KR101952191B1 - Organic Light Emitting Display Device and Method for Manufacturing The Same - Google Patents

Abstract

An organic light emitting display device according to an aspect of the present invention includes: an organic light emitting device formed on a first substrate; An antireflection layer formed on the second substrate in a matrix form; And a color refiner formed on the second substrate and formed on each pixel defined by the anti-reflection layer, wherein the first substrate and the second substrate are bonded to each other so as to face each other, and the organic light emitting element And is electrically connected to the antireflection layer.

Description

Technical Field [0001] The present invention relates to an organic light emitting display device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display and a method of manufacturing the same, and more particularly, to an active organic light emitting display and a method of manufacturing the same.

Recently, as the information society has developed, a light and thin flat panel display has been actively developed. Typical flat panel display devices include a liquid crystal display device and an organic light emitting diode display device. The organic electroluminescent display device does not need a separate light source such as a backlight used in a liquid crystal display device, and is superior in color reproduction rate to realize a thinner and clearer image.

An active type organic light emitting display device in which each subpixel is independently driven among the organic light emitting display devices includes unit pixels composed of three subpixels of red, green, and blue. Each subpixel is defined by intersecting gate lines and data lines, and is independently driven by a driving element including a separate thin film transistor.

Meanwhile, the organic light emitting display device is classified into a top emission type and a bottom emission type according to the emitting direction of light emitted from the subpixel. In the top emission type, light is emitted in a direction opposite to the thin film transistor. In the bottom emission type, light is emitted in the direction of the thin film transistor.

In the top surface emission type, a polarizer is attached on the upper substrate to prevent reflection of external light, which causes a disadvantage of lowering the light extraction efficiency.

1 is a cross-sectional view illustrating a portion of an organic light emitting display device of a top emission type among conventional active organic light emitting display devices (hereinafter, referred to as organic light emitting display devices).

1, an organic light emitting display includes a first substrate 101, a second substrate 102, an organic light emitting device 110, a black matrix 120, a color refiner 130, and a polarizing plate 140 ).

First, an organic light emitting device 110 is formed on a first substrate 101. The organic light emitting device 110 includes an anode electrode 111, a bank layer 112, an organic light emitting layer 113, and a cathode electrode 114 sequentially formed.

When electrons transferred from the cathode electrode 114, which is a common electrode, are transmitted through the anode electrode 111 and the organic light emitting layer 113, excitons are formed. At this time, the organic light emitting layer 113 The light is emitted by the band gap energy of the light.

Next, a black matrix 120 is formed on the second substrate 102, and a color refiner 130 is formed on a plurality of pixels defined by the black matrix 120. The hue of the white light emitted to the organic light emitting layer 113 is converted and emitted according to the hue of the color refiner 130.

Then, the polarizing plate 140 is formed on the second substrate 102, so that the contrast ratio of the emitted light can be improved and the external visibility can be improved.

When the reflection of external light is minimized by using the polarizer 140 as described above, only less than 45% of the light emitted from the organic light emitting layer 113 is transmitted, and the brightness is reduced by more than half. Accordingly, if more power is used to compensate for the reduced luminance, the lifetime of the organic light emitting layer 113 is reduced.

The polarizing plate 140 is generally an expensive component and has a high component cost compared to a simple reflection prevention function. Therefore, when the polarizing plate 140 is attached for the anti-reflection function, There are disadvantages.

In addition, when light leakage occurs in a space between the black matrix 120 and the cathode 114, it is impossible to accurately display gradations for each pixel.

An object of the present invention is to provide an organic electroluminescent display device capable of reducing manufacturing cost.

According to an aspect of the present invention, there is provided an organic light emitting display including: an organic light emitting diode formed on a first substrate; An antireflection layer formed on the second substrate in a matrix form; And a color refiner formed on the second substrate and formed on each pixel defined by the anti-reflection layer, wherein the first substrate and the second substrate are bonded to each other so as to face each other, and the organic light emitting element And is electrically connected to the antireflection layer.

