KR100781594B1 - an active matrix organic electroluminescence display and a manufacturing method of the same - Google Patents

Abstract

The present invention relates to an active matrix organic electroluminescent device using a thin film transistor.

In the organic electroluminescent device according to the present invention, it is possible to obtain a uniform brightness by arranging a diffusion film in a direction in which light is emitted. In this case, the brightness of the front direction may be increased by further using a prism sheet. The diffusion film and the prism sheet can be used for both top emission and back emission methods, and when the top emission method is used, a device having a high aperture ratio and a long lifetime can be obtained.

On the other hand, in the case of using the top emission method to form a protective layer to protect the organic light emitting layer, at this time, by forming a protective layer having a predetermined thickness protective layer and irregularities, respectively, to improve the brightness in the front direction, luminous efficiency is improved It can also increase power consumption.

Organic electroluminescent element, aperture ratio, luminance, front emission, back emission, irregularities

Description

Active matrix organic electroluminescence display and a manufacturing method of the same             

1 is a circuit diagram of one pixel of a conventional active matrix organic electroluminescent device.

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

3 is a diagram showing luminance in a conventional active matrix organic electroluminescent device.

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

5A to 5J are cross-sectional views illustrating a manufacturing process of an active matrix organic electroluminescent device according to the present invention.

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

7 to 10 are cross-sectional views of active matrix organic electroluminescent devices according to third to sixth embodiments, respectively.

<Description of Symbols for Main Parts of Drawings>

100 substrate 110 buffer layer                 

121: active layer 122: drain region

123: source region 125: capacitor electrode

130: gate insulating film 131: gate electrode

140: first interlayer insulating film 151: power line

160: second interlayer insulating film 161, 162, 163: contact hole

171: source electrode 172: drain electrode

180: first protective layer 181: fourth contact hole

190: first electrode 200: second protective layer

201: bank 210: organic light emitting layer

220: second electrode 230: third protective layer

240: fourth protective layer

The present invention relates to an organic electroluminescent device, and more particularly, to an active matrix organic electroluminescent device using a thin film transistor.

Currently, a cathode ray tube (CRT) is used as a main device in a display device such as a television or a monitor, but this has a problem of weight and volume and high driving voltage. Accordingly, there is a need for a flat panel display having excellent characteristics such as thinness, light weight, and low power consumption, and has emerged, such as a liquid crystal display, a plasma display panel, and an electric field emission. Various flat panel display devices such as a field emission display and an electroluminescent display (or electroluminescence display (ELD)) have been researched and developed.

The dual electroluminescent device is a display device using an electroluminescence (EL) phenomenon in which light is generated when a certain electric field is applied to a phosphor, and an inorganic electroluminescent device and an organic electroluminescent device depending on a source causing excitation of carriers. (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.                         

An active matrix type 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 a flat panel display device, and an active matrix organic electroluminescent device is applied to an organic electroluminescent device. It will be described with reference to the accompanying drawings.

FIG. 1 illustrates a circuit structure of one pixel of an active matrix organic electroluminescent device, and as illustrated, one pixel of the active matrix organic electroluminescent device includes a switching thin film transistor 4 and a driving thin film. It consists of a transistor 5, a storage capacitor 6, and a light emitting diode 7.

Here, the gate electrode of the switching thin film transistor 4 is connected to the gate wiring 1, and the source electrode is connected to the data wiring 2. The drain electrode of the switching thin film transistor 4 is connected to the gate electrode of the driving thin film transistor 5, and the drain electrode of the driving thin film transistor 5 is connected to the anode electrode of the light emitting diode 7. The source electrode of the driving thin film transistor 5 is connected to the power line 3, and the cathode electrode of the light emitting diode 7 is grounded. Next, the storage capacitor 6 is connected to the gate electrode and the source electrode of the driving thin film transistor 5.

