KR100822959B1 - Organic Electroluminescence Display of having Reflective Side Wall and Method of manufacturing the same - Google Patents

Abstract

An organic electroluminescent device having a reflective sidewall for reflecting light generated from a light emitting layer and a method of manufacturing the same are disclosed. Light generated from the organic film formed in the spaced space between the reflective sidewalls is reflected by the reflective sidewall and is emitted to the outside of the substrate. In addition, the reflective sidewall is formed in an area where the substrate is exposed between the anode electrode patterns. Therefore, the light generated in the organic film can be easily emitted to the outside of the substrate without disappearing inside.

Description

Organic electroluminescence display having reflective sidewalls and a method of manufacturing the same.

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

2A to 2D are perspective views and cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to a preferred embodiment of the present invention.

3 is a cross-sectional view showing another organic electroluminescent device having reflective sidewalls in accordance with a preferred embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100, 200: substrate 115, 215: anode electrode pattern

130 and 230: reflective sidewalls 131 and 231: first insulating layer

133 and 233: reflective layer 135 and 235: second insulating layer

160, 260: organic film 170, 270: cathode electrode

The present invention relates to an organic electroluminescent device, and more particularly to an organic electroluminescent device having a reflective layer around the light emitting region.

The organic electroluminescent device performs a light emitting operation with a predetermined luminance according to a driving current corresponding to a voltage applied between an anode electrode and a cathode as a self-luminous element. The organic light emitting device is classified into an active matrix type and a passive matrix type according to a method of driving an emitter made of organic material.

The active matrix type has an active element for controlling the driving current according to the scan signal and the data signal for each of the plurality of pixels arranged in the matrix form. In particular, each pixel includes at least two thin film transistors to compensate for variations in the applied data signal or to form a more accurate driving current, and generates a driving current by the operation of the provided thin film transistors. The generated driving current is applied to the organic light emitting diode, and the organic light emitting diode emits light with a predetermined brightness.

In the passive matrix type, a plurality of pixels are arranged in a matrix form. Each pixel has an organic light emitting diode, an anode electrode and a cathode electrode composed of organic light emitting bodies. The anode electrode and the cathode electrode vertically cross each other, and the organic light emitting body is interposed in the vertically crossing area. The emission principle of the passive matrix type organic light emitting display device is to apply a predetermined voltage to each of the anode electrode and the cathode electrode, and apply a forward bias to the organic light emitting element that serves as a diode to emit light at a predetermined brightness.

In addition, according to the direction in which light is emitted regardless of the passive matrix and the active matrix, the organic light emitting device is classified into a top emission type and a bottom emission type.

In the top emission type, light is emitted in a direction opposite to the substrate on which the organic light emitting body is formed. That is, when the substrate, the anode electrode, the organic light emitting body and the cathode electrode are arranged, light is emitted from the organic light emitting body through the cathode electrode. Thus, a reflecting plate is provided below the anode electrode or above the substrate.

In the case of the bottom emission type, light is emitted from the organic light emitting body toward the substrate. In general, the anode electrode is made of transparent indium tin oxide (ITO), and the cathode electrode is made of Al, Mg-Au, Li, or Ca, which is metallic and has high light reflectivity. Therefore, the light generated from the organic light emitting body passes through the substrate through the anode electrode, or is reflected from the cathode electrode and passes through the substrate to be emitted to the outside.

Each of the two light emitting forms described above has advantages and disadvantages.

First, in the case of top emission, there is an advantage in that a plurality of thin film transistors can be easily formed between the emission layer and the anode electrode on which the organic emission layer is formed. However, in order for the top emitting structure to be formed, the cathode electrode must be transparent. In order to obtain a transparent cathode electrode, a method of forming a metal pattern into a thin film is used. When the cathode is made of a metal thin film, there is a disadvantage in that the resistance of the cathode is increased.

In addition, in the case of the bottom emission, the cathode is used for the light reflection, and thus the light emission operation can be easily performed without using a separate reflector. However, in the recent active type, since a plurality of active elements are provided between the light emitting layer and the anode electrode, there is a problem in that the aperture ratio due to the bottom emission is reduced.