According to another aspect of the present invention, there is provided a method of manufacturing an organic light emitting display, including: forming an organic light emitting diode on a first substrate; Forming an antireflection layer on the second substrate in a matrix form; Forming a color refiner on each of the pixels formed on the second substrate and defined by the anti-reflection layer; And bonding the first substrate and the second substrate such that the organic light emitting device and the antireflection layer are electrically connected to each other.

According to the present invention, the production cost can be reduced by replacing the black matrix of the organic electroluminescence display device with the antireflection layer to prevent the reflection of the external light while replacing the expensive polarizing plate.

In addition, according to the present invention, it is possible to prevent reflection of external light by forming an antireflection layer in a double layer, and to prevent emitted light emitted from the organic light emitting layer from mixing with emitted light emitted from neighboring sub pixels.

1 is a cross-sectional view of a general organic light emitting display device of the present invention;
2 is a cross-sectional view illustrating an organic light emitting display device according to an embodiment of the present invention;
3 is a cross-sectional view of an antireflective layer according to one embodiment of the present invention;
4 is a cross-sectional view illustrating an organic light emitting display device according to another embodiment of the present invention; And
5 is a cross-sectional view illustrating an antireflection layer according to another embodiment of the present invention.

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

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

2, an organic light emitting display according to an exemplary embodiment of the present invention includes a first substrate 201, a second substrate 202, an organic light emitting diode 210, an antireflection layer 220, And a color refiner 230.

First, a first substrate 201 and a second substrate 202 are prepared. An organic light emitting diode 210 is formed on the first substrate 201 and an antireflection layer 220 and a color refiner 230 are formed on the second substrate 202. The first substrate 201 and the second substrate 202 may be formed of glass, a transparent flexible material, or an opaque insulating material. The transparent flexible material may be formed of polyimide, polyetherimide (PEI), and polyethyeleneterephthalate (PET).

Next, an organic light emitting diode 210 is formed on the first substrate 201. [ The organic light emitting device 210 includes an anode 211, a bank layer 212, an organic light emitting layer 213, and a cathode 214.

First, the anode electrode 211 is formed on the first substrate 201. The anode electrode 211 of the organic electroluminescent display device, which is a current driving device, is formed of a material having a large work function so as to supply holes. For example, it may be formed of a conductive oxide having a high work function and a conductive property. The conductive oxide is mostly transparent and includes, for example, indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO) .

The anode electrode 211 is connected to a thin film transistor (not shown) at the bottom and connected to the organic light emitting layer 213 to supply holes from the thin film transistor to the organic light emitting layer 213. The thin film transistor may be a driving thin film transistor (TFT).

In general, a switching thin film transistor and a driving thin film transistor (TFT) are required to emit light according to image information of a data signal inputted according to a scan signal.

In a switching thin film transistor, when a scan signal is applied to a gate electrode extending in a gate line, a data signal is received from a source electrode extending in the data line, and the data signal is transferred to a gate electrode of the drive transistor.

In the driving thin film transistor, the holes transferred through the power supply line are transferred to the anode electrode 211 through the drain electrode by the received data signal, and the emission of the organic light emitting layer 213 of the corresponding pixel is controlled by the holes do.

Next, the bank layer 212 is formed on the anode electrode 211. The bank layer 212 overlaps the edge of the anode electrode 211 and defines an area where the anode electrode 211 contacts the organic light emitting layer 213. The region where the anode electrode 211 contacts the organic light emitting layer 213 is a light emitting region, and the bank layer 212 defines a light emitting region of each pixel.

Further, the bank layer 212 makes the light emission of the organic light emitting layer 213 uniform. Charges, including electrons and holes, tend to be distributed more at the junctions of the conductors. Also in the anode electrode 211, there is an apex in the edge region. When charges are added to the apex, more light is emitted from the organic light emitting layer 213 in the region corresponding to the apex, and less light is emitted in the other region. Nonuniformity may occur. However, since the bank layer 212 covers the edge region of the anode electrode 211, it is possible to prevent the anode electrode 211 from being in contact with the organic light emitting layer 213 even if charges are accumulated in the edge region, It is possible to prevent the lifetime of the organic light emitting layer 213 from being reduced.

