KR20030057016A - organic electroluminescence display devices - Google Patents

Abstract

PURPOSE: An organic electroluminescence device is provided to reduce a badness and to improve a visibility by preventing a static electricity from being generated. CONSTITUTION: The first electrode(151) is formed at a lower surface of a transparent insulating substrate(110) as a hole supplying layer. An organic luminescence layer(160) is formed at a lower part of the first electrode. The second electrode(170) is formed at a lower part of the organic luminescence layer as an electron supplying layer. A circular polarization part(180) is disposed at an upper surface of the substrate. A transparent electrode(190) is formed on the circular polarization part.

Description

Organic electroluminescence display devices

The present invention relates to an organic electroluminescent device comprising an organic light emitting layer.

An electroluminescence display (or electroluminescence display (ELD)) is a display element using an electroluminescence (EL) phenomenon that generates light when a certain amount of electric field is applied to a phosphor, and is a source of excitation of carriers. According to the present invention, the organic light emitting device may be classified into an inorganic electroluminescent device and an organic electroluminescence display (OELD or organic ELD).

Among them, the organic electroluminescent device is attracting attention as a natural color display device because it emits light in all regions of visible light including blue, and has high luminance and low operating voltage characteristics. In addition, because of self-luminous, the contrast ratio is high, the ultra-thin display can be realized, and the process is simple, so that environmental pollution is relatively low. On the other hand, the response time is easy to implement a moving picture with a few microseconds, there is no restriction on the viewing angle, it is stable even at low temperatures, it is easy to manufacture and design a drive circuit because it is driven at a low voltage of DC 5V to 15V.

The organic electroluminescent device has a structure similar to that of an inorganic electroluminescent device, but the light emitting principle is called organic light emitting diode (OLED) because the light emission is achieved by recombination of electrons and holes. Therefore, hereinafter, referred to as organic LED.

Recently, an active matrix form in which a plurality of pixels are arranged in a matrix form and thin film transistors are connected to each pixel is widely used in flat panel displays, and an active matrix organic LED is applied to an organic electroluminescent device. LED: AMOLED) will be described with reference to the accompanying drawings.

1 is a cross-sectional view of a conventional active matrix organic LED. As illustrated, a thin film transistor T is formed on the substrate 10, and a protective layer 41 is formed thereon to cover the thin film transistor T. The thin film transistor T includes a gate electrode 21 and source and drain electrodes 22 and 23, and includes an active layer 31.

An anode electrode 51, which is made of a transparent conductive material and is a hole supply layer, is formed on the passivation layer 41, and the anode electrode 51 is a drain electrode 23 of the thin film transistor T. Connected with Subsequently, an organic emission layer 60 is formed on the anode electrode 51, and a cathode electrode 70 made of an opaque conductive material and an electron supply layer is formed thereon.

In the active matrix organic LED, since the lower anode electrode 51 is made of a transparent conductive material and the upper cathode electrode 70 is made of an opaque conductive material, the light emitted from the organic light emitting layer 60 is like an arrow. It is emitted downward through the anode electrode 51. Therefore, it is preferable that the board | substrate 10 consists of a transparent board | substrate, and in order to express an image, the board | substrate 10 of an organic LED is arrange | positioned upwards.

Recently, as illustrated in FIG. 2, an example in which a circular polarizer 80 is disposed on the other side of the substrate 10 of the active matrix organic LED is presented. The circular polarizer 80 may improve the contrast ratio of the organic LED, and may improve visibility, which is a degree in which colors are easily seen.

However, static electricity is generated during the process of attaching the circular polarizer 80 to the substrate 10 or by contact with the outside after the attachment. The static electricity generated at this time not only causes a defect of the organic LED, but also has a problem of decreasing visibility.

The present invention has been made to solve the above-mentioned conventional problems, an object of the present invention is to provide an organic electroluminescent device that can prevent the generation of static electricity to reduce defects and improve visibility.

