KR20120041459A - White organic light emitting display device and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A white organic electroluminescent and a manufacturing method thereof are provided to prevent radiation problems at a light non-emitting area by compartmentalizing a carrier generating layer into a light emitting area and the light non-emitting area. CONSTITUTION: A transistor part(TFT) is formed on a substrate(110). A first electrode(120) is connected to a source electrode or a drain electrode of a driving transistor included in the transistor part. A first bank layer(121) comprises a first opening part which exposes a part of the first electrode. A second bank layer(122) comprises a second opening part which exposes a part of the first bank layer. A first organic light-emitting layer(123) is formed on an area of the first bank layer and an area of the second bank layer. A second organic light-emitting layer(124) is formed in order to cover the first organic light-emitting layer.

Description

White Organic Light Emitting Display Device and Manufacturing Method thereof

Embodiments of the present invention relate to a white organic light emitting display device and a method of manufacturing the same.

An organic light emitting display device used in an organic light emitting display device is a self-light emitting device having a light emitting layer formed between two electrodes positioned on a substrate. The organic light emitting display includes a top emission type, a bottom emission type, or a dual emission type according to a direction in which light is emitted. The organic light emitting display device is divided into a passive matrix type and an active matrix type according to a driving method.

An organic light emitting display device includes a white organic light emitting display device that emits white light using at least two organic light emitting layers. In the white organic light emitting display device, since the organic light emitting layer emits white light, a color filter for converting the light into red, green, and blue (RGB) is used. The subpixels disposed in the white organic light emitting display device may include a transistor unit including a switching transistor, a driving transistor, and a capacitor, and a first electrode, a first organic light emitting layer, a second organic light emitting layer, and a second electrode connected to the driving transistor included in the transistor unit. It includes a light emitting unit including an electrode. In the white organic light emitting display device having the above structure, when a scan signal, a data signal, and a power are supplied to a plurality of subpixels arranged in a matrix form, the selected subpixel emits white light, and the color filter emits RGB colors. In this way, an image can be displayed.

Meanwhile, in the white organic light emitting display device, two first and second organic light emitting layers (first stack, second stack) are composed of two stack structures, and a carrier generation layer is formed between the two stacks. ; CGL). However, in the conventional white organic light emitting display device using the carrier generation layer, the carrier generation layer formed in the non-emission area and the interference between the subpixels according to the increase in the thickness of the carrier generation layer are included in the two stacks as the anode electrode. Light is emitted from organic materials. As such, when the carrier generating layer functions as an anode electrode in the non-light emitting area, there is a problem that display quality is deteriorated due to interference between subpixels as well as generation of mixed colors between subpixels due to light emission in the non-light emitting area. .

According to an embodiment of the present invention for solving the above-mentioned problems, the carrier generating layer CGL is formed by dividing the light emitting area into the non-light emitting area, thereby preventing the light emission problem in the non-light emitting area and generating mixed colors between subpixels. In addition, the present invention provides a white organic light emitting display device and a method of manufacturing the same, which can solve the problem of deterioration of display quality due to interference between subpixels.

Embodiments of the present invention as a means for solving the above problems, the substrate; A transistor unit formed on the substrate; A first electrode connected to the source or drain electrode of the driving transistor included in the transistor unit; A first bank layer having a first opening that exposes a portion of the first electrode; A second bank layer having a second opening that exposes a portion of the first bank layer; A first organic light emitting layer formed in a region of the first electrode and a region of the second bank layer and including one light emitting material; A second organic light emitting layer formed to cover the first organic light emitting layer and including two light emitting materials; And a second electrode formed to cover the second organic light emitting layer.

The first bank layer may have a reverse taper shape in which a region covering a portion of the first electrode is drawn inwardly.

The second bank layer may have a regular taper shape that occupies a narrower area than the first bank layer and has a gentle inclination toward the region exposing the first electrode.

The first bank layer may be formed of an inorganic material, and the second bank layer may be formed of an organic material.

The thickness of the second bank layer may be thicker than the thickness of the first bank layer.