Next, an organic light emitting layer 213 is formed on the anode electrode 211 and the bank layer 212. [ The organic light emitting layer 213 may emit white light as a single material and may include materials emitting red, green, and blue, and light emitted from the three materials may be mixed to form a white light Release.

Next, a cathode electrode 214 is formed on the organic light emitting layer 213. [ The cathode electrode 214 is formed to be transparent in the top emission type, so that light emitted from the organic emission layer 213 can be emitted to the outside. The cathode electrode 214 may be a kind of common electrode because it applies the same voltage to all the pixels. Thus, it can be formed as a single layer that covers the entire surface of the substrate without being patterned. In order to prevent a driving problem due to an increase in resistance, an auxiliary electrode may be connected to the upper or lower portion of the cathode electrode 214 to reduce the resistance.

The cathode electrode 214 may be formed of one of silver (Ag), magnesium (Mg), aluminum (Al), and copper (Cu), or may be formed of an alloy containing any one of them. Low metal and alloys thereof. In addition, the cathode electrode 214 may be formed as a thin film to allow light to be emitted to the outside, and may be formed thin to a thickness of several hundreds of angstroms (A) or less.

Next, the antireflection layer 220 is formed in a matrix form on the second substrate 202, and defines each pixel. The antireflection layer 220 includes a translucent metal layer 221, an intermediate layer 222, and an auxiliary electrode 223. The antireflection layer 220 is formed in electrical contact with the cathode electrode 214 in the region corresponding to the bank layer 212. In the upper emission type, the cathode 214 should be thinner than a few hundreds of angstroms (A) in order to improve luminance. However, if the thickness is lowered, the resistance of the cathode 214 may be increased to hinder the flow of electrons to the organic emission layer 213 have. Accordingly, the cathode electrode 214 may be in contact with the antireflection layer 220 to reduce the resistance by using the antireflection layer 220 as an auxiliary electrode.

The anti-reflection layer 220 is formed on the second substrate 202 before the color refiner 230 is formed, and the conventional black matrix functions to distinguish the color refiner 230 on a pixel-by-pixel basis. The black matrix is formed of a single layer containing chromium (Cr) or a black resin, while the antireflection layer 220 is formed of a plurality of layers including metal to prevent reflection of incident light. The detailed structure and anti-reflection principle of the antireflection layer 220 will be described in FIG.

Next, a color refiner 230 is formed on a pixel defined by the antireflection layer 220. The color refiner 230 is the same as the color filter of the liquid crystal display device. For example, a color refiner 230 of red, green, and blue is formed for each pixel, The white light emitted from the light emitting layer 213 is converted into one of the hues and emitted to the outside.

3 is a cross-sectional view illustrating an antireflection layer 220 according to an embodiment of the present invention.

3, the reflection ring layer 220 according to an embodiment of the present invention includes a translucent metal layer 221, an intermediate layer 222, and an auxiliary electrode 223.

First, a translucent metal layer 221 is formed on the second substrate 202. The semitransparent metal layer 221 is formed of any one selected from the group consisting of titanium (Ti), molybdenum (Mo), and chromium (Cr), and is formed to a thickness of 50 ANGSTROM to 200 ANGSTROM. Generally, when the materials are formed of a metal that does not transmit light or a thin film having a thickness of about 50 Å to 200 Å, the light is partially transmitted as if it is a sunglass or a polarizing plate that transmits light.

Next, an intermediate layer 222 is formed on the semitransparent metal layer 221. The intermediate layer 222 is preferably formed to have a thickness capable of setting the phase difference between the first reflected light and the second reflected light by? / 2.