In addition, there is a problem that the luminous efficiency is reduced due to the partition wall defining each pixel irrespective of the light emission form. The partition wall is made of an insulator, and has a structure for absorbing light incident from the outside. Therefore, a black system insulator is used as the partition wall. However, the black system insulator has a characteristic of absorbing not only the light incident from the outside but also the light emitted by the light emitting layer. Therefore, a problem arises that the luminous efficiency is lowered due to the black system insulator.

Therefore, there is a need for an organic electroluminescent device in which light generated in the organic electroluminescent device is prevented from being extinguished by internal reflection, and the generated light can be easily emitted to the outside.

A first object of the present invention for solving the above problems is to provide an organic electroluminescent device having a reflective side wall that can efficiently reflect the generated light to increase the light efficiency.

In addition, a second object of the present invention is to provide a method of manufacturing an organic light emitting device for achieving the first object.

The present invention for achieving the first object, a transparent material substrate; An anode electrode pattern formed on the substrate and made of a transparent material conductor; Reflective sidewalls formed on the spaced spaces between the anode electrode patterns; An organic layer formed on the anode electrode pattern; And a cathode electrode pattern formed on the organic layer, and the reflective sidewalls reflect light generated from the organic layer.

In addition, the first object of the present invention, a transparent material substrate; An anode electrode pattern formed on the substrate and made of a transparent material conductor; Reflective sidewalls formed in an area where the substrate is exposed between the anode electrode patterns adjacent to each other; A transparent insulating film pattern formed on the reflective sidewall; Barrier ribs formed on the insulating layer pattern to define pixels; An organic layer formed on the anode electrode pattern; And a cathode electrode formed on the organic layer, and the reflective sidewall may be achieved through the provision of an organic light emitting device, characterized in that for reflecting light generated from the organic layer.

In addition, the present invention for achieving the second object, forming an anode electrode pattern on a substrate; Forming reflective sidewalls in the spaced spaces between the anode electrode patterns; Forming an organic layer on the anode electrode pattern; And forming a cathode electrode pattern on the organic layer, wherein the reflective sidewall reflects light generated from the organic layer.

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

Example

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

Referring to FIG. 1, the organic light emitting display device according to the present embodiment includes a substrate 100, an anode electrode pattern 115 formed on the substrate 100, and an organic layer 160 formed on the anode electrode pattern 115. ) And a reflective sidewall 130 formed between the cathode electrode 170 formed on the organic layer 160 and the anode electrode patterns 115.

The substrate 100 is composed of a member of a transparent material. In addition, an anti-reflection film or a polarizing plate for blocking the incidence of light from the outside may be further provided as a separate member under the substrate 100.

The anode electrode pattern 115 is formed on the substrate 100. In addition, the anode electrode pattern 115 is made of indium-tin-oxide (ITO) or indium zinc oxide (IZO) film, which is a transparent conductive material. The selection of the anode electrode material is made by selecting a metal having a high work function. In addition, the anode electrode is formed through deposition on the entire surface of the substrate (100). In addition, it is preferable to form the deposited anode electrode in a stripe pattern.

Reflecting sidewalls 130 are formed on the separation space between the anode electrode patterns 115 and the substrate 100. The reflective sidewall 130 may reflect light generated from the organic layer 160 and have a property of insulating an electrically adjacent pixel. Accordingly, the reflective sidewall 130 is composed of a first insulating layer 131, a reflective layer 133, and a second insulating layer 135. In addition, the first insulating layer 131 may be made of any material having an electrically insulating property, and the second insulating layer 135 may be made of a transparent insulating material. The reflective layer 133 may be any material that can reflect light generated from the organic layer 160. Preferably, the reflective layer 133 is made of Al, Al-Nd, Ag, Ag alloy, Cr or Cr alloy.

An organic layer 160 is formed on side surfaces of the reflective sidewall 130 and on the anode electrode pattern 115. The organic layer 160 is made of an organic material and includes an organic light emitting layer. Holes generated in the anode electrode pattern 115 and electrons generated in the cathode electrode 170 are combined in the organic emission layer to perform light emission with a predetermined brightness. In addition, the organic layer 160 may further include a hole injection layer, a hole transport layer, an electron transport layer and an electron transport layer.