Therefore, when a signal is applied through the gate wiring 1, the switching thin film transistor 4 is turned on, and an image signal from the data wiring 2 is transferred to the storage capacitor 6 through the switching thin film transistor 4. Stored. The image signal is transmitted to the gate electrode of the driving thin film transistor 5 to operate the driving thin film transistor 5 to output light through the light emitting diode 7, by controlling the current flowing through the light emitting diode 7. Adjust the brightness. Here, since the driving thin film transistor 5 is driven by the voltage value stored in the storage capacitor 6 even when the switching thin film transistor 4 is turned off, the current is continuously emitted until the image signal of the next screen is input. It flows into the diode 7 and emits light.

As such, a cross-sectional view of a conventional active matrix organic electroluminescent device using a thin film transistor is illustrated in FIG. 2, which is a cross-sectional view of a driving thin film transistor, a light emitting diode, and a storage capacitor.

As shown, a buffer layer 11 is formed on the substrate 10, and the first and second polycrystalline silicon layers 12a, 12b, 12c, 13a having an island shape thereon are formed thereon. Formed. The first polycrystalline silicon layers 12a, 12b, and 12c are divided into the active layer 12a of the thin film transistor, the drain region 12b and the source region 12c doped with impurities, and the second polycrystalline silicon layer 13a is It becomes a capacitor electrode.

Next, a gate insulating film 14 is formed on the active layer 12a, and a gate electrode 15 is formed thereon.

Subsequently, a first interlayer insulating layer 16 is formed on the gate electrode 15 to cover the gate electrode 15, the source and drain regions 12c and 12b, and the capacitor electrode 13a, and the upper portion of the capacitor electrode 13a. The power line 17 is formed on the first interlayer insulating film 16. Here, the power line 17 has a form of wiring and extends long in one direction.                         

Next, a second interlayer insulating layer 18 is formed on the power line 17. The second interlayer insulating layer 18 is formed of the drain region 12b and the source region 12c together with the first interlayer insulating layer 16. The first and second contact holes 18a and 18b respectively reveal a part, and the third contact hole 18c partially exposes the power line 17.

Next, a drain electrode 19a and a source electrode 19b are formed on the second interlayer insulating film 18. Here, the drain electrode 19a is connected to the drain region 12b through the first contact hole 18a, and the source electrode 19b is connected to the source region 12c through the second and third contact holes 18b and 18c. ) And power line 17, respectively.

Subsequently, a first passivation layer 20 is formed on the drain electrode 19a and the source electrode 19b, and the first passivation layer 20 has a fourth contact hole 20a partially exposing the drain electrode 19a. Has

Next, a first electrode 21 made of a transparent conductive material is formed on the first protective layer 20, and a second protective layer 22 is formed thereon. The second protective layer 22 has a bank 22a partially exposing the first electrode 21.

Next, an organic light emitting layer 23 is formed on the bank 22a of the second protective layer 22, and a second electrode 24 made of an opaque conductive material such as metal is formed thereon. Here, the second electrode 24 is formed on the entire substrate.

In the active matrix organic electroluminescent device of FIG. 2, since the first electrode 21 is made of a transparent conductive material, and the second electrode 24 is made of an opaque conductive material, the light in the organic light emitting layer 23 is the first electrode. It is to be discharged downward through 23. Accordingly, a bottom emission method is used, and elements such as thin film transistors and storage capacitors are formed in the pixel area, and thus light passes only to portions except these, so that the aperture ratio is lowered.

Recently, an organic electroluminescent device having a top emission method has been proposed to increase the aperture ratio. In the case of the top emission type, the aperture ratio is high, and thus the life of the device may be improved, but device efficiency may be deteriorated. In addition, the power consumption has a value similar to that of the back-emitting type.

On the other hand, since the organic electroluminescent device performs current driving, the luminance is uneven as shown in FIG. 3 due to the resistance of the wiring.

The present invention has been made to solve the above object, and an object of the present invention is to provide an active matrix organic electroluminescent device having a high aperture ratio and a long lifetime.

Another object of the present invention is to provide an active matrix organic electroluminescent device which can reduce power consumption by improving luminous efficiency.

Still another object of the present invention is to provide an active matrix organic electroluminescent device having a uniform brightness.

