KR20150015139A - Organic Light Emitting Diode Display Device and Method of manufacturing the same - Google Patents

Abstract

The present invention relates to an organic light emitting diode display device and a method of manufacturing the same. The organic light emitting diode display device includes: a substrate where a light emitting region and a non-light emitting region forming a periphery of the light emitting region are defined; a first electrode formed on the light emitting region of the substrate; a partition formed on the non-light emitting region of the substrate; a hole layer formed on the partition and the entire surface of the first electrode; a light-emitting layer formed on a light emitting region on the hole layer; and a second electrode formed on the light emitting layer. The surface of the hole layer is divided into a hydrophilic region and a hydrophobic region. There is no need to apply a special partition material representing a hydrophobic property to an ink composition. Stain due to non-diffusion failure and coffee ring effect of the ink composition may be improved.

Description

[0001] The present invention relates to an organic light emitting display device and a method of manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device using an inkjet printing method and a method of manufacturing the same.

In recent years, the importance of display devices has been increasing with the development of multimedia. In response to this, flat panel display devices such as a liquid crystal display device, a plasma display device, and an organic light emitting display device have been commercialized. Among the flat panel display devices, the organic light emitting display device is a self-luminous display device that emits light by itself, has a high response speed, and has a large luminous efficiency, luminance, and viewing angle. Thus, the OLED display device can be used for a notebook computer, a television, a tablet computer, , Portable information devices, and the like.

Hereinafter, a conventional organic light emitting display device will be described with reference to the drawings.

FIG. 1 is a diagram illustrating a band diagram of a general organic light emitting display device. Referring to FIG.

1, a general organic light emitting display device includes a hole injection layer (anode) 1, a cathode electrode 2, and a hole injection layer (anode) 2 formed between the anode electrode 1 and the cathode electrode 2, a hole transport layer (HTL) 4, an emission layer (EML) 5, an electron transporting layer (ETL) 6, an electron injection layer electron injection layer (EIL) (7). In this organic light emitting display device, when a voltage is applied between the anode 1 and the cathode 2, holes injected into the light emitting layer 5 through the hole injecting layer 3 and the hole transporting layer 4, Electrons injected into the light emitting layer 5 through the electron injecting layer 7 and the electron transporting layer 6 are combined in the light emitting layer 5 to generate excitons and the excitons are excited in the base state And emits light.

The organic light emitting display device may be driven by a passive matrix method without a separate thin film transistor and an active matrix method using a thin film transistor for each pixel active matrix) method. In recent years, active matrix organic light emitting display devices for display manufacturing requiring a high resolution or a large screen have been studied and developed due to limitations in resolution, power consumption, and life span of the passive matrix method.

In forming an organic light emitting layer of such an active matrix organic light emitting display device, an inkjet printing method which is simple in process and low in manufacturing cost has been attracting attention.

The ink-jet printing method is to form red, green and blue pixels by ejecting the light-emitting material from a head of an ink-jet printing apparatus after dissolving or dispersing the light-emitting material in a solvent.

FIG. 2 is a view showing an ink-jet printing method for forming an organic light emitting layer of a conventional active matrix organic light emitting display device, and FIG. 3 is a view for explaining a problem of a conventional active matrix organic light emitting display device.

Referring to FIG. 2, an ink-jet printing method for forming an organic light emitting layer in a conventional active matrix organic light emitting display device includes a first electrode 20 formed on a light emitting region on a substrate 10, (30) is formed in the non-emission region on the substrate (10). A hole-related layer 40 is formed between the barrier ribs 30. The hole-related layer 40 may be a single layer of the hole transport layer 43, or may be a multi-layer of the hole injection layer 41 and the hole transport layer 43.

Next, an ink composition 70 for a light emitting layer of red (R), green (G), and blue (B) is applied between the partition walls 30 on the hole-related layer 40 to the head 61 of the ink- And then the light emitting layer 50 is formed by heating, light irradiation, or the like. At this time, since the ink composition 70 has a hydrophilic property, the barrier rib 30 is formed of a hydrophobic material. That is, if both the ink composition 70 and the partition wall 30 are hydrophilic, there is a problem that the ink composition 70 for the light emitting layer forming the light emitting layer 50 can not be prevented from being dispersed to adjacent pixels , The partition wall 30 should have hydrophobicity if the ink composition 70 has hydrophilicity.

However, as shown in FIG. 3, the conventional active matrix organic light emitting display device has the following problems.

Due to the difference in surface characteristics between the hydrophilic ink composition 70 and the hydrophobic barrier 30, the ink composition does not spread well to the portion contacting the ink composition 70, There is a problem in that the coffee ring effect is large due to the uneven surface between the center portion and the center portion, resulting in unevenness.