The first organic light emitting layer includes a first hole injection layer formed on the first electrode, a first hole transport layer formed on the hole injection layer, a second hole transport layer formed on the first hole transport layer, and a second hole transport layer. And a first light emitting layer including one light emitting material, a first electron transport layer formed on the first light emitting layer, and a carrier generating layer formed on the electron transport layer.

The second organic light emitting layer includes: a second hole injection layer formed on the carrier generation layer, a third hole transport layer formed on the second hole injection layer, and a second hole injection layer formed on the third hole transport layer and including two light emitting materials. It may include a light emitting layer, a second electron transport layer formed on the second light emitting layer, and an electron injection layer formed on the second electron transport layer.

In another aspect, an embodiment of the present invention, forming a transistor unit including a color filter on a substrate; Forming a first electrode connected to a source or drain electrode of a driving transistor included in the transistor unit on the transistor unit; Forming a first bank layer having a first opening that exposes a portion of the first electrode; Forming a second bank layer having a second opening that exposes a portion of the first bank layer; Forming a first organic light emitting layer including one light emitting material in a region of the first electrode and a region of the second bank layer; Forming a second organic light emitting layer including two light emitting materials to cover the first organic light emitting layer; And forming a second electrode to cover the second organic light emitting layer.

The first bank layer is formed to have an inverse taper shape in which a region covering a portion of the first electrode is drawn inward, and the first organic light emitting layer is formed of the region of the first electrode and the second bank by the inverse taper shape of the first bank layer. It can be formed divided into regions of the layer.

The thickness of the second bank layer may be thicker than the thickness of the first bank layer.

According to the embodiment of the present invention, since the carrier generating layer CGL is formed by dividing the light emitting area and the non-light emitting area, it is possible to prevent the light emission problem in the non-light emitting area and to display color due to the interference between the subpixels as well as the occurrence of color mixing between the subpixels. There is an effect of providing a white organic light emitting display device and a method for manufacturing the same, which can solve this deterioration problem.

1 is a schematic block diagram of a white organic light emitting display device;
2 is a cross-sectional view of a subpixel of a white organic light emitting display device according to an exemplary embodiment of the present invention.
3 is an enlarged view of a region A1 shown in FIG. 2;
4 is an enlarged view of the area A2 shown in FIG.
5 to 8 are views for explaining a method of manufacturing an organic light emitting display device according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, the specific content for the practice of the present invention will be described.

1 is a schematic block diagram of a white organic light emitting display device.

As illustrated in FIG. 1, the white organic light emitting display device includes a timing controller TCN, a data driver DVB, a scan driver SDRV, a power supply PWR, and a panel PNL.

The timing controller TCN controls the data driver DDRV using the data driver signal DDC, and simultaneously controls the scan driver SDRV using the gate driver signal GDC. In addition, the timing controller TCN converts the image signal supplied from the outside into the data signal DATA and supplies it to the data driver DDR. The timing controller TCN may be mounted on a printed circuit board connected to the panel PNL in the form of an integrated circuit (IC).

The data driver DDRV supplies the data signal DATA generated under the control of the timing controller TCN to the subpixel SP through the data wiring DL1..DLn formed in the panel PNL. The data driver DDRV may be mounted on the panel PNL in the form of an IC.

The scan driver SDRV supplies the scan signal generated under the control of the timing controller TCN to the subpixel SP through the scan wiring SL1 .. SLm formed in the panel PNL. The scan driver SDRV may be mounted on the panel PNL in the form of an IC or formed on the panel PNL in the form of a gate in panel (GIP).

The power supply unit PWR generates a high potential power VDD and a low potential power GND, and supplies the same to at least one of the timing controller TCN, the data driver DVB, the scan driver SDRV, and the panel PNL. . The power supply unit PWR may be mounted on a printed circuit board connected to the panel PNL.

The panel PNL includes subpixels SP arranged in a matrix form on a substrate. The subpixel SP includes a switching transistor for transmitting a data signal to a capacitor in response to a scan signal, a capacitor for storing the data signal as a data voltage, and a driving transistor for generating a driving current according to the data voltage stored in the capacitor. A transistor unit and an organic light emitting diode unit which emits light according to a driving current generated from the driving transistor.