In the active matrix organic electroluminescent device according to the present invention for achieving the above object, a thin film transistor is formed on a lower surface of a transparent insulating substrate, is connected to the thin film transistor, and a transparent first electrode is formed. An organic emission layer is formed below the first electrode, and an opaque second electrode is formed below the organic emission layer. Next, a first diffusion film is disposed on the upper surface of the substrate, and a circular polarizer is disposed thereon.

The first prism sheet, the second prism sheet, and the second diffusion film may be further disposed between the first diffusion film and the circular polarizer, or the organic emission layer and the refractive index may be interposed between the organic emission layer and the second electrode. It may further include another insulating layer.

In another active matrix organic electroluminescent device of the present invention, a thin film transistor is formed on a transparent insulating substrate, and a first electrode which is connected to the thin film transistor and is opaque is formed. Subsequently, an organic emission layer is formed on the first electrode, and a transparent second electrode is formed on the organic emission layer. Next, a protective layer is formed on the upper portion of the second electrode, and the first diffusion film, the first prism sheet, the second prism sheet, and the second diffusion film are sequentially disposed thereon.

Here, the first prism sheet and the second prism sheet are preferably arranged so that the prism shape is perpendicular to each other.

In addition, the first diffusion film includes a particulate resin and may be made of one of a transparent polycarbonate and a polyester.

In another active matrix organic electroluminescent device according to the present invention, a thin film transistor is formed on a substrate, and a storage capacitor is connected to the thin film transistor. Subsequently, a first protective layer covers the thin film transistor and the storage capacitor, and a first electrode connected to the thin film transistor is formed on the first protective layer. Next, a second protective layer having a bank exposing the first electrode is formed on the first electrode, and an organic light emitting layer is formed on the bank. Next, a second electrode made of a transparent conductive material is formed on the organic light emitting layer, and a third protective layer and a fourth protective layer are sequentially formed on the second electrode, and the fourth protective layer has an uneven surface. have.

Here, the unevenness may be made in the form of a triangle, or may be made in the shape of a hemisphere.

In addition, the second electrode may be made of indium tin oxide.

In the method of manufacturing an active matrix organic electroluminescent device according to the present invention, a thin film transistor is formed on a substrate, and a storage capacitor connected to the thin film transistor is formed. Subsequently, after the first protective layer is formed on the thin film transistor and the storage capacitor, a first electrode connected to the thin film transistor using an opaque conductive material is formed thereon. Next, a second protective layer having a bank exposing the first electrode is formed on the first electrode, and an organic light emitting layer is formed on the bank. Next, a second electrode made of a transparent conductive material is formed on the organic emission layer, and a third passivation layer and a fourth passivation layer each having a concave-convex shape are formed thereon.

In the present invention, the unevenness may be formed using plasma ashing, wherein the unevenness may form a triangular shape.

In addition, the unevenness may be formed by heat treatment after plasma ashing, wherein the unevenness may be formed in a hemispherical shape.

Meanwhile, the second electrode may be made of indium tin oxide.

As described above, in the organic electroluminescent device according to the present invention, uniform luminance may be obtained using a diffusion film, and in this case, the luminance of the front direction may be increased by further using a prism sheet. The diffusion film and the prism sheet can be used for both top emission and back emission methods, and when the top emission method is used, a device having a high aperture ratio and a long lifetime can be obtained.

On the other hand, in the case of using the top emission method to form a protective layer to protect the organic light emitting layer, at this time, by forming a protective layer having a predetermined thickness protective layer and irregularities, respectively, to improve the brightness in the front direction, luminous efficiency is improved It can also increase power consumption.

Hereinafter, an active matrix organic electroluminescent device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

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

As shown, a buffer layer 110 made of a material such as a silicon oxide film is formed on the insulating substrate 100, and the first and second polycrystalline silicon layers 121, 122, 123, and 125 having an island shape thereon are formed thereon. Is formed. The first polycrystalline silicon layers 121, 122, and 123 are divided into an active layer 121 of the thin film transistor, a drain region 122 and a source region 123 doped with impurities, and the second polycrystalline silicon layer 125 is It becomes a capacitor electrode.

Next, a gate insulating layer 130 formed of a material such as a silicon oxide film is formed on the active layer 121, and a gate electrode 131 is formed thereon.

