KR20130075141A - Organic light emitting display device and method for fabricating the same - Google Patents

Abstract

PURPOSE: An organic light emitting display device and a manufacturing method thereof are provided to convert white light from an organic light emitting layer composed of a plurality of organic layers into light with various colors by forming a color SiO2 layer instead of a color filter. CONSTITUTION: An insulation layer (250) is formed on the front side of a substrate (200) including a thin film transistor. A light compensation layer (300) is formed on the insulation layer. A color SiO2 layer (260) is formed on the light compensation layer. The color SiO2 layer includes SiO2 or metal compounds. An organic light emitting display cell includes a first electrode (270a), a plurality of organic light emitting layers (290), and a second electrode (270b).

Description

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

The present invention relates to an organic light emitting diode display, and more particularly, to an organic light emitting diode display and a method of manufacturing the same, which can implement color by removing a color filter and forming a color SiO ₂ layer.

Video display devices that implement a variety of information as screens are core technologies of the information and communication era, and are being developed in a direction of thinner, lighter, portable and high performance. BACKGROUND ART As a flexible display that can be bent in pursuit of space and convenience is demanded, an organic light emitting display device that controls the amount of light emitted from the organic light emitting layer as a flat panel display device has recently been in the spotlight.

The organic light emitting diode display includes a thin film transistor array unit formed on a substrate, an organic light emitting display element disposed on the thin film transistor array unit, and a glass cap for isolating the organic light emitting display element from an external environment. The organic light emitting diode display uses an electroluminescence phenomenon that emits light by the binding energy when the electrons and holes are injected and transferred into the organic light emitting layer by combining an electric field to the cathodes and the anodes formed at both ends of the organic light emitting layer to combine with each other. The electrons and holes that make up fall from the excited state to the ground state and emit light.

In detail, the organic light emitting diode display includes a plurality of subpixels arranged in regions defined by intersections of the plurality of gate lines and the data lines. Each of the subpixels receives a data signal from the data line when the gate pulse is supplied to the gate line to generate 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 display device.

As shown in FIG. 1, a general organic light emitting display device includes a substrate 100 and a first electrode 170a, an organic emission layer 190, and a second electrode 170b that are sequentially formed on the substrate 100 and stacked on the substrate 100. It includes an organic light emitting display cell.

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

In particular, the white organic light emitting display device (WOLED) includes an organic light emitting layer 190 including a plurality of organic layers to emit white light, and the color filter 160 formed on the insulating layer 150a is formed. Each of the light emitting diodes includes red, green, and blue color filters, and light generated in the organic emission layer 190 may pass through the color filter 160 and emit various colors.

The planarization layer 150b is formed to cover the color filter 160, and the first electrode 170a is formed on the planarization layer 150b. In this case, 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.

In addition, a bank 180 having a bank hole exposing a part of the first electrode 170a is formed on the planarization layer 150b and the first electrode 170a including the bank 180 is formed. The organic emission layer 190 is formed on the entire surface. The second electrode 170b is formed on the entire surface of the organic emission layer 190. The organic light emitting layer 190 emits light by the binding energy when holes are injected from the first electrode 170a and electrons are injected from the second electrode 170b, and holes and electrons injected into the organic light emitting layer 190 combine with each other. do. Although not shown, a capping layer may be further formed on the second electrode 170b to cap the organic light emitting display cell.

However, in the general organic light emitting diode display as described above, since the color filter 160 is formed on the insulating film 150a, the planarization layer 150b is additionally formed to cover the color filter 160 in order to planarize the process. This gets complicated. 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 to reduce the lifespan and reliability of the organic light emitting display cell.

In addition, moisture adsorbed to the color filter 160 under the organic light emitting layer 190 may flow into the organic light emitting layer 190, which may cause problems such as dark spots and reduced lifespan. Problems may occur.

The present invention has been made in view of the above-described problems, an organic light emitting display device and a manufacture thereof, which can form a color SiO ₂ layer instead of a color filter, thereby preventing degradation of the organic light emitting layer and improving stability of the organic light emitting display cell. To provide a way.

