KR101901252B1 - Organic light emitting display device and method for fabricating the same - Google Patents

Abstract

The present invention relates to an organic light emitting diode (OLED) display device and a method of manufacturing the same, which can form a color SiO ₂ layer instead of a color filter to prevent deterioration of the organic light emitting layer and improve the stability of the OLED display cell, The apparatus includes a substrate; Each of the red, green, and blue subpixels includes a thin film transistor formed on the substrate; An insulating film formed on the entire surface of the substrate including the thin film transistor; An optical compensation layer formed on the insulating film; A color SiO ₂ layer formed on the optical compensation layer; A drain contact hole for selectively removing the insulating layer, the optical compensation layer, and the color SiO ₂ layer to expose the thin film transistor; And an OLED display cell formed on the color SiO ₂ layer and connected to the thin film transistor through the drain contact hole, the OLED display cell including a first electrode, a plurality of organic layers, and a second electrode sequentially stacked.

Description

Technical Field [0001] The present invention relates to an organic light emitting diode (OLED) display device and a method of manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting diode (OLED) display, and more particularly, to an OLED display capable of removing a color filter and forming a color SiO ₂ layer to realize color and a method of manufacturing the same.

The image display device that implements various information on the screen is a key technology in the era of information and communication, and it is progressing in the direction of being thinner, lighter, more portable, but higher performance. An organic light emitting display device which controls the amount of light emitted from the organic light emitting layer by using a flat panel display device has recently been spotlighted as a flexible display capable of bending due to space and convenience.

The organic light emitting diode display includes a thin film transistor array portion formed on a substrate, an organic light emitting display element disposed on the thin film transistor array portion, and a glass cap for isolating the organic light emitting display element from the external environment. The organic light emitting display utilizes an electroluminescent phenomenon in which an electric field is applied to the cathode and the anode formed at both ends of the organic light emitting layer to emit light by the binding energy when electrons and holes are injected into and transported from the organic light emitting layer, Electrons and holes emitted from the excited state fall from the excited state to the ground state.

Specifically, the organic light emitting display device has a plurality of subpixels arranged respectively in regions defined by intersections of a plurality of gate wirings and data wirings. Each of the subpixels receives a data signal from the data line when a gate pulse is supplied to the gate line, and generates light corresponding to the data signal.

Hereinafter, a general OLED display device will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a general organic light emitting diode display.

1, a general organic light emitting diode display includes a substrate 100 and a first electrode 170a, an organic light emitting layer 190, and a second electrode 170b, which are sequentially formed on the substrate 100 Emitting display cells.

Specifically, a thin film transistor is formed on the substrate 100. The thin film transistor includes a gate electrode 110a, a semiconductor layer 130 in which an active layer 130a and an ohmic contact layer 130b are sequentially stacked, and source and drain electrodes 140a and 140b. An insulating film 150a is formed to cover the thin film transistor, and a color filter 160 is formed on the insulating film 150a.

In particular, a white organic light emitting display (WOLED) is a device in which an organic light emitting layer 190 includes a plurality of organic layers to emit white light, and a color filter 160 formed on the insulating layer 150a Green, and blue color filters, respectively, so that light generated in the organic light emitting layer 190 can pass through the color filter 160 and emit various colors.

A planarization layer 150b is formed to cover the color filter 160 and a first electrode 170a is formed on the planarization layer 150b. At this time, the first electrode 170a is electrically connected to the drain electrode 140b through a drain contact hole (not shown) formed by selectively removing the insulating layer 150a and the planarization layer 150b.

A bank 180 having a bank hole for exposing a part of the first electrode 170a is formed on the planarization layer 150b to define a light emitting region and a first electrode 170a including the bank 180 is formed, And an organic light emitting layer 190 is formed on the entire surface. A second electrode 170b is formed on the entire surface of the organic light emitting layer 190. Holes are injected from the first electrode 170a and electrons are injected from the second electrode 170b and electrons injected into the organic light emitting layer 190 are injected into the organic light emitting layer 190 do. Further, although not shown, a capping layer may be further formed on the second electrode 170b to cap the OLED display cell.

However, in the general organic light emitting display as described above, since the color filter 160 is formed on the insulating layer 150a and the planarization layer 150b is further formed to cover the color filter 160 in order to planarize the color filter 160, . In addition, gas may be generated in the process of forming the color filter 160 and the planarization layer 150b, and the generated gas may flow into the organic light emitting layer 190, thereby reducing the life and reliability of the organic light emitting display cell.

