the green and blue sub-pixels G_SP and B_SP is improved by 3 to 13% when only the first capping layer 132 is formed in the red sub-pixel G_SP.

In the present invention, the second capping layer 134 of the green sub-pixel G_SP and the second capping layer 134 of the blue sub-pixel B_SP are formed to have the same thickness for convenience of the process. In addition, as shown in Table 2, the second capping layer 134 of the green sub-pixel G_SP can achieve maximum efficiency at 100 nm and the second capping layer 134 of the blue sub-pixel B_SP can achieve maximum efficiency at 60 nm . Accordingly, the second capping layer 134 of the green sub-pixel G_SP may be formed thicker than the second capping layer 134 of the blue sub-pixel B_SP.

4 is a cross-sectional view illustrating an organic light emitting display panel according to a second embodiment of the present invention.

The organic light emitting display panel shown in FIG. 4 is different from the organic light emitting display panel shown in FIG. 2 in that a second capping layer 134 instead of the first capping layer 132 includes red, green, and blue sub-pixels R_SP, , And B_SP). Accordingly, detailed description of the same constituent elements will be omitted.

The capping layer 130 shown in FIG. 4 includes a first capping layer 132 formed on green and blue sub-pixels G_SP and B_SP except for a red sub-pixel R_SP, , G_SP, and B_SP).

At this time, the second capping layer 134 formed in common to the red, green and blue sub-pixels R_SP, G_SP and B_SP has a first capping layer 132 and a front sealing layer 140, As shown in FIG. Specifically, the second capping layer 134 located between the first capping layer 132 and the front sealing layer 140 is formed to have a lower refractive index than the first capping layer 132 and the front sealing layer 140. In this case, the refractive indexes of the lowermost inorganic barrier layer 142 of the first capping layer 132 and the front sealing layer 140 may be equal to or different from each other. That is, the second capping layer 134 is 1.2 to 3, and the refractive index of the lowermost inorganic barrier layer 142 and the first capping layer 132 is 1.3 to 3.1. The lowermost inorganic barrier layer 142 of the first capping layer 132 and the front sealing layer 140 may be formed of a material selected from the group consisting of SiO2, SiNx, ZnS, LiF, PA, PI, TeO2, WO3, V2O5, AlxOx, ZnSe, CBP or alumina quinone (Alq3), and the second capping layer 134 is formed of at least one of SiNx, SiOx, SiON, and LiF. For example, the first capping layer 132 has a refractive index of 1.8, the lowermost inorganic barrier layer 142 is formed of SiNx to have a refractive index of 1.8, and the second capping layer 134 is formed of LiF, Refractive index.

Accordingly, in the red sub-pixel R_SP, light generated in the red (G) light-emitting layer 15R between the interface of the second capping layer 134 having a low refractive index and the lowermost inorganic barrier layer 142 having a high refractive index is optically resonated . In the green and blue sub-pixels G_SP and B_SP, the interface between the first capping layer 132 having a high refractive index and the second capping layer 134 having a low refractive index and the second capping layer 134 having a low refractive index, The light generated in the green (G) and blue (B) light emitting layers 156 between the interfaces of the lowermost inorganic barrier layer 142 of high refractive index causes optical resonance.

Due to the optical resonance, the light generated in the organic light emitting layer 150 can be easily emitted to the outside, thereby improving the light efficiency.

5 is a cross-sectional view illustrating an organic light emitting display panel according to a third embodiment of the present invention.

The organic light emitting display panel shown in FIG. 5 has the same components as those of the organic light emitting display panel shown in FIG. 4, except that the white subpixel W_SP is further included. Accordingly, detailed description of the same constituent elements will be omitted.

5, the red (R) emission layer 156 of the red subpixel R_SP, the green emission layer 156 of the green (G) subpixel, and the green subpixel 156 of the blue subpixel B_SP And a blue (B) light emitting layer 156 are stacked and formed.

The capping layer 130 of such a white sub-pixel includes first and second capping layers 132 and 134 as well as green and blue sub-pixels G_SP and B_SP.

