KR101560233B1 - Organic Light Emitting Display Device and Method for fabricating the same - Google Patents

Abstract

The present invention relates to an organic electroluminescent display device capable of improving lifetime and reducing power consumption and a method of manufacturing the same, wherein the organic electroluminescent display device is formed in a pixel portion defined by a vertical intersection of a gate line and a data line formed on a substrate An organic electroluminescent device formed on the transistor, an antireflective film formed between the substrate and the signal wiring including the gate line, the data line, and the power source line, and a substrate opposite to the one surface of the substrate on which the transistor is formed And a polarizing film formed on the other surface, wherein the anti-reflection film is formed of the same material as the semiconductor layer constituting the transistor.

OLED, external light, reflection, semiconductor layer, efficiency

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting display device,

The present invention relates to an organic light emitting display and a method of manufacturing the same, and more particularly, to an organic light emitting display capable of improving the lifetime and power consumption of an organic light emitting display and a method of manufacturing the same.

The image display device that realizes various information on the screen is a core technology of the information communication age and it is becoming thinner, lighter, more portable and higher performance. In recent years, along with the development of an information society, various types of display apparatuses have been increasingly demanded, and various kinds of displays such as a liquid crystal display (LCD), a plasma display panel (PDP), an electro luminescent display (ELD) Research on devices is actively under way. Among them, an organic light emitting display device for displaying an image by controlling the amount of emitted light of an organic light emitting layer by a flat panel display device which can reduce weight and volume, which is a disadvantage of a cathode ray tube (CRT)

The organic electroluminescence display device is a self-luminous device using a thin light emitting layer between electrodes, and has an advantage that it can be made thin like paper. In the active matrix organic electroluminescence display (AMOLED), pixels composed of three color (R, G, B) sub-pixels are arranged in a matrix form to display an image. Each sub-pixel is defined by the intersection of a gate line and a data line, and includes an organic electroluminescent device and a cell driver for independently driving the organic electroluminescent device. The cell driver includes at least two thin film transistors and a storage capacitor and controls the amount of current supplied to the organic light emitting display according to the data signal to control the brightness of the organic light emitting display.

Since the gate line, the data line, and the various signal lines for driving the organic light emitting display device are made of metal, the reflected light generated due to the reflection of the metal wires by the external light is mixed with the original output color, It falls very far. As a result, the light efficiency of the organic light emitting display device is lowered, and the lifetime is shortened and the power consumption is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an organic light emitting display device and a method of manufacturing the same that can improve lifetime and power consumption of an organic light emitting display device.

An organic light emitting display device according to the present invention includes a transistor formed in a pixel portion defined by a vertical intersection of a gate line and a data line formed on a substrate, an organic electroluminescent device formed on the transistor, An antireflection film formed between the substrate and a signal line including a power supply line, and a polarizing film formed on the other side of the substrate opposite to the one surface of the substrate on which the transistor is formed, wherein the antireflection film is the same as the semiconductor layer constituting the transistor Lt; / RTI >

Here, the semiconductor layer is formed of polycrystalline silicon or amorphous silicon.

The antireflection film is formed on the same layer as the semiconductor layer to have the same thickness.

The antireflection film overlaps with the signal wiring, and the width of the antireflection film is wider than the width of the signal wiring.

Here, the antireflection film is formed by extending 0.5 占 퐉 from both ends of the signal wiring formed on the antireflection film.

Meanwhile, the organic electroluminescent device emits light toward the substrate.

A method of manufacturing an organic light emitting display according to the present invention includes the steps of preparing a substrate defined by a pixel portion, a gate line portion, a data line portion, and a power line portion; forming a semiconductor layer on the substrate of the pixel portion, Forming an anti-reflection film on the substrate of the gate line portion, the data line portion, and the power source line portion; forming a gate electrode on the semiconductor layer of the pixel portion with the gate insulating film therebetween; Forming a gate electrode on the antireflection film; forming a source electrode and a drain electrode on the gate electrode side of the pixel portion with the interlayer insulating film therebetween to form a transistor; and forming, on the antireflection film of the data line portion, A power supply line is formed on the radiation prevention film of the power supply line portion And a generation step, and a step and forming the polarizing film on the other surface of the substrate wherein the substrate surface opposite to the - surface of the organic light emitting element formed to form an organic electroluminescent device in the transistor to the top.