Subsequently, a first interlayer insulating layer 140 is formed on the gate electrode 131 to cover the gate electrode 131, the source and drain regions 122 and 123, and the capacitor electrode 125, and the upper portion of the capacitor electrode 125. The power line 151 is formed on the first interlayer insulating layer 140. Here, the power line 151 has a form of wiring and extends in one direction and forms a storage capacitor together with the capacitor electrode 125.

Next, a second interlayer insulating layer 160 is formed on the power line 151. The second interlayer insulating layer 160 is formed along with the first interlayer insulating layer 140 and the first and second contact holes 161 and 162. And a third contact hole 163 partially exposing the power line 151. Here, the first contact hole 161 exposes the source region 123, and the second contact hole 162 exposes the drain region 122.

Next, a source electrode 171 and a drain electrode 172 are formed on the second interlayer insulating layer 160. Here, the source electrode 171 is connected to the source region 123 through the first contact hole 161, and is connected to the power line 151 through the third contact hole 163, and the drain electrode 172 is It is connected to the drain region 122 through the first contact hole 161.

Subsequently, a first passivation layer 180 is formed on the source and drain electrodes 171 and 172, and the first passivation layer 180 has a fourth contact hole 181 partially exposing the drain electrode 172. .

Next, a first electrode 190 made of an opaque conductive material is formed on the first passivation layer 180, and a second passivation layer 200 is formed thereon. The second protective layer 200 has a bank 201 exposing the first electrode 190.

Next, an organic emission layer 210 is formed on the bank 201 of the second protective layer 200, and a second electrode 220 made of a transparent conductive material is formed thereon. Here, the second electrode 220 is formed on the entire surface of the substrate, and may be made of a material such as indium-tin-oxide (hereinafter referred to as ITO).

Subsequently, a third passivation layer 230 is formed on the second electrode 220. The third passivation layer 230 serves to protect the organic light emitting layer 210 which is vulnerable to moisture. The third protective layer 230 may be made of a material such as benzocyclobutene, photo-acryl, silicon oxide film, or silicon nitride film. The material may be formed of the organic light emitting layer 210 and the refractive index and the light absorption coefficient. Since the light emission spectrum varies depending on the thickness. Therefore, it is desirable to have a thickness capable of increasing color purity and luminance.

Next, a fourth passivation layer 240 is formed on the third passivation layer 230, and the fourth passivation layer 240 has irregularities such as a triangular shape on the top surface. The unevenness serves to collect the light emitted radially from the organic light emitting layer 210 to collect in the main viewing angle direction, that is, the front direction, so as to increase the luminance in the front direction.                     

As described above, in the first embodiment of the present invention, since the first electrode 190 is made of a transparent conductive material and the second electrode 220 is made of an opaque conductive material, light from the organic light emitting layer 210 is transmitted to the second electrode. Through the 220, the top emission is achieved. Therefore, an element having a high aperture ratio and a long lifetime can be obtained. At this time, a third protective layer 230 having a predetermined thickness and a fourth protective layer 240 having irregularities are formed on the second electrode 220, and the light is collected in the front direction, thereby improving luminance and emitting light. Higher efficiency can reduce power consumption.

5A to 5J illustrate the manufacturing process of the active matrix organic electroluminescent device according to the first embodiment of the present invention.

As shown in FIG. 5A, after the buffer layer 110 is formed on the insulating substrate 100 and polycrystalline silicon is formed thereon, the semiconductor layers 126 and 127 having an island shape are formed by patterning the buffer layer 110.

Next, as illustrated in FIG. 5B, an insulating film such as a silicon oxide film is deposited on the semiconductor layers 126 and 127, and a conductive material such as a metal is deposited thereon, followed by patterning, thereby forming the gate insulating film 130 and the gate electrode ( 131). Subsequently, impurities are implanted into the semiconductor layers (126 and 127 of FIG. 5A) using the gate electrode 131 as a mask, such as by ion doping, so that the active layer 121 where the impurities are not implanted and the drain region where the impurities are implanted ( 122 and source region 123 and capacitor electrode 125 are formed. Here, the drain region 122 and the source region 123 are located at both sides of the active layer 121.