The cathode electrode pattern 170 is formed on the organic layer 160. The cathode electrode pattern 170 is made of a conductive material and is made of a material capable of reflecting light. Accordingly, the cathode electrode pattern 170 is made of Al, Mg-Au, Li, or Ca having a high light reflectance. In addition, the cathode electrode pattern 170 is preferably disposed perpendicular to the direction in which the anode electrode pattern 115 is disposed. Accordingly, the organic layer 160 is formed in the region where the cathode electrode pattern 170 and the anode electrode pattern 115 intersect, and is applied to a voltage or current applied between the anode electrode pattern 115 and the cathode electrode pattern 170. As a result, the organic layer 160 performs light emission at a predetermined luminance.

Thus, reflective sidewalls 130 are provided on the sidewalls of the organic layer 160 and the space between the anode electrode patterns 115. The reflective sidewall 130 may have a shape surrounding the outer side of the organic layer 160. The light generated by the organic layer 160 is reflected by the reflective layer 133 of the reflective sidewall 130, and the light reflected by the reflective layer 133 does not disappear from the inside, but passes through the substrate 100 to the outside. It is emitted.

In addition, an insulating layer pattern 140 and a partition wall 150 may be formed on the reflective sidewall 130. The insulating layer pattern 140 and the partition wall 150 are used to define respective pixels of red, green, and blue. Therefore, the reflective sidewall 130, the insulating layer pattern 140, and the partition wall 150 may be formed to surround each pixel.

In addition, the insulating layer pattern 140 is formed of an insulating material of a transparent material. In FIG. 1, the height of the reflective sidewall 130 is greater than the top surface of the cathode electrode pattern 170, but the height of the reflective sidewall 130 may be lower than the top surface of the cathode electrode pattern 170. In addition, electrical insulation between adjacent pixels may also be achieved by the reflective sidewall 130, the insulating layer pattern 140, and the partition wall 150.

2A to 2D are perspective views and cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to a preferred embodiment of the present invention.

In the present exemplary embodiment, the reflective sidewall is provided in the spaced space between adjacent anode electrode patterns and is formed on the substrate.

First, referring to FIG. 2A, an anode electrode 110 is formed on a transparent substrate 100. The anode electrode 110 is made of ITO or IZO, which is a transparent conductor.

Referring to FIG. 2B, a photoresist is coated on the surface of the substrate 100 on which the anode electrode 110 is formed, and the anode electrode pattern 115 is formed using a conventional photolithography process. Therefore, the substrate 100 of the transparent material is exposed in the space between the adjacent anode electrode patterns 115. Hereinafter, such an area is referred to as an exposed area 120.

Subsequently, reflective sidewalls are formed on the exposed region 120 where the substrate 100 is exposed between adjacent anode electrode patterns 115.

FIG. 2C is a cross-sectional view of the reflective sidewall formed in the exposed region 120 between the lower electrode patterns 115 illustrated in FIG. 2B in the AA ′ direction.

Referring to FIG. 2C, reflective sidewalls 130 are formed on the exposed region 120. First, the first insulating layer 131 is formed on the exposed area 120 where the substrate 100 is exposed. The first insulating layer 131 may be formed by chemical vapor deposition, physical vapor deposition, or coating. In addition, a photoresist is formed on an insulator formed on the entire surface of the substrate 100 and patterned to form a photoresist pattern. When the dry etching is performed using the formed photoresist pattern as a mask, the first insulating layer 131 may be formed. In addition to dry etching, wet etching may be performed to form the first insulating layer 131. The first insulating layer 131 may be any insulator having an etch ratio different from that of ITO or IZO forming the anode electrode pattern 115.

Subsequently, a reflective layer 133 is formed on the surface of the first insulating layer 131. The reflective layer 133 may be any material that can reflect light. Preferably, the reflective layer 133 is made of Al, Al-Nd, Ag, Ag alloy, Cr or Cr alloy. The formation of the reflective layer 133 is formed by chemical vapor deposition or physical vapor deposition. Preferably, a material forming the reflective layer 133 is applied to the surface of the first insulating layer 131 and the anode electrode pattern 115 through sputtering, which is a kind of physical vapor deposition. After the photoresist is applied on the applied reflective layer 133 and a pattern is formed through exposure, the reflective layer 133 is formed only on the surface of the first insulating layer 131 using an etching process.