Hereinafter, a subpixel structure of a white organic light emitting display device according to an embodiment of the present invention will be described in more detail.

2 is a cross-sectional view of a subpixel of a white organic light emitting display device according to an exemplary embodiment of the present invention, FIG. 3 is an enlarged view of an area A1 shown in FIG. 2, and FIG. 4 is an enlarged view of an area A2 shown in FIG. 2. It is an enlarged view.

As illustrated in FIG. 2, a subpixel according to an exemplary embodiment of the present invention includes a transistor TFT formed on the substrate 110 and an organic light emitting diode OLED.

The buffer layer 111 is formed on the substrate 110. The buffer layer 111 may be formed to protect the transistor unit TFT formed in a subsequent process from impurities such as alkali ions flowing out of the substrate 110, but this may be omitted.

First and second active layers 112a and 112b are formed on the buffer layer 111. The first and second active layers 112a and 112b include source, channel and drain regions, and the source / drain regions are doped with P-type or N-type impurities.

The first insulating layer 113 covering the first and second active layers 112a and 112b is formed on the substrate 110. The first insulating layer 113 is formed of silicon oxide (SiOx), silicon nitride (SiNx), or the like.

First and second gate electrodes 114a and 114b are formed on the first insulating layer 113 in regions corresponding to the first and second active layers 112a and 112b. The first gate electrode 114a is a gate electrode of the driving transistor and the second gate electrode 114b is a first electrode of the capacitor.

A second insulating layer 115 is formed on the first insulating layer 113 to cover the first and second gate electrodes 114a and 114b and to expose a portion of the first active layer 112a. The second insulating film 115 is formed of silicon oxide (SiOx), silicon nitride (SiNx), or the like.

Source / drain electrodes 116a and 116b connected to the exposed first active layer 112a are formed on the second insulating layer 115. A second electrode 116c of a capacitor is formed on the second insulating layer 114 in the same manner as the source / drain electrodes 116a and 116b and forms a capacitor together with the second gate electrode 114b.

A third insulating layer 118 is formed on the second insulating layer 115 to cover the source / drain electrodes 116a and 116b and the capacitor electrode 116c. The third insulating layer 118 is formed of silicon oxide (SiOx), silicon nitride (SiNx), or the like.

The color filter CF is formed on the third insulating layer 118. The color filter CF is a color conversion material for converting white light emitted from the organic light emitting diode unit OLED into red, green, and blue RGB.

An overcoat layer 119 is formed on the third insulating layer 118 to cover the color filter CF and expose portions of the source / drain electrodes 116a and 116b. The overcoating layer 119 may be formed of an organic material, but may be formed of an inorganic material or an organic / inorganic mixture.

The first electrode 120 connected to the exposed source / drain electrodes 116a and 116b is formed on the overcoat layer 119. The first electrode 120 is selected as an anode electrode or a cathode electrode. The first electrode 120 selected as the anode electrode may be formed of a transparent metal such as indium tin oxide (ITO) or indium zinc oxide (IZO), but is not limited thereto.

The first bank layer 121 having the first opening OPN1 exposing a part of the first electrode 120 is formed on the first electrode 120. The first bank layer 121 is formed of an inorganic material such as silicon oxide (SiOx), silicon nitride (SiNx), or the like. The first bank layer 121 has a reverse taper shape in which a region covering a portion of the first electrode 120 is drawn inward. The first bank layer 121 may have an inverse taper shape by under-cutting.

A second bank layer 122 having a second opening OPN2 exposing a part of the first bank layer 121 is formed on the first bank layer 121. The second bank layer 122 is formed of an organic material such as polyimide (PI). The second bank layer 122 occupies a narrower area than the first bank layer 121 and has a regular taper shape having a gentle inclination in a region direction exposing the first electrode 120. The thickness of the second bank layer 122 is greater than that of the first bank layer 121.