An organic light emitting display device of the present invention for achieving the above object is a substrate; Each of the red, green, and blue subpixels may include a thin film transistor formed on the substrate; An insulating film formed on the entire surface of the substrate including the thin film transistor; A light compensation layer formed on the insulating film; A color SiO ₂ layer formed on the light compensation layer; A drain contact hole exposing the thin film transistor by selectively removing the insulating layer, the light compensation layer, and the color SiO ₂ layer; And an organic light emitting display cell formed on the color SiO ₂ layer and connected to the thin film transistor through the drain contact hole and including a first electrode, a plurality of organic layers, and a second electrode that are sequentially stacked.

The plurality of organic layers emit white light.

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

The thickness of the colored SiO ₂ layer is 0.1 μm to 10 μm.

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 light compensation layer is formed of SiNx.

In addition, the manufacturing method of the organic light emitting device of the present invention for achieving the same object comprises the steps of forming a thin film transistor on each of the red, green, blue sub-pixel on the substrate; Forming an insulating film to cover the thin film transistor; Forming a light compensation layer of SiNx on the insulating film; Forming a colored SiO ₂ layer on the light compensation layer; Selectively removing the insulating layer, the light compensation layer, and the color SiO ₂ layer to form a drain contact hole exposing the thin film transistor; And forming an organic light emitting 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 organic light emitting 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.

Forming the colored SiO ₂ layer uses a sputtering method.

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

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

The metal target used in forming the colored SiO ₂ layer of the red sub-pixel is selenium (Se) or cadmium (Cd).

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

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

As described above, the organic light emitting diode display and a method of manufacturing the same may implement white light generated in an organic light emitting layer formed of a plurality of organic layers by forming a color SiO ₂ layer without forming a color filter in various colors.

In general, since the color filter is formed of an organic material, moisture adsorbed to the color filter flows into the organic light emitting display cell, thereby reducing the reliability, lifespan, and the like 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, it is possible to implement the stability of the organic light emitting display cell and at the same time simplify the process.

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

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

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

As illustrated in FIG. 2, the organic light emitting diode display of the present invention is formed on the substrate 200 and the substrate 200, and includes first and second electrodes 270a and 270b, and first and second electrodes 270a and 270b. And an organic light emitting display cell having an organic light emitting layer 290 therebetween. In this case, red, green, and blue subpixels are arranged in a matrix on the substrate 200, and may further include white subpixels to improve luminance.

In particular, a color SiO ₂ layer 260 is formed in each subpixel under the organic light emitting display cell, thereby emitting white light emitted from a plurality of organic layers as light of various colors.

In detail, a plurality of subpixels are defined by vertical crossings of gate lines (not shown) and data lines (not shown) on the substrate 200, and gate lines (not shown) and data lines (not shown) intersect. The thin film transistor is formed in the cross 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 that are sequentially stacked. In this case, the gate electrode 210a may be formed to protrude from the gate line (not shown) to supply a scan signal from the gate line (not shown), or may be defined as a partial region of the gate line (not shown).

The active layer 230a overlaps the gate electrode 210a with a gate insulating film 210 formed of an inorganic insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx) interposed therebetween. The ohmic contact layer 230b formed on the active layer 230a reduces the 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 spaced apart intervals of 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 the data line (not shown) to receive a pixel signal of the data line (not shown), and the drain electrode 240b faces the source electrode 240a with a channel interposed therebetween. Is formed. The insulating film 250 is formed of an inorganic insulating material or an organic insulating material on the entire gate insulating film 210 including the thin film transistor and the data line (not shown).

The light compensation layer 300 is formed on the insulating film 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 subpixel according to the viewing angle, the light compensation layer 300 may have different light transmittances. It is preferable to be formed of a silicon-based inorganic film, such as SiNx, in order to prevent the occurrence. In addition, the light compensation layer 300 preferably has a transmittance of 50% to 100% so that light generated in the organic light emitting layer 290 is emitted through the substrate 200.

The color SiO ₂ layer 260 is formed on the light compensation layer 300. The color SiO ₂ layer 260 is to emit white light generated in the organic light emitting layer 290 as light of various colors in place of the color filter. When the thickness of the color SiO ₂ layer 260 is too thick, the light transmittance may be reduced. Since the thickness is lowered, the thickness of the colored SiO ₂ layer 260 is preferably 0.1 μm to 10 μm.