1 is a cross-sectional view of a conventional organic electroluminescent device.

2 is a cross-sectional view of another conventional organic electroluminescent device.

3 is a cross-sectional view of an organic electroluminescent device according to a first embodiment of the present invention.

4 is a cross-sectional view of an integrated circular polarizer according to a first embodiment of the present invention.

5 is a cross-sectional view of an organic electroluminescent device according to a second embodiment of the present invention.

6 is a cross-sectional view of an integrated circular polarizer according to a second embodiment of the present invention.

7A to 7F illustrate the structure of a conductive polymer.

<Description of Symbols for Main Parts of Drawings>

110 substrate 121 gate electrode

122 source electrode 123 drain electrode

131: active layer 141: protective layer

151: anode electrode 160: organic light emitting layer

170: cathode layer 180: circular polarizer

190: transparent electrode T1: thin film transistor

In the organic electroluminescent device according to the present invention for achieving the above object, a first electrode, which is a hole supply layer, is formed on a lower surface of a transparent insulating substrate, and an organic light emitting layer is formed under the first electrode. Next, a second electrode, which is an electron supply layer, is formed below the organic emission layer. Next, a circular polarizer is arranged on the upper surface of the substrate, and a transparent electrode is formed thereon.

In another organic electroluminescent device according to the present invention, a first electrode serving as a hole supply layer is formed on a lower surface of a transparent insulating substrate, and an organic light emitting layer is formed under the first electrode. Next, a second electrode, which is an electron supply layer, is formed below the organic emission layer. Next, a transparent electrode is formed on the upper surface of the substrate, and a circular polarizer is disposed thereon.

Here, the circular polarizer and the transparent electrode may be integrally formed.

In addition, the transparent electrode may be made of indium tin oxide, wherein the transparent electrode may be formed by a coating method, or may be deposited by a sputtering method.

Meanwhile, the transparent electrode may be made of any one of poly (3,4-ethylenedioxythiophene), polyaniline, polyacetylene, poly paraphenylene, polypyrrole and polythiophene.

The present invention may further include a thin film transistor connected to the first electrode.

As described above, in the present invention, the circular polarizer is attached to one surface of the organic LED to increase the contrast ratio of the organic LED, thereby improving visibility, and by forming a transparent electrode on the upper or lower part of the circular polarizer and grounding, It can prevent and prevent the defect by static electricity.

Hereinafter, an organic LED according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, FIG. 3 is a cross-sectional view of an active matrix organic LED according to a first embodiment of the present invention. At this time, Figure 3 shows the light is arranged so that the portion comes to the top.

As illustrated, a plurality of thin film transistors T1 are formed under the transparent substrate 110, and the thin film transistors T1 are formed of the gate electrode 121, the source and drain electrodes 122 and 123, and are polycrystalline. It includes an active layer 131 made of silicon. Here, it is preferable that the board | substrate 110 consists of a transparent board | substrate like a glass substrate.

Next, a protective layer 141 having a contact hole exposing the drain electrode 123 of the thin film transistor T1 is formed under the thin film transistor T1, and an anode electrode 151 is formed under the protective layer 141. It is. The anode electrode 151 is connected to the drain electrode 123 and preferably formed of a transparent conductive material as a hole supply layer, and may be formed of a material such as indium-tin-oxide (hereinafter referred to as ITO). Can be done.

Subsequently, an organic emission layer 160 is formed under the anode electrode 151. Although the organic light emitting layer 160 is formed over the entire surface of the substrate, the organic light emitting layer 160 may be patterned to correspond one-to-one with the anode electrode 151.

Next, a cathode electrode 170 made of an opaque conductive material such as a metal is formed below the organic emission layer 160, and the cathode electrode 170 supplies electrons to the organic emission layer 160.