Here, the organic electroluminescent device includes a first electrode formed on the transistor and connected to the transistor, and a second electrode formed on the first electrode with an organic light emitting layer therebetween, ITO, TO, IZO, ITZO or a combination thereof, and the second electrode is formed of Cr, Al, AlNd, Mo, Cu, W, Au, Ni, Ag or an alloy or oxide thereof.

According to the present invention, since a reflection preventing film is provided between various signal wirings such as a gate line and a data line and a substrate, reflection of various signal wirings due to external light can be prevented, and external visibility can be improved.

In addition, the light efficiency can be improved by improving the lifetime of the organic light emitting display device and reducing power consumption.

Furthermore, by forming the antireflection film by using the semiconductor layer used for the transistor, it is not necessary to additionally form the antireflection film formation step, thereby reducing the processing cost and time.

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.

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

The organic light emitting display according to the present invention includes a gate line 124b driven by a signal of a power supply line 128b formed on a substrate 110 defined by a pixel portion, a gate line portion, a data line portion, And is defined as a vertical intersection of line 128a.

A sub-pixel driver and an organic electroluminescent device are formed on the substrate 110 of the pixel portion. The sub-pixel driver mainly includes a switching transistor (not shown), a driving transistor, and a storage capacitor.

The switching transistor supplies the data signal from the data line 128a in response to the scan signal of the gate line 124b and the driving transistor outputs the amount of current flowing through the organic electroluminescent element in response to the data signal from the switching transistor . The storage capacitor serves to allow a constant current to flow through the driving transistor even if the switching transistor is turned off.

The driving transistor includes a semiconductor layer 122 formed on the buffer layer 112 of the pixel portion substrate 110 and a gate electrode 124a formed so as to overlap the channel portion of the semiconductor layer 122 with the gate insulating film 114 therebetween ). The driving transistor is connected to the source region and the drain region where the impurity ions are implanted in the semiconductor layer 122 on both sides of the gate electrode 124a through the contact hole formed in the interlayer insulating film 116 and the gate insulating film 114, And a source electrode 126 and a drain electrode 127 which are connected to each other.

The driving transistor described above is electrically connected to the first electrode 132 through the contact hole formed in the planarization film 118 to apply an electric field to the organic electroluminescent device.

The organic electroluminescent device emits red, green, and blue light in accordance with the current flow to display predetermined image information. The organic electroluminescent device includes a first electrode 132, a second electrode 136 as a counter electrode, And an organic light emitting layer 134 which is disposed and emits light. The first electrode 132 and the second electrode 136 are insulated from each other and a voltage having a different polarity is applied to the organic light emitting layer 134 to emit light.

The first electrode 132 is an anode electrode and is formed on the planarization layer 118 so as to be electrically connected to the drain electrode 127 of the driving transistor through a contact hole formed in the planarization layer 118. At this time, the first electrode 132 is formed as a transparent conductive layer so that light emitted from the organic light emitting layer 134 can be emitted toward the substrate 110 out of the device. As the transparent conductive layer, indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO) . The first electrode 132 is formed so as not to be connected to the first electrode 132 of the adjacent sub-pixel by a predetermined distance from the boundary of the sub-pixel.

The organic light emitting layer 134 is a layer in which the exciton formed by the combination of the holes and electrons injected from the first electrode 132 and the second electrode 136 falls to a ground state and emits light. The organic light emitting layer 134 may include a hole injection layer (HIL), a hole transporting layer (HTL), a light emitting layer (EL), an electron transporting layer (ETL) electron injection layer (EIL). At this time, the organic light emitting layer 134 is formed on the first electrode 132 so as to be divided into sub-pixel units by the bank insulating layer 138.

The second electrode 136 is a cathode electrode, and is formed over the entire surface of the substrate 110 in the form of a plate. The first electrode 132 may be formed of Cr, Al, AlNd, Mo, Cu, W, Au, Ni, or Ag, or may be formed of an alloy or oxide thereof. The organic electroluminescent device thus formed can emit red, green, and blue light in the direction of the substrate 110 in units of sub-pixels to display an image.

The gate line portion is a region in which a gate line 124b for applying a scan signal to the switching transistor is formed. On the substrate 110 in the gate line portion, a buffer layer 112, an antireflection film 172, a gate insulating film 114, A gate line 124b, an interlayer insulating film 116, and a planarization film 118 are sequentially stacked. At this time, the same names of the pixel portion and the gate line portion are made of the same material, and the gate line 124b is made of the same metal material as the gate electrode.