The intermediate layer 222 may be formed of a transparent insulating material or may be formed of a conductive oxide. As the transparent insulating material, silicon nitride (SiNx) or silicon oxide (SiOx) can be used as an insulating layer or a protective layer. Indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and the like may be used as the conductive oxide. Since the semitransparent metal layer 221 is electrically connected to the auxiliary electrode 223 when the intermediate layer 222 is formed of a conductive oxide, it is possible to reduce the resistance of the cathode electrode 214 by only the auxiliary electrode 223 Can be obtained.

The auxiliary electrode 223 is formed on the intermediate layer 222 and is electrically connected to the cathode electrode 214 to lower the resistance of the cathode electrode 214. [

The auxiliary electrode 223 is formed thicker than the semitransparent metal layer 221 so as not to transmit light and includes any one selected from the group consisting of copper (Cu), molybdenum (Mo), and titanium (Ti) .

When the external light incident through the substrate 210 meets the semi-transparent metal layer 221, a part of the external light is reflected by the first external light L1. A part of which is absorbed by the translucent metal layer 221, and the rest is transmitted. A part of the transmitted external light is reflected from the auxiliary electrode 223 to the second external light L2. At this time, when the phase difference between the first external light L1 and the second external light L2 becomes? / 2 as shown in the figure, destructive interference occurs between them, and external light is lost. The thickness of the intermediate layer 222 is in the range of 500 Å to 3000 Å in order to cause destructive interference between the first external light L1 and the second external light L2.

It is important to prevent the reflection of external light among the role of the antireflection layer 220. However, if the transmittance of the internal light emitted from the organic emission layer 213 is lowered by the antireflection layer 220, the luminance decreases and the power consumption increases There are drawbacks to this. Accordingly, appropriate thickness control of the antireflection layer 320 is required.

For example, when the semitransparent metal layer 221, the intermediate layer 222, and the auxiliary electrode 223 are sequentially stacked to a thickness of 800 Å / 150 Å / 800 Å, the light transmittance is 44% , Respectively.

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

4, the organic light emitting display according to another embodiment of the present invention includes a first substrate 301, a second substrate 302, an organic light emitting diode 310, an antireflection layer 320, And a color refiner 330.

An organic light emitting device 310 is formed on a first substrate 301 and an antireflection layer 320 and a color refiner 230 are formed on a second substrate 302.

Next, the organic light emitting diode 310 includes an anode 311, a bank layer 312, an organic light emitting layer 313, and a cathode 314 sequentially formed, and the cathode 314 includes an antireflection layer 320, respectively.

Next, the antireflection layer 320 includes an outer semitransparent metal layer 321, an intermediate layer 322, an auxiliary electrode 323, and an inner semitransparent metal layer 324. In particular, the auxiliary electrode 323 is formed inside the intermediate layer 222 and is located at the same distance as the outer semitransparent metal layer 321 and the inner semitransparent metal layer 324.

The intermediate translucent metal layer 321, the intermediate layer 222 and the auxiliary electrode 323 form an antireflection structure against external light and the internal translucent metal layer 324, the intermediate layer 222 and the auxiliary electrode 323 form an anti- Thereby forming an anti-reflection structure.

That is, the antireflection layer 320 is formed in a double structure in the direction of the second substrate 302 and the direction of the cathode electrode 314. The anti-reflection structure in the direction of the second substrate 302 prevents reflection of external light incident from the outside of the second substrate 302, and the anti-reflection structure in the direction of the cathode electrode 214 absorbs the internal light emitted from each pixel , The emitted light may be reflected to the organic light emitting layer 313 of a neighboring pixel or may prevent a light leakage phenomenon through a color refiner 230 of a neighboring pixel. A more detailed reflection prevention principle will be described with reference to FIG.

5 is a cross-sectional view illustrating an antireflection layer 320 according to another embodiment of the present invention.

5, the antireflection layer 320 according to an embodiment of the present invention includes an outer semitransparent metal layer 321, an intermediate layer 322, an auxiliary electrode 323, and an inner semitransparent metal layer 324 .