Disclosure of the Invention The present invention has been conceived to solve the above-mentioned conventional problems, and it is an object of the present invention to provide an organic light emitting display device and a method of manufacturing the same, which can improve uneven spreading of ink composition and stain caused by a coffee ring effect And to provide a method of manufacturing the same.

Other features and advantages of the invention will be set forth in the description which follows, or may be obvious to those skilled in the art from the description and the claims.

According to an aspect of the present invention, there is provided an organic light emitting display device including a substrate defining a light emitting region and a non-emitting region that forms a peripheral portion of the light emitting region, a first electrode formed on the light emitting region on the substrate, A hole-related layer formed on the front surface of the first electrode, a light-emitting layer formed on the light-emitting region on the hole-related layer, and a second electrode formed on the light-emitting layer, the surface of the hole- Is divided into a hydrophilic region and a hydrophobic region.

According to another aspect of the present invention, there is provided a method of manufacturing an organic light emitting display device, comprising: forming a first electrode on a substrate defining a light emitting region and a non-emitting region forming a peripheral portion of the light emitting region; Forming a hole-related layer on the entire surface of the partition and the first electrode; separating the surface of the hole-related layer into a hydrophilic region and a hydrophobic region to perform a surface treatment; And forming a second electrode on the light emitting layer.

According to the solution of the above-mentioned problems, the present invention has the following effects.

In the present invention, since the surface of the hole-related layer is selectively divided into a hydrophilic region and a hydrophobic region, the exposed hydrophobic region exhibits hydrophobicity in the ink composition and the non-exposed region exhibits hydrophilicity in the ink composition without changing surface characteristics, The ink composition can be spread well at the portion contacting with the composition, and the problem that the uneven spreading of the resulting ink composition and the stain caused by the coffee ring effect can be solved.

Second, the present invention selectively separates the surface of the hole-related layer into a hydrophilic region and a hydrophobic region by ultraviolet rays without applying a special hydrophobic material to the partition wall, thereby preventing the ink composition from being dispersed to adjacent pixels Thus simplifying the process and developing the technology.

Thirdly, since the width of the hydrophobic region of the hole-related layer can be selectively controlled, the width of the barrier can be relatively reduced and the resolution can be improved.

FIG. 1 is a diagram illustrating a band diagram of a general organic light emitting display device. Referring to FIG.
2 is a view illustrating an ink-jet printing method for forming an organic light emitting layer of a conventional active matrix organic light emitting display device.
3 is a view for explaining a problem of a conventional active matrix organic light emitting display device.
4 is a schematic cross-sectional view illustrating an organic light emitting display device according to an embodiment of the present invention.
5 is a comparative view for explaining surface characteristics of the hole-related layer of the organic light emitting display device according to the present invention.
6 is a schematic cross-sectional view illustrating another embodiment of forming a hole-related layer in the organic light emitting display device according to the present invention.
7 is a schematic cross-sectional view illustrating another embodiment of forming the light emitting layer of the organic light emitting display device according to the present invention.
8A to 8F are schematic manufacturing cross-sectional views of an organic light emitting display device according to the present invention.
9A to 9C are cross-sectional views illustrating a method of surface-treating a hole-related layer of an organic light emitting display device according to the present invention.

The meaning of the terms described herein should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms.

It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one.

The term "on" means not only when a configuration is formed directly on top of another configuration, but also when a third configuration is interposed between these configurations.

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

FIG. 4 is a schematic cross-sectional view illustrating one embodiment of the organic light emitting display device according to the present invention, and FIG. 5 is a comparative view for explaining surface characteristics of the hole related layer of the organic light emitting display device according to the present invention.

Referring to FIG. 4, the OLED display includes a substrate 100, a first electrode 200, a barrier 300, a hole-related layer 400, a light-emitting layer 500, and a second electrode 600 ).

The first electrode 200 is formed in a light emitting region on the substrate 100. The substrate 100 may be a transparent substrate, glass, plastic, or a quartz substrate.

The first electrode 200 may be an anode electrode or a cathode electrode forming the lower electrode. When the first electrode 200 is an anode, a second electrode 600 described later becomes a cathode, and when the first electrode 200 is a cathode, a second electrode 600 described later becomes an anode. If the first electrode 200 is a cathode, the first electrode 200 may be made of Mg, Ca, Al, Ag, Ba, or an alloy thereof so as to be thin enough to allow light to pass therethrough. In the case of the anode, ITO or IZO .

The barrier ribs 300 are formed in the non-emission region on the substrate 100.

The partition 300 separates each pixel. That is, the barrier rib 300 prevents the ink composition for the light emitting layer forming the light emitting layer 500 from being dispersed to adjacent pixels. For this, the barrier ribs 300 are formed with a predetermined width and height.

The hole-related layer 400 is formed on the entire surface of the barrier rib 300 and the first electrode 200. The hole-related layer 400 may be a single layer of the hole transport layer 430 or may be a multilayer of the hole injection layer 410 and the hole transport layer 430.