A first organic light emitting layer 123 is formed in the region 123a of the first electrode 120 and the region 123b of the second bank layer 122, and includes one light emitting material. The first organic light emitting layer 123 is divided into an area 123a of the first electrode 120 and an area 123b of the second bank layer 122 by the first bank layer 121 having an inverse taper shape. And they are in contact with each other as shown by " S "

A second organic light emitting layer 124 is formed on the first organic light emitting layer 123 to cover the first organic light emitting layer 123 and includes two light emitting materials. The first organic light emitting layer 123 is formed by being separated from each other by the first tape layer 121 having an inverse taper shape, but the second organic light emitting layer 124 is not disconnected from each other as shown by " S " It is formed in a contact state without.

The second electrode 125 is formed on the second organic light emitting layer 124 to cover the second organic light emitting layer 124. The second electrode 125 is selected as a cathode electrode or an anode electrode. The second electrode 125 selected as the cathode electrode may be formed of an opaque metal such as aluminum (Al), but is not limited thereto.

As shown in FIG. 4, the first organic light emitting layer 123 includes a first hole injection layer HIL1, a first hole transport layer HTL1, a second hole transport layer HTL2, a blue light emitting layer B_EML, and a first electron. A transport layer (ETL1) and a carrier generation layer (CGL) are included. Each layer included in the first organic light emitting layer 123 is stacked on the first electrode 120 in order. As shown in FIG. 4, the first organic light emitting layer 123 is formed in a “1Stack + CGL” structure including a carrier generation layer CGL.

The second organic light emitting layer 124 includes a second hole injection layer HIL2, a third hole transport layer HTL3, a red and green light emitting layer R + G_EML, a second electron transport layer ETL2, and an electron injection layer LiF. Included. Each layer included in the second organic light emitting layer 124 is sequentially stacked on the carrier generating layer CGL.

In the white organic light emitting display device according to the embodiment, two first and second organic light emitting layers 123 and 124 have a two stack structure, and a carrier generation layer CGL is formed between the two stacks. Formed structure.

In the white organic light emitting display device according to the embodiment, the first organic light emitting layer 123 is formed of a non-emission region by the structure of the first bank layer 121 having the reverse taper shape and the second bank layer 122 having the positive taper shape. It is formed by dividing the light emitting area. According to such a structure, the light emitting problem in the non-emission area is prevented by the carrier generating layer CGL, so that the display quality may be reduced due to the intermixing between the subpixels and the interference between the subpixels.

Hereinafter, a method of manufacturing an organic light emitting display device according to an embodiment of the present invention will be described.

5 to 8 are views for explaining a method of manufacturing an organic light emitting display device according to an embodiment of the present invention. As shown in FIGS. 5 to 8, the transistor unit TFT and the organic light emitting diode unit OLED are formed as follows.

As shown in FIG. 5, the transistor unit TFT including the color filter CF is formed on the substrate 110. The buffer layer 111 is formed on the substrate 110. The buffer layer 111 may be formed to protect the transistor unit TFT formed in a subsequent process from impurities such as alkali ions flowing out of the substrate 110, but this may be omitted. First and second active layers 112a and 112b are formed on the buffer layer 111. The first and second active layers 112a and 112b include source, channel and drain regions, and the source / drain regions are doped with P-type or N-type impurities. The first insulating layer 113 covering the first and second active layers 112a and 112b is formed on the substrate 110. The first insulating layer 113 is formed of silicon oxide (SiOx), silicon nitride (SiNx), or the like. First and second gate electrodes 114a and 114b are formed on the first insulating layer 113 in regions corresponding to the first and second active layers 112a and 112b. The first gate electrode 114a is a gate electrode of the driving transistor and the second gate electrode 114b is a first electrode of the capacitor. A second insulating layer 115 is formed on the first insulating layer 113 to cover the first and second gate electrodes 114a and 114b and to expose a portion of the first active layer 112a. The second insulating film 115 is formed of silicon oxide (SiOx), silicon nitride (SiNx), or the like. Source / drain electrodes 116a and 116b connected to the exposed first active layer 112a are formed on the second insulating layer 115. A second electrode 116c of a capacitor is formed on the second insulating layer 114 in the same manner as the source / drain electrodes 116a and 116b and forms a capacitor together with the second gate electrode 114b. A third insulating layer 118 is formed on the second insulating layer 115 to cover the source / drain electrodes 116a and 116b and the capacitor electrode 116c. The third insulating layer 118 is formed of silicon oxide (SiOx), silicon nitride (SiNx), or the like. The color filter CF is formed on the third insulating layer 118. The color filter CF is a color conversion material for converting white light emitted from the organic light emitting diode unit OLED into red, green, and blue RGB. An overcoat layer 119 is formed on the third insulating layer 118 to cover the color filter CF and expose portions of the source / drain electrodes 116a and 116b. The overcoating layer 119 may be formed of an organic material, but may be formed of an inorganic material or an organic / inorganic mixture.