First, an outer translucent metal layer 321 is formed on the second substrate 302. The translucent metal layer 321 is formed of any one of the group including titanium (Ti), molybdenum (Mo), and chromium (Cr), and is formed to have a thickness of 50 Å to 200 Å so that light can be partially transmitted.

Next, an intermediate layer 322 is formed on the outer semitransparent metal layer 321. The intermediate layer 322 is preferably formed to have a thickness capable of setting the phase difference between the first reflected light and the second reflected light by? / 2.

The intermediate layer 322 may be formed of a transparent insulating material or may be formed of a conductive oxide. Silicon nitride (SiNx) or silicon oxide (SiOx) may be used as the transparent insulating material. Indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and the like may be used as the conductive oxide. Since the semitransparent metal layer 321 is electrically connected to the auxiliary electrode 323 when the intermediate layer 322 is formed of a conductive oxide, the effect of reducing the resistance of the cathode electrode 314 by using only the auxiliary electrode 323 Can be obtained. Further, since more conductive layers are formed than the antireflection layer 220 shown in FIG. 3, it can be more effective in solving the problem of reducing the resistance of the cathode electrode 314 in the top emission type.

Next, the auxiliary electrode 323 is formed on the intermediate layer 322, and is electrically connected to the cathode electrode 314, so that the resistance of the cathode electrode 314 can be lowered.

The auxiliary electrode 223 may include any one selected from the group consisting of copper (Cu), molybdenum (Mo), and titanium (Ti), which are commonly used for metal wiring. In addition, the auxiliary electrode 323 may be thicker than the outer semitransparent metal layer 321 so that the thickness of the auxiliary electrode 323 may be set so that external light is not transmitted. It is necessary to reflect all the external light through the auxiliary electrode 323, thereby preventing reflection of external light.

When the external light incident through the substrate 210 meets the external translucent metal layer 321, a part of the external light is reflected by the first external light L1 , A part of which is absorbed by the outer semitransparent metal layer 321, and the rest is transmitted. A part of the transmitted light is reflected from the auxiliary electrode 323 to the second external light L2. At this time, when the phase difference between the first external light L1 and the second external light L2 becomes? / 2 as shown in the figure, destructive interference occurs between them, and the reflected light disappears. The thickness of the intermediate layer 322 between the outer semitransparent metal layer 321 and the auxiliary electrode 323 is in the range of 50 Å to 3000 Å in order to cause destructive interference with the first and second external lights L1 and L2.

When the inner light emitted from the organic light emitting layer 313 encounters the inner semitransparent metal layer 324, a part of the light is reflected by the first inner light E1 , A part of which is absorbed by the inner translucent metal layer 324, and the rest is transmitted. A part of the transmitted internal light is reflected from the auxiliary electrode 323 to the second internal light E2. At this time, when the phase difference between the first internal light E1 and the second internal light E2 becomes? / 2 as shown in the figure, destructive interference occurs between them, and the internal light is extinguished. The thickness of the intermediate layer 322 between the inner semitransparent metal layer 321 and the auxiliary electrode 323 is in the range of 50 Å to 3000 Å in order to cause destructive interference between the first internal light E1 and the second internal light E2.

The antireflection layer 320 can prevent external light from being reflected to improve external visibility and prevent the problem that the antireflection layer 320 is not formed in the light emitting area and therefore the luminance is lowered and the power consumption is increased accordingly.