In addition, although the material constituting the reflective layer 133 is illustrated as a metal in FIG. 2C, an organic material capable of reflecting light may be used as the reflective layer 133.

Subsequently, a second insulating layer 135 is formed on the surface of the reflective layer 133. The second insulating layer 135 may be used as long as it is a material capable of maintaining an electrical insulating property while maintaining optical transparency. In addition, the second insulating layer 135 is formed through chemical vapor deposition, physical vapor deposition or coating. Preferably, the second insulating layer 135 is formed through the coating. When a coating or deposition process is used, the second insulating layer 135 is applied to the entire surface of the reflective layer 133 and the anode electrode pattern 115. Therefore, only the second insulating layer 135 on the surface of the reflective layer 133 is left using a conventional photolithography process, and the second insulating layer 135 in the remaining area is removed.

In addition, the second insulating layer 135 is formed while filling a space between the reflective layer 133 and the anode electrode pattern 115.

Therefore, the reflective sidewall 230 is formed in the exposed region between the anode electrode patterns 115.

Referring to FIG. 2D, an insulating film pattern 140 and a partition wall 150 are formed on the insulating film pattern 140 on the substrate 100 on which the reflective sidewall 130 is formed. The insulating layer pattern 140 and the partition wall 150 are provided to define respective pixels of red, green, and blue. That is, it is formed while surrounding the pixel area to define the area where the pixel is formed. In addition, the insulating layer pattern 140 may be formed of the same material as the second insulating layer 135. Therefore, the insulating layer pattern 140 is not formed in a different manufacturing process from the second insulating layer 135, but may be made through the same manufacturing process. That is, when the second insulating layer is formed, the insulating film pattern on the upper side of the reflective sidewall is formed to be thick, so that the formation of the insulating film pattern according to a separate manufacturing process may be avoided.

Subsequently, the organic layer 160 and the cathode electrode 170 are sequentially formed on the anode electrode pattern 115 and on the side surfaces of the anode electrode and the reflective sidewall.

Light generated from the formed organic layer 160 is reflected by the reflective layer 133 provided on the reflective sidewall 130. In addition, the reflected light is not extinguished inside, but may be emitted to the outside through the substrate 100. Therefore, the luminous efficiency of the organic light emitting device is increased.

2A to 2D, after forming the reflective sidewall, the organic layer is formed, but the insulating layer pattern and the partition wall are sequentially formed on the reflective sidewall, and are defined by the reflective sidewall, the insulating layer pattern, and the partition wall. An organic film may be formed in the pixel region. Therefore, not only the reflective sidewall is formed to surround the pixel region, but the insulating layer pattern and the partition wall may be formed to surround the pixel region. In addition, the insulating film pattern is preferably composed of a transparent insulating material.

3 is a cross-sectional view showing another organic electroluminescent device having reflective sidewalls in accordance with a preferred embodiment of the present invention.

Referring to FIG. 3, the organic light emitting device has the same structure as the organic light emitting device shown in FIG. 1 except for the reflective sidewall 230.

That is, the organic electroluminescent device of FIG. 3 has a configuration of another reflective sidewall for maintaining electrical insulation with adjacent pixels. The first insulating layer 231 constituting the reflective sidewall 230 is formed in the spaced space between the anode electrode patterns 215 formed on the substrate 200. In addition, a reflective layer 233 is formed on the surface of the first insulating layer 231. The composition of the reflective layer 233 is the same as described with reference to FIG. However, one side of the reflective layer 233 is formed to be in contact with the anode electrode pattern 215, and the other side of the reflective layer 233 is electrically insulated from the anode electrode pattern 215 through the second insulating layer 235. Is formed.

As such, as one side of the reflective layer contacts the anode electrode pattern, the reflective layer may simultaneously serve as an auxiliary electrode of the anode electrode. That is, the voltage drop generated due to the limitation of the thickness of the anode electrode pattern may be minimized by electrically connecting the reflective layer with the anode electrode pann.