The data line portion is a region in which a data line 128b for supplying a data signal in response to a scan signal of the gate line 124b is formed. A buffer layer 112 and an anti-reflection film 172 are formed on the substrate 110 of the data line portion, A gate insulating film 114, an interlayer insulating film 116, a data line 128a, and a planarization film 118 are sequentially stacked. In this case, the same names of the pixel portion and the data line portion are made of the same material, and the data line 128a is made of the same metal material as the source and drain electrodes 126 and 127.

The power supply unit is a region where a power supply line 128b for applying a driving signal to the gate line 124b and the data line 128a is formed. The buffer layer 112, the anti-reflection film 172, A gate insulating film 114, an interlayer insulating film 116, a power supply line 128b, and a planarization film 118 are sequentially laminated. In this case, the same names of the pixel portion and the power source line portion are made of the same material, and the power source line 128b is made of the same metal material as the source and drain electrodes 126 and 127.

The antireflection film 172 formed on the gate line portion, the data line portion, and the power line portion is formed by a signal wiring made of a metal material such as a gate line 124b, a data line 128a, and a power source line 128b made of metal. Thereby blocking the reflection. The anti-reflection film 172 is formed between the gate line 124b, the data line 128a, and the power source line 128b and the substrate 110, which are signal lines.

At this time, the anti-reflection film 172 overlaps the signal wiring such as the gate line 124b, the data line 128a, and the power source line 128b and extends from both ends of the signal wiring. Specifically, the width of the antireflection film 172 is 0.5 占 퐉 each extending from both ends of various signal lines such as the gate line 124b, the data line 128a, and the power source line 128b formed on the antireflection film 172 Respectively. The width of the antireflection film 172 is designed to be wider than the width of the signal wiring such as the gate line 124b, the data line 128a, and the power source line 128b so that external light incident on the side surface of the signal wiring, It is possible to completely block it.

The antireflection film 172 is formed of the same material with the same thickness in the same layer as the semiconductor layer 122 of the driving transistor of the pixel portion. Examples include amorphous silicon or polycrystalline silicon, or amorphous silicon and polycrystalline silicon doped with ions.

In general, the transmittance of the semiconductor layer is about 30% in the visible light region as shown in the graph of FIG. 2A, and the reflectance of the semiconductor layer is less than 50% in the visible light region as shown in the graph of FIG. When such a semiconductor layer is formed between the signal wiring such as the gate line 124b, the data line 128a, and the power source line 128b and the substrate 110, only a part of the external light is transmitted to the signal wiring, And transmits a part of the partially reflected light. That is, the external light can be blocked in two or three steps to improve the external visibility. In addition, it is possible to improve the light efficiency of the organic electroluminescence display device, to improve the lifetime and to reduce the power consumption.

On the other side of the substrate 110 opposite to the one surface of the substrate 110 on which the anti-reflection film 172 is formed, a polarizing film 150 for preventing reflection of the organic light emitting display device is formed. The polarizing film 150 may be formed by coating a polarizing material on the substrate 110, or by attaching a polarizing material having flexibility to the substrate 110. The polarizing film 150 also prevents the surface of the substrate 110 from being damaged by external impact or scratch.

As described above, according to the present invention, the external light is firstly blocked by the polarizing film 150, the incident external light is blocked by the anti-reflection film 172 in the secondary and tertiary directions, The external light can be shut off completely.

Hereinafter, a method of manufacturing the organic light emitting display device shown in FIG. 1 will be described with reference to FIGS. 3A to 3I.

3A, a method of manufacturing an organic light emitting display according to an exemplary embodiment of the present invention includes preparing a substrate 110 defined as a pixel portion, a gate line portion, a data line portion, and a power line portion, The buffer layer 112 is formed on the entire surface.

Referring to FIG. 3B, an amorphous silicon or polycrystalline silicon layer is formed on the entire surface of the substrate 110. Thereafter, a semiconductor layer 122 is formed on the substrate 110 of the pixel portion by patterning amorphous silicon or polycrystalline silicon into an island shape by photo and etching processes, and at the same time, the substrate 110 of the gate line portion, the data line portion, The antireflection film 172 is formed.

Since the antireflection film 172 of the gate line portion, the data line portion, and the power line portion is formed by the same process with the same thickness and the same material in the same layer as the semiconductor layer 122 of the driving transistor of the pixel portion, It is possible to reduce the process cost and time.

Referring to FIG. 3C, the gate insulating layer 114 and the first metal layer are sequentially stacked over the entire surface of the substrate 110 including the semiconductor layer 122 and the anti-reflection layer 172. Then, the first metal film is patterned by photolithography and etching to form a gate electrode 124a at a position overlapping with the central portion of the semiconductor layer 122 of the pixel portion, and at the same time, The gate lines 124b are formed at positions overlapping with each other.