Further, moisture adsorbed to the color filter 160 under the organic light emitting layer 190 may be introduced into the organic light emitting layer 190, causing problems such as dark spot and reduced lifetime. In addition, And the like.

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an organic light emitting diode display which can form a color SiO ₂ layer instead of a color filter to prevent deterioration of the organic light emitting layer, Method.

According to an aspect of the present invention, there is provided an OLED display including: a substrate; Each of the red, green, and blue subpixels includes a thin film transistor formed on the substrate; An insulating film formed on the entire surface of the substrate including the thin film transistor; An optical compensation layer formed on the insulating film; A color SiO ₂ layer formed on the optical compensation layer; A drain contact hole for selectively removing the insulating layer, the optical compensation layer, and the color SiO ₂ layer to expose the thin film transistor; And an OLED display cell formed on the color SiO ₂ layer and connected to the thin film transistor through the drain contact hole, the OLED display cell including a first electrode, a plurality of organic layers, and a second electrode sequentially stacked.

The plurality of organic layers emit white light.

The color SiO ₂ layer comprises SiO ₂ and a metal or metal compound.

The thickness of the color SiO ₂ layer is 0.1 탆 to 10 탆.

The metal corresponding to the red subpixel is selenium (Se) or cadmium (Cd).

The metal corresponding to the green subpixel is cobalt oxide (CoO).

The metal corresponding to the blue subpixel is copper (Cu) or cobalt (Co).

The optical compensation layer is formed of SiNx.

According to another aspect of the present invention, there is provided a method of manufacturing an organic light emitting device, including: forming a thin film transistor on each of red, green, and blue subpixels on a substrate; Forming an insulating film to cover the thin film transistor; Forming an optical compensation layer of SiNx on the insulating film; Forming a color SiO ₂ layer on the optical compensation layer; Selectively removing the insulating layer, the optical compensation layer, and the color SiO ₂ layer to form a drain contact hole exposing the thin film transistor; And forming an OLED display cell on the color SiO ₂ layer to be connected to the thin film transistor through the drain contact hole.

The forming of the OLED display cell may include forming a first electrode, Forming a plurality of organic layers on the first electrode; And forming a second electrode on the plurality of organic layers.

The plurality of organic layers emit white light.

The step of forming the color SiO ₂ layer uses a sputtering method.

The sputtering method uses a metal target and argon (Ar), nitrogen (N ₂ ), and oxygen (O ₂ ) gas.

In the sputtering method, the oxygen (O ₂ ) gas reacts with Si of the optical compensation layer to form SiO ₂ , and at the same time, the metal particles of the metal target are mixed with SiO ₂ to form a color SiO ₂ layer .

The metal target used in forming the color SiO ₂ layer of the red subpixel is selenium (Se) or cadmium (Cd).

The metal target used in forming the color SiO ₂ layer of the green subpixel is cobalt oxide (CoO).

The metal target used in forming the color SiO ₂ layer of the blue subpixel is copper (Cu) or cobalt (Co).

The organic light emitting diode display of the present invention and the method of fabricating the same of the present invention can form a color SiO ₂ layer without forming a color filter to realize white light generated from an organic light emitting layer formed of a plurality of organic layers in various colors.

Generally, since the color filter is formed of an organic material, the moisture adsorbed on the color filter may flow into the organic light emitting display cell, thereby decreasing the reliability and lifetime of the organic light emitting display cell. However, the color SiO ₂ layer of the present invention is an inorganic film formed by a sputtering method, which can realize the stability of the organic light emitting display cell and simplify the process at the same time.

1 is a sectional view of a general organic light emitting display device.
2 is a cross-sectional view of an organic light emitting display device according to the present invention.
3A to 3G are process cross-sectional views of an organic light emitting display device of the present invention.
4A is a graph comparing transmittances of a red SiO ₂ layer and a red color filter.
4B is a graph comparing transmittances of a green SiO ₂ layer and a green color filter.
4C is a graph comparing transmittances of the blue SiO ₂ layer and the blue color filter.

Hereinafter, an organic light emitting display device and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view of the organic light emitting diode display of the present invention.

2, the OLED display of the present invention includes a substrate 200, first and second electrodes 270a and 270b formed on the substrate 200, first and second electrodes 270a and 270b, 270b. The organic light emitting display cell has an organic light emitting layer (290). At this time, red, green, and blue subpixels are arranged in a matrix form on the substrate 200, and may further include white subpixels to improve brightness.

In particular, a color SiO ₂ layer 260 is formed for each sub-pixel below the organic light emitting display cell, so that white light emitted from a plurality of organic layers can be emitted as light of various colors.