At this time, the second capping layer 134 formed in common to the red, green, blue and white sub-pixels R_SP, G_SP, B_SP and W_SP has a first capping layer 132 and a front sealing Layer 140 is formed to have a different refractive index. Specifically, the second capping layer 134 located between the first capping layer 132 and the front sealing layer 140 is formed to have a lower refractive index than the first capping layer 132 and the front sealing layer 140. In this case, the refractive indexes of the lowermost inorganic barrier layer 142 of the first capping layer 132 and the front sealing layer 140 may be equal to or different from each other. That is, the second capping layer 134 is 1.2 to 3, and the refractive index of the lowermost inorganic barrier layer 142 and the first capping layer 132 is 1.3 to 3.1. The lowermost inorganic barrier layer 142 of the first capping layer 132 and the front sealing layer 140 may be formed of a material selected from the group consisting of SiO2, SiNx, ZnS, LiF, PA, PI, TeO2, WO3, V2O5, AlxOx, ZnSe, CBP or alumina quinone (Alq3), and the second capping layer 134 is formed of at least one of SiNx, SiOx, SiON, and LiF. For example, the first capping layer 132 has a refractive index of 1.8, the lowermost inorganic barrier layer 142 is formed of SiNx to have a refractive index of 1.8, and the second capping layer 134 is formed of LiF, Refractive index.

Accordingly, in the red sub-pixel R_SP, light generated in the red (G) light-emitting layer 15R between the interface of the second capping layer 134 having a low refractive index and the lowermost inorganic barrier layer 142 having a high refractive index is optically resonated . In the green, blue, and white sub-pixels G_SP, B_SP, and W_SP, the interface between the first capping layer 132 having a high refractive index and the second capping layer 134 having a low refractive index, Light generated in the green (G), blue (B), and white (R + G + B = W) light emitting layers 156 between the interface of the light blocking layer 134 and the lowermost inorganic barrier layer 142 of high refractive index acts as an optical resonance .

Due to the optical resonance, the light generated in the organic light emitting layer 150 can be easily emitted to the outside, thereby improving the light efficiency.

6A to 6D are cross-sectional views illustrating a method of manufacturing an organic light emitting display panel according to the present invention. Here, the organic light emitting display panel shown in FIG. 4 will be described as an example.

6A, the first electrode 122 and the first and second hole transporting layers 152 and 154 are formed on the substrate 101 in such a manner that the red (R), green (G), and blue (B) The electron transport layer 158, and the second electrode 126 are sequentially formed.

Then, the shadow mask 136 having the openings corresponding to the green and blue sub-pixels G_SP, B_SP as shown in Fig. 6B is aligned on the substrate 101 on which the second electrode 126 is formed. A first capping layer 132 is formed on the green and blue sub-pixels G_SP and B_SP since the first capping material that has passed through the shadow mask 136 is deposited on the substrate 101. [

Then, the open mask 138 is aligned on the substrate 101 on which the first capping layer 132 is formed, as shown in FIG. 6C. A second capping layer 134 is formed over the red, green, and blue sub-pixels R_SP, G_SP, and B_SP since the second capping material that has passed through the open mask 138 is deposited on the substrate 101.

Then, a front sealing layer 140 is formed on the substrate 101 on which the second capping layer 134 is formed, as shown in FIG. 6D. At this time, the front sealing layer 140 has a structure in which at least one inorganic barrier layer 142, at least one organic barrier layer 144, an adhesive film 146, and a barrier film 148 are stacked .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Will be clear to those who have knowledge of.

122: first electrode 156: organic light emitting layer
126: second electrode 132,134: capping layer
140: front sealing layer

Claims (11)