The hole injection layer 410 is patterned in a light emitting region on the first electrode 200. The hole injection layer 410 allows holes to enter the light emitting layer 500 from the first electrode 200.

The hole transport layer 430 is formed on the entire surface of the barrier rib 300 and the first electrode 200. The hole transport layer 430 transports holes injected from the first electrode 200 or the hole injection layer 410 to the light emitting layer 500.

In general, the hole-related layer 400 is formed to be thicker than the other layers in order to reduce the influence of pin-holes and peaks of the anode electrode.

At this time, the surface of the hole-related layer 400 is made of a material capable of selectively separating the hydrophilic region 402 and the hydrophobic region 401 by ultraviolet rays (UV).

For this purpose, the hole-related layer 400 may include any one of isopropyl alcohol, propylene glycol mono methyl ether, and diethylene glycol methyl ethyl ether. . In addition, although not illustrated, the surface of the hole-related layer 400 may be made of a material which is excellent in dispersion characteristics of a hydrophobic component in addition to the above-mentioned material and can change hydrophilic to hydrophobic by ultraviolet rays (UV).

That is, the surface of the hole-related layer 400 is hydrophilic. The portion exposed to ultraviolet rays by using a mask (not shown) is changed from hydrophilic to hydrophobic to become the hydrophobic region 401, Becomes a hydrophilic region 402. [

5 is a comparative view for explaining surface characteristics of the hole-related layer of the organic light emitting display device according to the present invention.

FIG. 5 is a graph showing the surface of a hole-related layer comprising any one of isopropyl alcohol, propylene glycol mono methyl ether, and diethylene glycol methyl ethyl ether. It shows whether the surface properties are changed by ultraviolet (UV).

Referring to FIG. 5, the contact angle of the surface of the hole-related layer is increased by 55 degrees from 5 degrees before and after exposure by ultraviolet (UV) illumination (23.7 mW / cm2). Therefore, when the surface of the hole-related layer made of any one of isopropyl alcohol, propylene glycol mono methyl ether and diethylene glycol methyl ethyl ether is ultraviolet (UV) The hydrophilic property changes from hydrophilic to hydrophobic.

Conventionally, in order to prevent the ink composition for the light emitting layer containing the organic material from being dispersed to adjacent pixels, the barrier rib 300 is formed by applying a special material having hydrophobicity to the ink composition for the light emitting layer, Respectively.

However, according to the present invention, by changing the surface characteristics of the hole-related layer 400 by ultraviolet (UV), the partition wall 300 can be formed with an ink composition for an emitting layer containing an organic material without using a special hydrophobic material It can be prevented from being dispersed to adjacent pixels.

Therefore, it is not necessary to form a partition wall using a special material having hydrophobicity in the ink composition, thereby simplifying the process and developing the technology.

Referring again to FIG. 4, the light emitting layer 500 is formed in the light emitting region on the hole related layer 400.

The light emitting layer 500 generates excitons by combining holes and electrons and emits light when the excitons transit from the excited state to the ground state.

The light emitting layer 500 is formed of an ink composition for an organic light emitting layer including red (R), green (G), and blue (B).

The light emitting layer 500 of the organic light emitting display device is formed as a light emitting layer corresponding to each of red (R), green (G), and blue (B) in the light emitting region on the hole- do.

The light emitting layer 500 is patterned by an inkjet printing method. The ink composition is made of a hydrophilic soluble material.

The second electrode 600 is formed on the entire surface of the substrate 100 including the light emitting layer 500.

The second electrode 600 may be an anode electrode or a cathode electrode forming the upper electrode. The second electrode 600 is formed as a cathode when the first electrode 200 is an anode and is formed as an anode when the first electrode 200 is a cathode. If the second electrode 600 is a cathode, the second electrode 600 may be formed to a thickness thin enough to transmit light by using Mg, Ca, Al, Ag, Ba, or an alloy thereof. In the case of the anode, ITO or IZO .

Hereinafter, repetitive description of the repetitive portions in the materials, structures and the like of each constitution will be omitted.

6 is a schematic cross-sectional view illustrating another embodiment of forming a hole-related layer in the organic light emitting display device according to the present invention. The hole-related layer 400 includes a hole injection layer 410 and a hole transport layer 430 Is the same as the organic light emitting display device of FIG. 4 except that the structure of FIG. 4 is changed. Therefore, the same reference numerals are assigned to the same components, and repetitive description of the same components will be omitted.

As shown in FIG. 6, the hole-related layer 400 includes a hole injection layer 410 and a hole transport layer 430.

The hole injection layer 410 is formed on the entire surface of the barrier 300 and the first electrode 200 and the hole transport layer 430 is formed on the entire surface of the hole injection layer 410.