More specifically, a plurality of subpixels are defined by a gate interconnection (not shown) and a data interconnection (not shown) perpendicularly intersecting the substrate 200, and a gate interconnection (not shown) and a data interconnection A thin film transistor is formed in the crossing region. The thin film transistor includes a gate electrode 210a, a source electrode 240a, a drain electrode 240b and a semiconductor layer 230 including an active layer 230a and an ohmic contact layer 230b sequentially stacked. At this time, the gate electrode 210a may protrude from a gate wiring (not shown) so as to supply a scan signal from a gate wiring (not shown), or may be defined as a part of a gate wiring (not shown).

The active layer 230a overlaps the gate electrode 210a with the gate insulating film 210 formed of an inorganic insulating material such as silicon oxide (SiOx), silicon nitride (SiNx) or the like interposed therebetween. The ohmic contact layer 230b formed on the active layer 230a serves to reduce electrical contact resistance between the source and drain electrodes 240a and 240b and the active layer 230a. The ohmic contact layer 230b corresponding to the interval between the source and drain electrodes 240a and 240b formed on the semiconductor layer 230 is removed to form a channel.

Specifically, the source electrode 240a is connected to a data line (not shown) to receive a pixel signal of a data line (not shown), and the drain electrode 240b faces the source electrode 240a with a channel interposed therebetween . An insulating film 250 is formed on the entire surface of the gate insulating film 210 including the thin film transistor and the data line (not shown) as an inorganic insulating material or an organic insulating material.

An optical compensation layer 300 is formed on the insulating layer 250. When the light generated from the organic light emitting layer 290 passes through the color SiO ₂ layer 260, which will be described later, for each sub-pixel according to the viewing angle, the optical compensation layer 300 has a different color light transmittance And is preferably formed of a silicon-based inorganic film such as SiNx or the like. In addition, it is preferable that the transmittance of the optical compensation layer 300 is 50% to 100% so that the light generated in the organic light emitting layer 290 is emitted through the substrate 200.

A color SiO ₂ layer 260 is formed on the optical compensation layer 300. The color SiO ₂ layer 260 serves to emit white light generated in the organic light emitting layer 290 in the form of light of various colors instead of the color filter. If the thickness of the color SiO ₂ layer 260 is too thick, the light transmittance It is preferable that the thickness of the color SiO ₂ layer 260 is 0.1 μm to 10 μm.

The color SiO ₂ layer 260 is formed by a sputtering method and the color SiO ₂ layer 260 is formed of a metal such as SiO ₂ and a metal or a metal compound such as a metal oxide, a metal nitride, a metal phosphide, a metal sulfide, ≪ / RTI > At this time, the metal is different for red, green, and blue subpixels.

Specifically, the color SiO ₂ layer 260 of the red subpixel includes SiO ₂ and selenium (Se) or SiO ₂ and cadmium (Cd), and emits red light when white light is incident. The color SiO ₂ layer 260 of the green subpixel includes SiO ₂ and cobalt oxide (CoO), and emits green light when white light is incident.

The color SiO ₂ layer 260 of the blue subpixel includes SiO ₂ and copper (Cu) or SiO ₂ and cobalt (Co), and emits blue light when white light is incident. At this time, copper (Cu) includes copper oxide (Cu ₂ O), copper oxide (CuO), and the like. Further, the white light passing through the white (W) sub-pixel in which the color SiO ₂ layer 260 is not formed emits white light as it is.

An OLED display cell including a first electrode 270a, an organic emission layer 290, and a second electrode 270b is formed on the color SiO ₂ layer 260. In this case, the first electrode 270a may be formed by using an anode, such as tin oxide (TO), indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc (Indium Tin Zinc Oxide) (ITZO), or the like.

A bank 280 having a bank hole for defining a light emitting region is formed on the first electrode 270a and an organic light emitting layer 290 is formed on the entire surface of the first electrode 270a including the bank 280. [ As described above, the organic light emitting layer 290 includes a plurality of organic layers to emit white light. The second electrode 270b is a cathode formed of a reflective metal such as aluminum to reflect the light generated from the organic emission layer 290 toward the first electrode 270a.

Although not shown, a hole injecting layer and a hole transporting layer may be further formed between the first electrode 270a and the organic light emitting layer 290. The hole injecting layer and the hole transporting layer may be formed by injecting holes . An electron injection layer and an electron transport layer may be further formed between the organic emission layer 290 and the second electrode 270b and electrons may be injected into the organic emission layer 290 through the electron injection layer and the electron transport layer .