Next, as illustrated in FIG. 5C, a first interlayer insulating layer 140 is formed on the gate electrode 131, a conductive material such as a metal is deposited on the gate electrode 131, and then patterned to form a power line 151 on the capacitor electrode 125. ). The power line 151 forms a storage capacitor with the capacitor electrode 125.

Subsequently, as illustrated in FIG. 5D, the first to third contact holes 161, 162 and 163 are formed by forming and patterning the second interlayer insulating layer 160 on the power line 151. The first contact hole 161 exposes the source region 123, the second contact hole 162 exposes the drain region 122, and the third contact hole 163 exposes the power line 125, respectively.

Next, as illustrated in FIG. 5E, a conductive material such as a metal is deposited and patterned on the second interlayer insulating layer 160 to form a drain electrode 172 and a source electrode 171. The source electrode 171 is connected to the source region 123 and the power line 151 through the first and third contact holes 161 and 163, respectively, and the drain electrode 172 opens the second contact hole 162. It is connected to the drain region 122 through.

Next, as illustrated in FIG. 5F, a fourth protective hole 181 is formed on the drain electrode 172 and the source electrode 171, and is patterned to expose the drain electrode 172. To form.

Subsequently, as illustrated in FIG. 5G, a transparent conductive material is deposited and patterned to form a first electrode 190 connected to the drain electrode 172 through the fourth contact hole 181. Here, the first electrode 190 is made of an opaque conductive material such as metal.

Next, as shown in FIG. 5H, the second protective layer 200 is formed and patterned on the first electrode 190 to form a bank 201 exposing the first electrode 190.

Next, as illustrated in FIG. 5I, an organic emission layer 210 is formed on the bank 201 of the second protective layer 200, and a transparent conductive material such as ITO is deposited thereon to form the second electrode 220. Form.

Subsequently, as shown in FIG. 5J, a third protective layer 230 is formed, and a fourth protective layer 240 is formed thereon. In this case, the fourth passivation layer 240 has irregularities on the surface. The formation of the irregularities may be performed by removing a part of the surface of the fourth passivation layer 240 by a method such as plasma ahing.

In the above embodiment, the upper surface has a concave-convex shape of a triangular shape, but may be formed in another shape.

An active matrix organic electroluminescent device according to a second embodiment of the present invention is illustrated in FIG. 6. Here, since it has the same structure as the first embodiment except for the fourth protective layer portion, a description thereof will be omitted.

As shown in FIG. 6, in the second embodiment of the present invention, the surface of the fourth protective layer 250 has hemispherical irregularities, and the hemispherical irregularities are organic materials and the fourth protective layer 250 is formed. And the surface of the fourth protective layer 250 may be partially removed by a method such as plasma ashing, and then heat-treated to form the surface of the irregularities.

On the other hand, by improving the contrast ratio of the organic electroluminescent device by using a circular polarizer (visibility: visibility, which is the degree to which the color is easily seen) can be improved.

This third embodiment is shown in FIG. 7, which shows that the light emitting part is arranged upward as a back emission method.

As illustrated, a plurality of thin film transistors T1 are formed under the transparent substrate 310. The thin film transistors T1 are formed of a gate electrode 321 and source and drain electrodes 322 and 323, and are polycrystalline. An active layer 331 made of silicon is included. Here, the substrate 310 is preferably made of a transparent substrate, such as a glass substrate.

Next, a protective layer 340 having a contact hole exposing the drain electrode 323 of the thin film transistor T1 is formed under the thin film transistor T1, and a first electrode 351 is formed under the protective layer 340. Formed. The first electrode 351 is connected to the drain electrode 323 and is preferably made of a transparent conductive material as the hole supply layer, and may be made of a material such as ITO.

Subsequently, an organic emission layer 360 is formed under the first electrode 351. Although the organic light emitting layer 360 is illustrated as being formed over the entire surface of the substrate 310, the organic light emitting layer 360 may be patterned to correspond one-to-one with the first electrode 351.