On the other hand, the circular polarizer 180 is formed on the substrate 110 to improve the contrast ratio of the organic LED to increase visibility, and the transparent electrode 190 is formed on the circular polarizer 180. The transparent electrode 190 may be made of a transparent conductive material such as ITO. The transparent electrode 190 may be formed by coating ITO in a gel form on the circular polarizer 180 on the substrate 110 or by sputtering. It may be formed by vapor deposition.

In addition, as shown in FIG. 4, the circular polarizer 180 and the transparent electrode 190 may be attached to the substrate 110 of FIG. 3.

The organic LED is mounted in the conductive case, and the transparent electrode 190 is connected to the case so that the transparent electrode 190 is grounded. Therefore, it is possible to prevent the generation of static electricity and thereby prevent the defect. In this case, the transparent electrode 190 may be connected to the case by a conductive tape.

5 is a cross-sectional view of an active matrix organic LED according to a second embodiment of the present invention. The second embodiment of the present invention has the same structure as the first embodiment except for the transparent electrode and the circular polarizer. , The same reference numerals are assigned to the same parts, and description thereof will be omitted.

As shown in FIG. 5, in the second embodiment of the present invention, the transparent electrode 200 is formed on the transparent substrate 110, and the circular polarizer 210 is formed on the transparent electrode 200. The transparent electrode 200 may be formed of a material such as ITO, and may be formed by coating on the substrate 110 or depositing by sputtering.

Alternatively, the organic LED according to the second embodiment of the present invention may be formed by attaching the transparent electrode 200 and the circular polarizer 210 integrally formed on the substrate 110 as shown in FIG. 6.

In the first and second embodiments of the present invention, an active matrix organic LED including a thin film transistor has been described. However, the structure may be applied to a passive matrix organic LED that does not include a thin film transistor.

Meanwhile, in the present invention, the transparent electrode may be formed by using a conductive polymer other than ITO. The structure of the conductive polymer is illustrated with reference to FIGS. 7A to 7F, respectively.

FIG. 7A shows poly (3,4-ethylenedioxithiophene) (PEDOT), FIG. 7B shows poly aniline, and FIG. 7C shows polyacetylene. (poly acetylene), FIG. 7D shows poly paraphenylene, FIG. 7E shows poly pyrrole, and FIG. 7F shows poly thiophene.

The present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit of the present invention.

In the present invention, the circular polarizer is attached to one surface of the organic LED to improve visibility, and a transparent electrode is formed on the upper or lower portion of the circular polarizer to prevent the generation of static electricity and prevent defects caused by static electricity.

Claims (8)

Transparent insulating substrates; A first electrode formed on a lower surface of the substrate and serving as a hole supply layer; An organic emission layer below the first electrode; A second electrode formed under the organic emission layer and serving as an electron supply layer; A circular polarizer disposed on an upper surface of the substrate; A transparent electrode formed on the circular polarizer Organic electroluminescent device comprising a. Transparent insulating substrates; A first electrode formed on a lower surface of the substrate and serving as a hole supply layer; An organic emission layer below the first electrode; A second electrode formed under the organic emission layer and serving as an electron supply layer; A transparent electrode on an upper surface of the substrate; A circular polarizer disposed on the transparent electrode; Organic electroluminescent device comprising a. The method according to claim 1 or 2, And said circular polarizer and said transparent electrode are integrally formed. The method according to claim 1 or 2, The transparent electrode is an organic electroluminescent device consisting of indium tin oxide. The method of claim 4, wherein The transparent electrode is an organic electroluminescent device formed by a coating method. The method of claim 4, wherein The transparent electrode is an organic electroluminescent device deposited by a sputtering method. The method according to claim 1 or 2, The transparent electrode is an organic electroluminescent device comprising any one of poly (3,4-ethylenedioxythiophene), polyaniline, polyacetylene, poly paraphenylene, polypyrrole and polythiophene. The method according to claim 1 or 2, An organic electroluminescent device further comprising a thin film transistor connected to the first electrode.