As shown in FIG. 5, the first electrode 120 connected to the source / drain electrodes 116a and 116b of the driving transistor included in the transistor TFT is formed on the transistor TFT. The first electrode 120 connected to the exposed source / drain electrodes 116a and 116b is formed on the overcoat layer 119. The first electrode 120 is selected as an anode electrode or a cathode electrode. The first electrode 120 selected as the anode electrode may be formed of a transparent metal such as indium tin oxide (ITO) or indium zinc oxide (IZO), but is not limited thereto.

As shown in FIG. 5, the first bank layer 121 having the first opening OPN1 exposing a part of the first electrode 120 is formed. The first bank layer 121 having the first opening OPN1 exposing a part of the first electrode 120 is formed on the first electrode 120. The first bank layer 121 is formed of an inorganic material such as silicon oxide (SiOx), silicon nitride (SiNx), or the like. The first bank layer 121 has a reverse taper shape in which a region covering a portion of the first electrode 120 is drawn inward. The first bank layer 121 may have an inverse taper shape by etching or under-cutting using a dry etch.

As shown in FIG. 5, the second bank layer 122 having the second opening OPN2 exposing a part of the first bank layer 121 is formed. A second bank layer 122 having a second opening OPN2 exposing a part of the first bank layer 121 is formed on the first bank layer 121. The second bank layer 122 is formed of an organic material such as polyimide (PI). The second bank layer 122 occupies a narrower area than the first bank layer 121 and has a regular taper shape having a gentle inclination in a region direction exposing the first electrode 120. The thickness of the second bank layer 122 is greater than that of the first bank layer 121.

As shown in FIG. 6, the first organic light emitting layer 123 including one light emitting material is divided into the region 123a of the first electrode 120 and the region 123b of the second bank layer 122. Form. The first organic light emitting layer 123 is divided into an area 123a of the first electrode 120 and an area 123b of the second bank layer 122 by the first bank layer 121 having an inverse taper shape. And they are in contact with each other as shown in " S "

As shown in FIG. 7, a second organic light emitting layer 124 including two light emitting materials is formed to cover the first organic light emitting layer 123. The first organic light emitting layer 123 is formed to be separated from each other by the first tape layer 121 having a reverse taper shape, but the second organic light emitting layer 124 is formed in contact with each other without being interrupted by the deposited thickness.

As shown in FIG. 8, the second electrode 125 is formed to cover the second organic light emitting layer 124. The second electrode 125 is selected as a cathode electrode or an anode electrode. The second electrode 125 selected as the cathode electrode may be formed of an opaque metal such as aluminum (Al), but is not limited thereto.

In the white organic light emitting display device according to the embodiment, two first and second organic light emitting layers 123 and 124 have a two stack structure, and a carrier generation layer CGL is formed between the two stacks. Formed structure. Here, the thickness of the first organic light emitting layer 123 serving as the first stack is about 2000 kPa and the thickness of the first bank layer 121 is about 3000 kPa. The first organic light emitting layer 123 is divided into a non-light emitting area and a light emitting area by the structures of the first tape layer 121 having a reverse taper shape and the second bank layer 122 having a positive taper shape. In contrast, the second organic light emitting layer 124 and the second electrode 125 serving as the second stack are formed to be connected to all the sub pixel regions. According to such a structure, the light emitting problem in the non-emission area is prevented by the carrier generating layer CGL, so that the display quality may be reduced due to the intermixing between the subpixels and the interference between the subpixels.