Next, a second electrode 370 made of an opaque conductive material such as a metal is formed under the organic light emitting layer 360, and the second electrode 370 supplies electrons to the organic light emitting layer 360.

Meanwhile, a diffusion film 380 is disposed on the substrate 310 to scatter and collect light emitted from the organic light emitting layer 360. The diffusion film 380 is disposed on the diffusion film 380 to improve visibility of the organic electroluminescent device. The circularly polarized light 390 for raising is arrange | positioned. Here, the diffusion film 380 may be coated with a particulate resin for scattering and condensing light on a transparent polycarbonate or a polyester film.

Therefore, in the third embodiment of the present invention, the diffusion film may be disposed between the circular polarizer and the substrate to have uniform luminance.

In addition, a prism sheet may be disposed between the circular polarizer and the substrate of the organic electroluminescent device to further collect the light. A fourth embodiment of the present invention is illustrated in FIG. 8. Since the fourth embodiment of the present invention has a structure substantially similar to the foregoing third embodiment, the same reference numerals are used for the same parts, and description thereof will be omitted.

As illustrated, the first diffusion film 410 is disposed on the transparent insulating substrate 310, and the first prism sheet 420 and the second prism sheet 430 are disposed thereon, respectively. Here, the first diffusion film 410 prevents defects such as scratches generated by the prism sheets 420 and 430 in direct contact with the substrate 310, and evenly diffuses the light emitted from the organic light emitting layer 360. To function. In addition, the first and second prism sheets 420 and 430 serve to collect light in a direction perpendicular to the sheet with the upper surface of the prism shape, wherein the first and second prism sheets 420 and 430 The prism shapes are arranged perpendicular to each other.

Next, the second diffusion film 440 and the circular polarizer 450 are sequentially disposed on the second prism sheet 430. The second diffusion film 440 scatters and condenses the light passing through the second prism sheet 430 to have a uniform brightness.

Here, the upper circular polarizer 450 may be omitted.

Meanwhile, a fifth embodiment of the present invention is illustrated in FIG. 9, wherein an insulating layer 510 having a different refractive index is inserted between the organic light emitting layer 360 and the second electrode 370 to increase rear luminance by an external light source. You can also eliminate

In the above-described third to fifth embodiments, the case of the back light emission has been described, but this may also be applied to the top light emission method.

10 illustrates a sixth embodiment of the present invention. As shown in FIG. 10, a plurality of thin film transistors T2 are formed on a transparent first substrate 610, and the thin film transistors T2 are formed on the gate electrode 621. And source and drain electrodes 622 and 623, and an active layer 631 made of polycrystalline silicon. Here, the first substrate 610 may be made of a transparent substrate, such as a glass substrate, or may be made of an opaque substrate.

Next, a protective layer 640 having a contact hole exposing the drain electrode 623 of the thin film transistor T2 is formed on the thin film transistor T2, and the first electrode 651 is formed on the protective layer 640. Formed. The first electrode 651 is connected to the drain electrode 623 and is preferably made of an opaque conductive material such as metal.

Next, an organic emission layer 660 is formed on the first electrode 651. Although the organic light emitting layer 660 is illustrated as being formed over the entire surface of the substrate, the organic light emitting layer 660 may be patterned to correspond one-to-one with the first electrode 651.

Next, a second electrode 670 made of a transparent conductive material is formed on the organic emission layer 660, and the second electrode 670 may be made of a material such as ITO.

Next, a buffer layer 680 for protecting the organic emission layer 660 is formed on the second electrode 670, and a transparent second substrate 690 is disposed thereon, which may be omitted.

Subsequently, the first diffusion film 710 is disposed on the second substrate 690, and the first prism sheet 720 and the second prism sheet 730 are disposed thereon, respectively. Here, the first and second prism sheets 720 and 730 are arranged such that the prism shapes are perpendicular to each other.

Next, a second diffusion film 740 is disposed on the second prism sheet 730. Although not shown, a circular polarizer may be further disposed on the second diffusion film 730.

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 organic electroluminescent device according to the present invention, a uniform brightness can be obtained using a diffusion film, and the brightness of the front direction can be increased by further using a prism sheet.