The width of the gate line 124b may be greater than the width of the antireflection film 172 of the gate line portion 124b so that the end of the antireflection film 172 is extended by the distance D1 from the end of the gate line 124b . Preferably, the width of the antireflection film 172 is formed to extend 0.5 占 퐉 at both ends of the gate line 124b. The width of the antireflection film 172 is made wider than the width of the gate line 124b so that the external light incident on the side surface of the gate line 124b can be blocked by the antireflection film 172. [

Referring to FIG. 3D, a source region 123a and a drain region 123b in which impurity ions are implanted into the semiconductor layer 122 using the gate electrode 124a as a mask, and a channel region 123c ). At this time, impurity ions may be implanted into the anti-reflection film 172 of the gate line portion, or may not be implanted.

Next, an interlayer insulating film 116 is formed on the substrate 110 on which the gate electrode 124a and the gate line 124b are formed.

Referring to FIG. 3E, a second metal film is formed on the interlayer insulating film 116, and the first metal film is patterned by photoetching and etching to pass through the interlayer insulating film 116 and the gate insulating film 114, A source electrode 126 and a drain electrode 127 connected to the drain region 123a and the drain region 123b, respectively. At the same time, a data line 128a is formed on the interlayer insulating film 116 in the data line portion, and a power source line 128b is formed on the interlayer insulating film 116 in the power line portion.

The end of the antireflection film 172 of the data line part is extended by the distance D2 from the end of the data line 128a and the end of the antireflection film 172 of the power line part is connected to the end of the power line 128b So as to be extended by a distance. That is, the width of the data line 128a is formed to be narrower than the width of the antireflection film 172 of the data line portion, and the width of the power source line 128b is formed to be narrower than the width of the antireflection film 172 of the power line portion. Preferably, the width of the antireflection film 172 is formed to extend 0.5 占 퐉 at both ends of the data line 128a and the power source line 128b. The width of the antireflection film 172 is wider than the width of the data line 128a or the power source line 128b so that the external light incident on the side of the data line 128a or the power source line 128b is reflected by the anti- .

Referring to FIG. 3F, a planarization layer 118 having a contact hole 119 exposing the drain electrode 127 is formed on the substrate 110.

Referring to FIG. 3G, after the transparent conductive layer is deposited, the transparent conductive layer is patterned by a photolithography process and an etching process using a mask to form a first electrode (not shown) connected to the drain electrode 127 exposed through the contact hole 119, (132) is formed on the planarizing film (118) of the pixel portion. (ITO), a tin oxide (TO), an indium zinc oxide (IZO), an indium tin zinc oxide (ITZO), or a transparent conductive layer of indium tin oxide Combinations are used.

Next, a bank insulating layer 138 is formed on the whole surface of the substrate 110 on which the first electrode 132 is formed, and then an insulating material is applied to the entire surface of the substrate 110 to selectively remove the organic light emitting devices. At this time, the bank insulating layer 138 is formed on the planarization film 118 on the driving transistor of the gate line portion, the data line portion, the power supply line portion, and the pixel portion.

Referring to FIG. 3H, an organic light emitting layer 134 is formed on the first electrode 132 exposed by the bank insulating layer 138 by depositing an organic material through a vapor deposition method such as thermal evaporation. The organic light emitting layer 133 may include a hole injection layer (HIL), a hole transporting layer (HTL), a light emitting layer (EL), an electron transporting layer (ETL) electron injection layer (EIL). Here, the organic light emitting layer 134 is divided into sub-pixel units by the bank insulating layer 138, and is formed to emit red, green, and blue light in units of sub-pixels.

A conductive material is deposited on the entire surface of the substrate 110 on which the organic light emitting layer 134 is formed to form the second electrode 136. The second electrode 136 may be formed by a deposition method such as sputtering such as Cr, Al, AlNd, Mo, Cu, W, Au, Ni, or Ag. or may be formed of a multilayer.

Referring to FIG. 3I, a passivation layer 130 is formed on the substrate 110 on which the second electrode 136 is formed, and the encapsulation process is performed. At this time, an encapsulating substrate or the like may be used in place of the protective film 130.