As described above, the carrier generation layer CGL is formed by dividing the light emitting area and the non-light emitting area, thereby preventing the light emission problem in the non-light emitting area, and the display quality due to the interference between the subpixels as well as the occurrence of color mixing between the subpixels. There is an effect of providing a white organic light emitting display device and a method for manufacturing the same, which can solve this deterioration problem.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above may be modified in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is indicated by the following claims rather than the detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

TCN: timing controller DDRV: data driver
SDRV: Scan driver PNL: Panel
TFT: transistor portion OLED: organic light emitting diode portion
120: first electrode 121: first bank layer
122: second bank layer 123: first organic light emitting layer
124: second organic light emitting layer 125: second electrode

Claims (10)

Board;
A transistor unit formed on the substrate;
A first electrode connected to a source or drain electrode of a driving transistor included in the transistor unit;
A first bank layer having a first opening that exposes a portion of the first electrode;
A second bank layer having a second opening that exposes a portion of the first bank layer;
A first organic light emitting layer formed in a region of the first electrode and a region of the second bank layer and including one light emitting material;
A second organic light emitting layer formed to cover the first organic light emitting layer and including two light emitting materials; And
A white organic light emitting display device comprising a second electrode formed to cover the second organic light emitting layer. The method of claim 1,
The first bank layer,
A white organic light emitting display device, characterized in that the region covering a portion of the first electrode has an inverse taper shape drawn inwardly. The method of claim 1,
The second bank layer,
The white organic light emitting display device as claimed in claim 1, wherein the organic light emitting display device has a regular taper shape that occupies a narrower area than the first bank layer and has a gentle inclination toward the region exposing the first electrode. The method of claim 1,
And the first bank layer is formed of an inorganic material, and the second bank layer is formed of an organic material. The method of claim 1,
The thickness of the second bank layer is thicker than the thickness of the first bank layer, the white organic light emitting display device. The method of claim 1,
The first organic light emitting layer,
A first hole injection layer formed on the first electrode,
A first hole transport layer formed on the hole injection layer;
A second hole transport layer formed on the first hole transport layer,
A first light emitting layer formed on the second hole transport layer and including one light emitting material;
A first electron transport layer formed on the first light emitting layer,
A white organic light emitting display device comprising a carrier generating layer formed on the electron transport layer. The method of claim 6,
The second organic light emitting layer,
A second hole injection layer formed on the carrier generation layer;
A third hole transport layer formed on the second hole injection layer,
A second light emitting layer formed on the third hole transport layer and including two light emitting materials;
A second electron transport layer formed on the second light emitting layer,
A white organic light emitting display device comprising an electron injection layer formed on the second electron transport layer. Forming a transistor unit including a color filter on the substrate;
Forming a first electrode connected to a source or drain electrode of a driving transistor included in the transistor unit on the transistor unit;
Forming a first bank layer having a first opening that exposes a portion of the first electrode;
Forming a second bank layer having a second opening that exposes a portion of the first bank layer;
Forming a first organic light emitting layer including one light emitting material in a region of the first electrode and a region of the second bank layer;
Forming a second organic light emitting layer including two light emitting materials to cover the first organic light emitting layer; And
And forming a second electrode to cover the second organic light emitting layer. The method of claim 8,
The first bank layer is formed to have an inverse taper shape in which a region covering a portion of the first electrode is drawn inwardly,
And the first organic light emitting layer is formed by dividing the region of the first electrode and the region of the second bank layer by an inverse taper shape of the first bank layer. The method of claim 8,
The thickness of the second bank layer is thicker than the thickness of the first bank layer manufacturing method of a white organic light emitting display device.

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