The antireflection layer 320 may further include an inner semi-transparent metal layer 324 and an intermediate layer 322 between the auxiliary electrode 323 and the cathode electrode 314 to prevent reflection of external light, 313, thereby preventing inter-pixel light leakage. By preventing inter-pixel light leakage, it is more effective in manufacturing a high-resolution organic light emitting display device in which the size of a pixel becomes smaller as the number of pixels increases.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

201: first substrate 202: second substrate
210: organic light emitting element 211: anode electrode
212: bank layer 213: organic light emitting layer
214: cathode electrode 220: antireflection layer
221: translucent metal layer 222: middle layer
223: auxiliary electrode 230: colored refiner

Claims (14)

An organic light emitting element formed on the first substrate;
An antireflection layer formed on the second substrate in a matrix form; And
And a color refiner formed on the second substrate and formed in each pixel defined by the anti-reflection layer,
Wherein the first substrate and the second substrate are bonded to each other so as to face each other, the organic light emitting device is electrically connected to the antireflection layer,
The anti-
A translucent metal layer formed on the second substrate;
An intermediate layer formed on the semitransparent metal layer; And
And an auxiliary electrode formed on the intermediate layer. The method according to claim 1,
Wherein the organic light emitting diode includes a cathode electrode, and the cathode electrode is electrically connected to the auxiliary electrode. The method according to claim 1,
Wherein the semitransparent metal layer reflects and transmits external light and the first external light reflected by the translucent metal layer and the second external light reflected by the auxiliary electrode disappear due to destructive interference. The method of claim 3,
Wherein the intermediate layer is formed between the semitransparent metal layer and the auxiliary electrode, and the intermediate layer sets the phase difference between the first external light and the second external light to? / 2. The method according to claim 1,
Wherein the intermediate layer is formed of a transparent conductive oxide, and electrically connects the semitransparent metal layer and the auxiliary electrode. An organic light emitting element formed on the first substrate;
An antireflection layer formed on the second substrate in a matrix form; And
And a color refiner formed on the second substrate and formed in each pixel defined by the anti-reflection layer,
Wherein the first substrate and the second substrate are bonded to each other so as to face each other, the organic light emitting device is electrically connected to the antireflection layer,
The organic light emitting device includes a cathode electrode,
Wherein the anti-reflection layer comprises an outer translucent metal layer for reflecting and transmitting external light, and an inner translucent metal layer for reflecting and transmitting internal light emitted from the organic light emitting layer, wherein the cathode electrode is electrically connected to the internal semi- Display device. The method according to claim 6,
Wherein the first external light reflected by the external translucent metal layer and the second external light reflected by the auxiliary electrode are destroyed due to destructive interference, Wherein the first internal light reflected by the inner semitransparent metal layer and the second internal light reflected by the auxiliary electrode disappear due to destructive interference. 8. The method of claim 7,
Further comprising an intermediate layer formed between the outer semitransparent metal layer and the auxiliary electrode and between the inner semitransparent metal layer and the auxiliary electrode, wherein the intermediate layer sets a phase difference between the first external light and the second external light to? / 2 And a phase difference between the first internal light and the second internal light is set to? / 2. 9. The method of claim 8,
Wherein the intermediate layer is formed of a transparent conductive oxide and electrically connects the outer semitransparent metal layer and the inner semitransparent metal layer to the auxiliary electrode. The method according to claim 1,
Wherein the organic light emitting diode further comprises a bank layer formed at a boundary of the pixel, and the antireflection layer and the organic light emitting diode are electrically connected in a region corresponding to the bank layer. Forming an organic light emitting device on the first substrate;
Forming an antireflection layer on the second substrate in a matrix form;
Forming a color refiner on each of the pixels formed on the second substrate and defined by the anti-reflection layer; And
And bonding the first substrate and the second substrate such that the organic light emitting device and the anti-reflection layer are electrically connected to each other,
The step of forming the anti-
Forming a translucent metal layer on the second substrate;
Forming an intermediate layer on the semi-transparent metal layer; And
And forming an auxiliary electrode on the intermediate layer. 12. The method of claim 11,
The forming of the organic light-
Forming an anode electrode on the first substrate;
Forming an organic light emitting layer on the anode electrode; And
And forming a cathode electrode on the organic light emitting layer. 12. The method of claim 11,
The forming of the organic light-
Forming a bank layer at the boundary of the pixel,
Wherein the first substrate and the second substrate are bonded together such that the antireflection layer and the bank layer correspond to each other. delete

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