The colored SiO ₂ layer 260 is formed by a sputtering method, and the colored SiO ₂ layer 260 is formed of a metal such as metal oxide, metal nitride, metal phosphide, metal sulfide, metal chloride, etc., with SiO ₂ and the metal or metal compound. Compound. In this case, the metal is different for each of the 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 colored 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 cuprous oxide (Cu ₂ O), cupric oxide (CuO), and the like. In addition, 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 organic light emitting 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 is an anode, and tin oxide (TO), indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc It is formed of a transparent conductive material such as oxide (Indium Tin Zinc Oxide (ITZO)).

A bank 280 having a bank hole for defining a light emitting area 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 formed of a reflective metal material such as aluminum (Al) as a cathode, and reflects light generated in the organic emission layer 290 toward the first electrode 270a.

Although not shown, a hole injection layer and a hole transport layer may be further formed between the first electrode 270a and the organic light emitting layer 290, and the hole injection layer and the hole transport layer are well injected into the organic light emitting layer 290. It is to make it possible. In addition, an electron injection layer and an electron transporting layer may be further formed between the organic emission layer 290 and the second electrode 270b, and the electron injection layer and the electron transporting layer may be used to inject electrons into the organic emission layer 290 well. .

In the organic light emitting display cell as described above, when a voltage is applied between the first electrode 270a and the second electrode 270b, holes are formed from the first electrode 270a and electrons are discharged from the second electrode 270b. Is injected to recombine in the organic emission layer 290 to generate 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 diode display of the present invention as described above forms the color SiO ₂ layer 260 instead of the color filter. In particular, the color SiO ₂ layer 260 is an inorganic film formed by a sputtering method, and may prevent stability of the organic light emitting layer to implement stability of the organic light emitting display cell.

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

3A to 3G are cross-sectional views illustrating a process of the OLED display according to the present invention.

As shown in FIG. 3A, a thin film transistor is formed on the substrate 200. Specifically, a gate wiring (not shown) and a gate electrode 210a are formed on the substrate 200. After the gate insulating film 210 is formed to cover the gate electrode 210a, the semiconductor layer 230 in which the active layer 230a and the ohmic contact layer 230b are sequentially stacked on the gate insulating film 210, Source, drain electrodes 240a and 240b and data lines (not shown) are formed.

As illustrated in FIG. 3B, an insulating film 250 is formed over the gate insulating film 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. The light compensation layer 300 is formed on the insulating layer 250 using a silicon-based inorganic film such as SiNx.

When the light generated from the organic light emitting layer 290 to be described later passes through the color SiO ₂ layer to be described later according to the viewing angle, the light compensation layer 300 has a color shift due to different transmittance of the color SiO ₂ layer for each subpixel. Shift) is to prevent the occurrence, it is preferable that the transmittance is 50% to 100% so that the light generated in the organic light emitting layer 290 is emitted through the substrate 200.

3C, the color SiO ₂ layer 260 is formed on the light compensation layer 300 by using a sputtering device. Specifically, when argon (Ar), nitrogen (N ₂ ), oxygen (O ₂ ) gas is injected into the chamber in a high vacuum state and gas is accelerated using an electric field, gas ions collide with the metal target to Comes out At the same time, the oxygen (O ₂ ) gas and Si in the light compensation layer react to form SiO ₂ , the metal particles separated from the metal target and SiO ₂ are mixed to form a colored SiO ₂ layer 260 on the light compensation layer 300. ) Is formed.

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

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

As shown in FIG. 3F, a solution process such as ink jet, nozzle coating, spray coating, roll printing, etc., is formed on the front surface of the bank 280 including the bank hole. The organic light emitting layer 290 including a plurality of organic layers is formed by the method. 3G, the second electrode 270b is formed on the organic emission layer 290.

Accordingly, holes and electrons injected into the organic light emitting layer 290 recombine to form an exciton, and the exciton falls to the ground state to emit light, and passes through the color SiO ₂ layer 260 under the organic light emitting display cell. Light corresponding to the color SiO ₂ layer 260 formed in each sub pixel is emitted.