When a voltage is applied between the first electrode 270a and the second electrode 270b, a hole from the first electrode 270a is electron-emitted from the second electrode 270b, And recombines in the organic light emitting layer 290 to form excitons. Then, the excitons and emit light to fall to a base state, and emits light corresponding to each color, SiO ₂ layer 260 by passing through the color SiO ₂ layer 260 of the organic light emitting display cell bottom.

The organic light emitting display of the present invention as described above forms a color SiO ₂ layer 260 instead of a color filter. In particular, the color SiO ₂ layer 260 is an inorganic film formed by a sputtering method, and can prevent deterioration of the organic light emitting layer, thereby realizing the stability of the organic light emitting display cell.

Hereinafter, a method of manufacturing an organic light emitting display according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3A to 3G are process cross-sectional views of the organic light emitting diode display of the present invention.

As shown in FIG. 3A, a thin film transistor is formed on a substrate 200. FIG. Specifically, a gate wiring (not shown) and a gate electrode 210a are formed on the substrate 200. A gate insulating layer 210 is formed so as to cover the gate electrode 210a and then a semiconductor layer 230 is formed on the gate insulating layer 210 and includes an active layer 230a and an ohmic contact layer 230b. Source and drain electrodes 240a and 240b, and a data line (not shown).

3B, an insulating layer 250 is formed on the entire surface of the gate insulating layer 210 including the source and drain electrodes 240a and 240b. The insulating film 250 is formed of an organic insulating material or an inorganic insulating material. Then, the optical compensation layer 300 is formed on the insulating film 250 with a silicon-based inorganic film such as SiNx or the like.

When the light generated from the organic light emitting layer 290, which will be described later, passes through the color SiO ₂ layer to be described later according to the viewing angle, the optical compensation layer 300 has a transmittance of the color SiO ₂ layer differs for each sub- Shift of the organic light emitting layer 290 is preferably 50% to 100% so that the light generated in the organic light emitting layer 290 is emitted through the substrate 200.

Next, as shown in FIG. 3C, a color SiO ₂ layer 260 is formed on the optical compensation layer 300 by using a sputtering apparatus. Specifically, when argon (Ar), nitrogen (N ₂ ), and oxygen (O ₂ ) gas are injected into a chamber in a high vacuum state and gas is accelerated by using an electric field, gas ions collide with the metal target, It comes off. At the same time, oxygen (O ₂ ) gas reacts with Si of the optical compensation layer to form SiO ₂ , and metal particles separated from the metal target and SiO ₂ are mixed to form a color SiO ₂ layer 260 Is formed.

When forming the color SiO ₂ layer 260 corresponding to the red subpixel, selenium (Se) or cadmium (Cd) is used as the metal target and a color SiO ₂ layer 260 corresponding to the green subpixel When forming, cobalt oxide (CoO) is used as a metal target. In forming the color SiO ₂ layer 260 corresponding to the blue subpixel, copper (Cu) or cobalt (Co) is used as a metal target.

3D, the insulating layer 250, the optical compensation layer 300, and the color SiO ₂ layer 260 are selectively removed to expose the drain electrode 240 b, and then, on the color SiO ₂ layer 260 And the organic light emitting display cell connected to the drain electrode 240b is formed. First, a first electrode 270a connected to the drain electrode 240b is formed. The first electrode 270a is formed by a deposition method such as a sputtering method. Then, as shown in FIG. 3E, the bank 280 having the bank hole for selectively exposing the first electrode 270a is formed.

3F, a solution process such as an ink jet, a nozzle coating, a spray coating, a roll printing, or the like is performed on the entire surface of the bank 280 including the bank holes, ) Method to form an organic light emitting layer 290 including a plurality of organic layers. 3G, the second electrode 270b is formed on the organic light emitting layer 290. Then, as shown in FIG.

Accordingly, excitons are formed by recombination of holes and electrons injected into the organic light emitting layer 290, light is emitted as the excitons fall to the ground state, and the light passes through the color SiO ₂ layer 260 under the organic light emitting display cell And emits light corresponding to the color SiO ₂ layer 260 formed in each sub-pixel.

Generally, color filters are formed of an organic substance is adsorbed moisture on the color filter enters cell OLED display, but may degrade the reliability, service life, etc. of the organic light-emitting display cells, the present invention is colored by a sputtering (Sputtering) method SiO ₂ layer The organic light emitting display cell 260 can be formed to realize the stability of the organic light emitting display cell, and the process can be simplified at the same time.

Hereinafter, the transmittance and efficiency of the organic light emitting diode display of the present invention using a color SiO ₂ layer and a general organic light emitting display using a color filter are compared as follows.