Next, a polarizing film 150 is formed on the other surface of the substrate 110, which is a surface opposite to one surface of the substrate 110 on which the organic electroluminescent device is formed. The polarizing film 150 prevents reflection of the organic light emitting display device and prevents the surface of the substrate 110 from being damaged by external impact or scratch. The polarizing film 150 may be formed by coating a polarizing material on the substrate 110, or by attaching a polarizing material having flexibility to the substrate 110.

In the organic light emitting display according to the present invention thus formed, light is emitted toward the substrate 110, so that a screen is displayed on the substrate 110. At this time, external light is firstly blocked by the polarizing film 150, and the incident external light is blocked by the antireflection film 172 in the secondary and tertiary directions, and the slightly reflected external light is reflected by the polarizing film 150 By blocking the fourth order, external light can be completely cut off. In addition, by improving the visibility of the external light, the light efficiency and lifetime of the organic light emitting display device can be improved and the power consumption can be reduced.

The above-described techniques represent presently preferred embodiments, and the present invention is not limited to the above-described embodiments and the accompanying drawings. Modifications and other uses of the embodiments will be apparent to those skilled in the art, and such modifications and other uses are intended to be included within the spirit of the present invention or defined by the scope of the appended claims.

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

2A and 2B are graphs showing transmittance and reflectance of the semiconductor layer.

3A to 3I are cross-sectional views illustrating a method of manufacturing the organic light emitting display shown in FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

110: substrate 112: buffer layer

114: gate insulating film 118: planarization film

122: semiconductor layer 124a: gate electrode

124b: gate line 126: source electrode

127: drain electrode 128a: data line

128b: power supply line 132: first electrode

134: organic light emitting layer 136: second electrode

138: bank insulating layer 150: polarizing film

172: antireflection film

Claims (10)

A transistor provided in a pixel portion defined as a vertical intersection of a gate line and a data line located on a transparent substrate; An organic electroluminescent device on the transistor; An antireflection film positioned between the signal lines including the gate line, the data line, and the power source line and the substrate so as to correspond to the signal lines; And And a polarizing film disposed on the other surface of the substrate opposite to one surface of the substrate provided with the transistor, Wherein the antireflection film is formed of the same material as the semiconductor layer constituting the transistor. The organic electroluminescent display device according to claim 1, wherein the semiconductor layer is polycrystalline silicon or amorphous silicon. The organic light emitting display according to claim 2, wherein the antireflection film is located on the same layer as the semiconductor layer with the same thickness. The organic electroluminescent display device according to claim 1, wherein the antireflection film overlaps with the signal wiring, and the width of the antireflection film is larger than the width of the signal wiring. 5. The organic light emitting display according to claim 4, wherein the anti-reflection film extends 0.5 占 퐉 from both ends of the signal wiring located above the anti-reflection film. The organic light emitting display according to claim 1, wherein the organic electroluminescent device emits light toward the substrate. Preparing a substrate defined by a pixel portion, a gate line portion, a data line portion, and a power source line portion; Forming a semiconductor layer on the substrate of the pixel portion and forming an anti-reflection film on the substrate at a position corresponding to the gate line portion, the data line portion, and the power source line portion; Forming a gate insulating film on the entire surface of the substrate including the semiconductor layer and the antireflection film, forming a gate electrode at a position corresponding to the central portion of the semiconductor layer of the pixel portion on the gate insulating film, Forming a gate line at a position overlapping with a center portion of the gate line; Forming a source electrode and a drain electrode on the gate electrode side portion of the pixel portion with an interlayer insulating film interposed therebetween to form a transistor and forming a data line at a position corresponding to the antireflection film of the data line portion, Forming a power supply line at a position corresponding to the antireflection film; Forming an organic electroluminescent device on the transistor; And And forming a polarizing film on the other surface of the substrate opposite to one surface of the substrate on which the organic electroluminescent device is formed. The method as claimed in claim 7, wherein the antireflection film overlaps the gate line, the data line, and the power source line, and the width of the antireflection film is wider than the width of the gate line, the data line, A method of manufacturing an organic electroluminescent display device. The method according to claim 8, wherein the anti-reflection film is formed by extending 0.5 占 퐉 at both ends of the gate line, the data line, and the power source line. The organic electroluminescent device of claim 7, wherein the organic electroluminescent device comprises a first electrode formed on the transistor and connected to the transistor, and a second electrode formed on the first electrode with an organic light emitting layer therebetween, Wherein the first electrode is formed of ITO, TO, IZO, ITZO, or a combination thereof, Wherein the second electrode is formed of Cr, Al, AlNd, Mo, Cu, W, Au, Ni, Ag, or an alloy or oxide thereof.

Images