In general, since the color filter is formed of an organic material, moisture adsorbed to the color filter may flow into the organic light emitting display cell, thereby reducing the reliability, lifespan, etc. of the organic light emitting display cell. However, the present invention provides a color SiO ₂ layer by a sputtering method. The stability of the organic light emitting display cell may be formed by forming the unit 260, and at the same time, the process may be simplified.

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

4A is a graph comparing the transmittances of the red SiO ₂ layer and the red color filter, FIG. 4B is a graph comparing the transmittances of the green SiO ₂ layer and the green color filter, and FIG. 4C is the transmittance of the blue SiO ₂ layer and the blue color filter. This is a graph comparing.

As shown in Figs. 4A, 4B and 4C, the difference in transmittance between the color filter and the color SiO ₂ layer is not large. That is, in the case of forming a color filter with an organic material, a general organic light emitting diode display in which a color filter is formed must further form a planarization layer to cover the color filter, and the gas generated in the process of forming the color filter and the planarization layer is organic. Inflow into the light emitting layer causes a problem of deteriorating the lifespan and reliability of the organic light emitting display cell.

However, the organic light emitting diode display of the present invention can prevent the above-described problems and at the same time ensure the same transmittance as the organic light emitting diode display having the color filter.

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: light compensation layer

Claims (17)

Board;
Each of the red, green, and blue subpixels may include a thin film transistor formed on the substrate;
An insulating film formed on the entire surface of the substrate including the thin film transistor;
A light compensation layer formed on the insulating film;
A color SiO ₂ layer formed on the light compensation layer;
A drain contact hole exposing the thin film transistor by selectively removing the insulating layer, the light compensation layer, and the color SiO ₂ layer; And
And an organic light emitting display cell formed on the color SiO ₂ layer and connected to the thin film transistor through the drain contact hole and including a first electrode, a plurality of organic layers, and a second electrode, which are sequentially stacked. Organic light emitting display device. The method of claim 1,
And the plurality of organic layers emit white light. The method of claim 1,
The color SiO ₂ layer comprises SiO ₂ and a metal or a metal compound. The method of claim 1,
The thickness of the color SiO ₂ layer is 0.1 ㎛ to 10 ㎛ organic light emitting display device. The method of claim 3, wherein
And the metal corresponding to the red subpixel is selenium (Se) or cadmium (Cd). The method of claim 3, wherein
And the metal corresponding to the green subpixel is cobalt oxide (CoO). The method of claim 3, wherein
And the metal corresponding to the blue subpixel is copper (Cu) or cobalt (Co). The method of claim 1,
And the light compensation layer is formed of SiNx. Forming a thin film transistor on each of the red, green, and blue subpixels on the substrate;
Forming an insulating film to cover the thin film transistor;
Forming a light compensation layer of SiNx on the insulating film;
Forming a colored SiO ₂ layer on the light compensation layer;
Selectively removing the insulating layer, the light compensation layer, and the color SiO ₂ layer to form a drain contact hole exposing the thin film transistor; And
Forming an organic light emitting display cell on the color SiO ₂ layer to be connected to the thin film transistor through the drain contact hole. The method of claim 9,
The forming of the organic light emitting 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,
The plurality of organic layers may emit white light. The method of claim 9,
And forming the color SiO ₂ layer using a sputtering method. 13. The method of claim 12,
The sputtering method uses a metal target, argon (Ar), nitrogen (N ₂ ) and oxygen (O ₂ ) gas. The method of claim 13,
In the sputtering method, the oxygen (O ₂ ) gas reacts with Si of the light compensation layer to form SiO ₂ , and at the same time, metal particles of the metal target are mixed with SiO ₂ to form a colored SiO ₂ layer on the light compensation layer. A method of manufacturing an organic light emitting display device, characterized in that the formation. The method of claim 13,
The metal target used in the formation of the color SiO ₂ layer of the red sub-pixel is selenium (Se) or cadmium (Cd) manufacturing method of an organic light emitting display device. The method of claim 13,
The metal target used in forming the color SiO ₂ layer of the green subpixel is cobalt oxide (CoO). The method of claim 13,
The metal target used in forming the color SiO ₂ layer of the blue sub-pixel is copper (Cu) or cobalt (Co) manufacturing method of an organic light emitting display device.

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