A first electrode formed on the substrate;
An organic light emitting layer formed on the first electrode and formed on each of the red, green, and blue sub-pixels;
A second electrode formed on the organic light emitting layer;
A front sealing layer formed on the second electrode such that the inorganic barrier layer and the organic barrier layer are alternated at least once;
And a capping layer formed between the second electrode and the lowermost layer closest to the second electrode among the plurality of thin films included in the front sealing layer,
The capping layer of any one of the red, green, and blue sub-pixels is different from the capping layer of the remaining sub-pixels of the red, green, and blue sub-pixels,
Wherein an uppermost layer of the capping layer of one of the red, green, and blue sub-pixels is in contact with a lowermost layer of the front sealing layer and has a refractive index different from that of the lowermost layer of the front sealing layer. Emitting display panel. The method according to claim 1,
The capping layer of the green and blue sub-pixels includes a first capping layer and a second capping layer formed between the first capping layer and the lowermost layer of the front sealing layer,
The capping layer of the red sub-pixel includes the first capping layer or the second capping layer,
Wherein the second capping layer has a lower refractive index than the lowermost layer of the first capping layer and the front sealing layer. 3. The method of claim 2,
Wherein the lowermost layer is an inorganic barrier layer closest to the second electrode among the plurality of thin films included in the front sealing layer and has a refractive index of 1.3 to 3.1,
Wherein the first capping layer has a refractive index of 1.3 to 3.1,
Wherein the second capping layer has a refractive index of 1.2 to 3. < RTI ID = 0.0 > 11. < / RTI > The method of claim 3,
Wherein the thickness of the second capping layer is 40 to 100 nm. The method of claim 3,
The lowermost layer of the first capping layer and the front sealing layer may be formed of a material selected from the group consisting of polymers, SiO2, SiNx, ZnS, LiF, PA, PI, TeO2, WO3, V2O5, AlxOx, ZnSe, triamine derivatives, arylene diamine derivatives, CBP or alumina quinone (Alq3), < / RTI >
Wherein the second capping layer is formed of at least one of SiNx, SiOx, SiON, and LiF. 3. The method of claim 2,
And a white sub-pixel formed by stacking a red light emitting layer of the red sub-pixel, a green light emitting layer of the green sub-pixel, and a blue light emitting layer of the blue sub-
The capping layer of the white sub-pixel has the first capping layer and the second capping layer formed between the first capping layer and the lowermost layer of the front sealing layer,
Wherein the second capping layer has a lower refractive index than the lowermost layer of the first capping layer and the front sealing layer. The method according to claim 6,
Wherein the lowermost layer is an inorganic barrier layer closest to the second electrode among the plurality of thin films included in the front sealing layer and has a refractive index of 1.3 to 3.1,
Wherein the first capping layer has a refractive index of 1.3 to 3.1,
Wherein the second capping layer has a refractive index of 1.2 to 3. < RTI ID = 0.0 > 11. < / RTI > The method according to claim 6,
The lowermost layer of the first capping layer and the front sealing layer may comprise at least one of SiO2, SiNx, ZnS, LiF, PA, PI, TeO2, WO3, V2O5, AlxOx, ZnSe, triamine derivatives, arylene diamine derivatives, CBP or alumina quinone ),
Wherein the second capping layer is formed of at least one of SiNx, SiOx, SiON, and LiF. Forming a first electrode on a substrate;
Forming an organic light emitting layer on each of the red, green, and blue sub-pixels on the first electrode;
Forming a second electrode on the organic light emitting layer;
And at least one capping layer formed on the second electrode,
Forming a front sealing layer on the capping layer such that the inorganic barrier layer and the organic barrier layer alternate at least once;
The capping layer of any one of the red, green, and blue sub-pixels is different from the capping layer of the remaining sub-pixels of the red, green, and blue sub-pixels,
Wherein an uppermost layer of the capping layer of one of the red, green, and blue sub-pixels is in contact with a lowermost layer of the front sealing layer and has a refractive index different from that of the lowermost layer of the front sealing layer. A method of manufacturing a light emitting display panel. 10. The method of claim 9,
The capping layer of the green and blue sub-pixels includes a first capping layer and a second capping layer formed between the first capping layer and the lowermost layer of the front sealing layer,
The capping layer of the red sub-pixel includes the first capping layer or the second capping layer,
Wherein the second capping layer has a refractive index lower than that of the lowermost layer of the first capping layer and the front sealing layer. 11. The method of claim 10,
The lowermost layer of the first capping layer and the front sealing layer may be formed of a material selected from the group consisting of polymers, SiO2, SiNx, ZnS, LiF, PA, PI, TeO2, WO3, V2O5, AlxOx, ZnSe, triamine derivatives, arylene diamine derivatives, CBP or alumina quinone (Alq3), < / RTI >
Wherein the second capping layer is formed of at least one of SiNx, SiOx, SiON, and LiF.

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