The diffusion film and the prism sheet can be used for both top emission and back emission methods, and when the top emission method is used, a device having a high aperture ratio and a long lifetime can be obtained.

On the other hand, in the case of using the top emission method to form a protective layer to protect the organic light emitting layer, at this time, by forming a protective layer having a predetermined thickness protective layer and irregularities, respectively, to improve the brightness in the front direction, luminous efficiency is improved It can also increase power consumption.

Claims (16)

Transparent insulating substrates; A thin film transistor formed on the bottom surface of the substrate; A first electrode connected to the thin film transistor and transparent; An organic emission layer below the first electrode; An opaque second electrode formed under the organic light emitting layer; A first diffusion film disposed on an upper surface of the substrate; A circular polarizer disposed on the first diffusion film Active matrix organic electroluminescent device comprising a. The method of claim 1, An active matrix organic electroluminescent device further comprising a first prism sheet, a second prism sheet, and a second diffusion film, which are sequentially disposed between the first diffusion film and the circular polarizer. The method of claim 2, And an insulation layer having a refractive index different from that of the organic light emitting layer between the organic light emitting layer and the second electrode. Transparent insulating substrates; A thin film transistor formed on the substrate; An opaque first electrode connected to the thin film transistor; An organic light emitting layer on the first electrode; A second electrode formed on the organic emission layer and transparent; A protective layer on the second electrode; A first diffusion film disposed on the protective layer; A first prism sheet disposed on the first diffusion film; A second prism sheet on the first prism sheet A second diffusion film disposed on the second prism sheet Active matrix organic electroluminescent device comprising a. The method according to claim 2 or 4, And the first prism sheet and the second prism sheet are arranged such that the prism shape is perpendicular to each other. The method according to claim 2 or 4, The first diffusion film comprises a particulate resin, and an active matrix organic electroluminescent device comprising one of transparent polycarbonate and polyester. Board; A thin film transistor formed on the substrate; A storage capacitor connected to the thin film transistor; A first protective layer covering the thin film transistor and the storage capacitor; A first electrode formed on the first passivation layer and connected to the thin film transistor; A second protective layer having a bank overlying the first electrode to expose the first electrode; An organic light emitting layer formed on the bank; A second electrode formed on the organic emission layer and made of a transparent conductive material; A third protective layer over the second electrode; A fourth protective layer formed on the third protective layer, the surface of the fourth protective layer Active matrix organic electroluminescent device comprising a. The method of claim 7, wherein The irregularities are triangular active matrix organic electroluminescent device. The method of claim 7, wherein The unevenness is an active matrix organic electroluminescent device consisting of a hemisphere. The method of claim 7, wherein The second electrode is an active matrix organic electroluminescent device consisting of indium tin oxide. Forming a thin film transistor on the substrate; Forming a storage capacitor connected to the thin film transistor; Forming a first passivation layer on the thin film transistor and the storage capacitor; Forming a first electrode connected to the thin film transistor with an opaque conductive material on the first protective layer; Forming a second protective layer on the first electrode, the second protective layer having a bank exposing the first electrode; Forming an organic emission layer on the bank; Forming a second electrode made of a transparent conductive material on the organic emission layer; Forming a third passivation layer on the second electrode; Forming a fourth passivation layer formed on an upper surface of the third passivation layer in an uneven shape; Method for manufacturing an active matrix organic electroluminescent device comprising a. The method of claim 11, The uneven surface of the fourth protective layer is a method of manufacturing an active matrix organic electroluminescent device formed by using plasma ashing. The method of claim 12, The irregularities are triangular shape active matrix organic electroluminescent device manufacturing method. The method of claim 11, The unevenness of the surface of the fourth protective layer is plasma ashing, and the heat treatment step is formed by the active matrix organic electroluminescent device manufacturing method. The method of claim 14, The unevenness is a manufacturing method of an active matrix organic electroluminescent device having a hemispherical shape. The method of claim 11, The second electrode is a method of manufacturing an active matrix organic electroluminescent device consisting of indium tin oxide.

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