Figure 4a is a graph comparing the transmittance of the red SiO ₂ layer and a comparison of the transmittance of the red color filter graph, Figure 4b green SiO ₂ layer and the green color filter, and Fig. 4c is blue SiO ₂ layer and the transmittance of the blue color filter FIG.

4A, 4B, and 4C, the color filter and the color SiO ₂ layer do not largely differ in transmittance. That is, when a color filter is formed using an organic material, a general organic light emitting display having a color filter must further include a planarization layer to cover the color filter, and the gas generated in the process of forming the color filter and the planarization layer Emitting layer and the lifetime and reliability of the organic light-emitting display cell are deteriorated.

However, the organic light emitting display of the present invention can prevent the above-described problems and can secure the same transmittance as the organic light emitting display in which the color filter is formed.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

200: substrate 210: gate insulating film
210a: gate electrode 230: semiconductor layer
230a: active layer 230b: ohmic contact layer
240a: source electrode 240b: drain electrode
250: insulating film 260: colored SiO ₂ layer
270a: first electrode 270b: second electrode
280: bank 290: organic light emitting layer
300: optical compensation layer

Claims (17)

A thin film transistor located on the subpixel of the substrate and including a gate electrode, a source electrode, a drain electrode, and a semiconductor layer;
An insulating film disposed on the entire surface of the substrate including the thin film transistor;
An optical compensation layer which is disposed on the insulating film and prevents a color shift due to a viewing angle;
A color SiO ₂ layer on the optical compensation layer;
A drain contact hole penetrating the insulating layer, the optical compensation layer, and the color SiO ₂ layer to expose the drain electrode of the thin film transistor; And
And an organic light emitting display cell located on the color SiO ₂ layer and in contact with the drain electrode through the drain contact hole. The method according to claim 1,
Wherein the organic light emitting display cell includes a first electrode, a plurality of organic layers, and a second electrode sequentially stacked,
Wherein the plurality of organic layers emit white light. The method according to claim 1,
Wherein the color SiO ₂ layer comprises SiO ₂ and a metal or a metal compound. The method according to claim 1,
Wherein the thickness of the color SiO ₂ layer is 0.1 μm to 10 μm. The method of claim 3,
Wherein the subpixel of the substrate implements red, and the metal is selenium (Se) or cadmium (Cd). The method of claim 3,
Wherein the sub-pixel of the substrate is green, and the metal is cobalt oxide (CoO). The method of claim 3,
Wherein the sub-pixel of the substrate is blue, and the metal is copper (Cu) or cobalt (Co). The method according to claim 1,
Wherein the optical compensation layer comprises SiNx. Forming a thin film transistor including a gate electrode, a source electrode, a drain electrode and a semiconductor layer on the subpixels of the substrate;
Forming an insulating film to cover the thin film transistor;
Forming an optical compensation layer on the insulating film to prevent a color shift due to a viewing angle with SiNx;
Forming a color SiO ₂ layer on the optical compensation layer;
Selectively removing the insulating layer, the optical compensation layer, and the color SiO ₂ layer to form a drain contact hole exposing the drain electrode of the thin film transistor; And
And forming an organic light emitting display cell connected to the drain electrode through the drain contact hole on the color SiO ₂ layer. 10. The method of claim 9,
The forming of the OLED display cell may include forming a first electrode,
Forming a plurality of organic layers on the first electrode; And
And forming a second electrode on the plurality of organic layers. 11. The method of claim 10,
Wherein the plurality of organic layers emit white light. 10. The method of claim 9,
Wherein the step of forming the color SiO ₂ layer uses a sputtering method. 13. The method of claim 12,
Wherein the sputtering method uses a metal target and argon (Ar), nitrogen (N ₂ ), and oxygen (O ₂ ) gas. 14. The method of claim 13,
In the sputtering method, the oxygen (O ₂ ) gas reacts with Si of the optical compensation layer to form SiO ₂ , and at the same time, the metal particles of the metal target are mixed with SiO ₂ to form a color SiO ₂ layer Wherein the organic light-emitting layer is formed on the substrate. 14. The method of claim 13,
Wherein the subpixel of the substrate is red, and the metal target used to form the color SiO ₂ layer is selenium (Se) or cadmium (Cd). 14. The method of claim 13,
Wherein the subpixel of the substrate is green, and the metal target used in forming the color SiO ₂ layer is cobalt oxide (CoO). 14. The method of claim 13,
Wherein the subpixel of the substrate is blue, and the metal target used in forming the color SiO ₂ layer is copper (Cu) or cobalt (Co).

Images