In addition, a second insulating layer 235 is formed on the surface of the reflective layer 233. One side of the second insulating layer 235 is formed while filling the space between the reflective layer 233 and the anode electrode pattern 215, and the other side of the second insulating layer 235 is the reflective layer 233 and the organic layer 260. It is formed while filling the space between them.

The structures of the insulating film pattern 240 and the partition wall 250 formed on the second insulating layer 235 are the same as those shown in FIG. 1.

In addition, the cathode electrode pattern 270 formed on the organic layer 260 is also the same as that described in FIG. 1, and thus descriptions thereof are omitted for easy understanding and avoiding overlapping substrates.

In the organic electroluminescent device of FIG. 3 described above, one side of the reflective layer 233 is formed from the anode electrode surface, and the other side of the reflective layer 233 is formed from the substrate surface. Light generated from the formed organic layer 260 is reflected by the reflective layer 233 provided on the reflective sidewall 230. In addition, the reflected light is not extinguished inside, but may be emitted to the outside through the substrate 200. Therefore, the luminous efficiency of the organic light emitting device is increased.

According to the present invention as described above, the light generated in the organic film is reflected by the reflective side wall. The reflected light is emitted to the outside of the substrate through a predetermined path. Therefore, the light efficiency of the organic light emitting device is increased. In addition, by allowing the reflective sidewall to serve as an auxiliary electrode of the anode, it is possible to minimize the voltage drop due to the resistance of the anode electrode pattern.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (12)

A substrate made of a transparent material; An anode electrode pattern formed on the substrate and made of a transparent material conductor; Reflective sidewalls formed on the spaced spaces between the anode electrode patterns; An organic layer formed on the anode electrode pattern; And A cathode electrode pattern formed on the organic layer, The reflective sidewalls reflect light generated from the organic layer, A first insulating layer formed on the spaced space between the anode electrode patterns, a side surface of the first insulating layer and an upper surface of the first insulating layer, and a reflective layer for reflecting light and a surface formed on the reflective layer; And a second insulating layer of a transparent material filling a space between the anode electrode pattern and the anode electrode pattern. delete The organic electroluminescent device according to claim 1, wherein the reflective layer is Al, Al-Nd, Ag, Ag alloy, Cr or Cr alloy. The display device of claim 1, wherein the organic light emitting diode further comprises an insulating film pattern and a partition wall defining a pixel area on the reflective sidewall, and the reflective side wall, the insulating film pattern and the partition wall are formed to surround the pixel area. Organic electroluminescent device, characterized in that. The organic light emitting device of claim 1, wherein the organic light emitting device further comprises an antireflection film or a polarizing plate for blocking light incident from the outside under the substrate. Forming an anode electrode pattern on the substrate; Forming a first insulating layer in the spaced space between the anode electrode patterns; Forming a reflective layer formed to cover the side surface and the upper surface of the first insulating layer and reflecting light; Forming a transparent second insulating layer on the reflective layer; Forming an organic layer on the anode electrode pattern; And Forming a cathode electrode pattern on the organic layer; The reflective layer is a method of manufacturing an organic light emitting display device, characterized in that for reflecting the light generated from the organic film. delete The method of claim 6, wherein the reflective layer is Al, Al-Nd, Ag, Ag alloy, Cr or Cr alloy. The method of claim 6, wherein the reflective layer is formed by sputtering. The method of claim 6, further comprising, after forming the second insulating layer, forming an insulating layer pattern and a partition wall to define a pixel. A substrate made of a transparent material; An anode electrode pattern formed on the substrate and made of a transparent material conductor; Reflective sidewalls formed in an area where the substrate is exposed between the anode electrode patterns adjacent to each other; A transparent insulating film pattern formed on the reflective sidewall; Barrier ribs formed on the insulating layer pattern to define pixels; An organic layer formed on the anode electrode pattern; And A cathode electrode formed on the organic layer, The reflective sidewall is formed to cover a first insulating layer formed in a spaced space between the anode electrode patterns adjacent to each other, a side surface and an upper surface of the first insulating layer, the reflective layer for reflecting light and the surface of the reflective layer A second insulating layer formed of a transparent material, And the second insulating layer is formed on a surface of the reflective layer such that one side of the reflective layer may contact one surface of the adjacent anode electrode. delete

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