7 is a schematic cross-sectional view illustrating another embodiment of forming a light emitting layer of the organic light emitting display device according to the present invention. The organic light emitting display device and the organic light emitting display device of FIG. 4, except that the structure of the light emitting layer 500 is changed, same.

Referring to FIG. 7, the light emitting layer 500 of the organic light emitting display device includes a red (R) emitting layer, a green (G) emitting layer, and a blue (B) emitting layer.

A red (R) light emitting layer 510 and a green (G) light emitting layer 520 are formed in a light emitting region on the hole-related layer 400. The red (R) Emitting layer 530 is formed on the entire surface of the hole-related layer 400 including the light-emitting layer 520.

In this case, since the red (R) and green (G) light emitting layers are formed by the inkjet printing method and the blue (B) light emitting layer has a significantly shorter life than the red (R) .

At this time, the blue (B) light emitting layer may be formed by a vacuum deposition method, and although not shown, the same material as the electron transporting layer (ETL) or the electron injection layer (EIL) . For example, an aluminum quinolynol complex.

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

8A to 8F are schematic manufacturing cross-sectional views of an organic light emitting display device according to the present invention.

Referring to FIG. 8A, a first electrode 200 is formed in a light emitting region on a substrate 100. Next, a barrier rib 300 is formed in a non-emission region on the substrate 100. The barrier ribs 300 are formed in a non-emission region by patterning by a mask process.

Referring to FIG. 8B, a hole-related layer 400 is formed on the entire surface of the barrier rib 300 and the first electrode 200.

The hole-related layer 400 may be formed by spin coating, slit coating, or the like.

At this time, the hole-related layer 400 may include isopropyl alcohol, propylene glycol mono methyl ether, diethylene glycol methyl ether, and the like, which are easily dispersed in a hydrophobic component by an ultraviolet ray reaction. Ethyl ether (diethylene glycol methyl ethyl ether).

Referring to FIG. 8C, the surface of the hole-related layer 400 is divided into a hydrophilic region 402 and a hydrophobic region 401.

The surface treatment of the hole-related layer 400 changes the surface of the non-emission region of the hole-related layer 400 from hydrophilic to hydrophobic by ultraviolet exposure.

In other words, by irradiating ultraviolet rays to the hole-related layer 400 while masking a portion corresponding to the light-emitting region of the hole-related layer 400 using the mask 700, the hole-related layer 400 Is a hydrophobic region 401 changed from hydrophilic to hydrophobic, and the surface of the hole-related layer 400 not exposed to ultraviolet rays becomes a hydrophilic region 402. [

Referring to FIGS. 8D and 8E, a light emitting layer 500 is formed in a light emitting region on the hole-related layer 400. FIG.

8D, a red (R) light emitting layer 510 and a green (G) light emitting layer 520 are patterned by an ink-jet printing method on a light emitting region on the hole related layer 400. As shown in FIG.

More specifically, the red (R) and green (G) ink compositions 71 and 72 for the light emitting layer are sandwiched between the partition walls 300 on the hole-related layer 400 from the head 61 of the inkjet printing apparatus 60 And then red (R) light emitting layer 510 and green (G) light emitting layer 520 are formed by co-sputtering by heating or light irradiation.

The ink composition may be a hydrophilic soluble fluorescent material, an organic compound that is a copolymer of polyparaphenylenevinylene and derivatives thereof, or a copolymer having at least one of them.

8E, the blue (B) light emitting layer 530 is formed on the entire surface of the hole related layer 400 including the red (R) light emitting layer 510 and the green (G) light emitting layer 520 And is formed by a deposition method.

At this time, the blue (B) light emitting layer may be formed of a fluorescent material by a vacuum deposition method, and a material similar to an electron transporting layer (ETL) or an electron injection layer (EIL) Is preferably used. For example, an aluminum quinolynol complex.

Next, referring to FIG. 8F, a second electrode 600 is formed on the light emitting layer 500.

The second electrode 600 is formed on the entire surface of the substrate 100 including the light emitting layer 500.

Hereinafter, the repeated description of the respective components and the ultraviolet surface treatment method and the like will not be repeated.

9A to 9C are cross-sectional views illustrating a method of surface-treating a hole-related layer of an organic light emitting display device according to the present invention, wherein a surface of the hole-related layer 400 is divided into a hydrophilic region 402 and a hydrophobic region 401 8A to 8F are the same as the method of manufacturing the organic light emitting display device described above. Therefore, the same reference numerals are assigned to the same components, and repetitive description of the same components will be omitted.

9A to 9C, the width of the hydrophobic region 401 of the hole-related layer 400 is determined by the length of the mask 700 used for ultraviolet exposure, and the width of the hydrophobic region 401 of the hole- Can be selectively controlled by adjusting the amount.

That is, when the length of the mask 700 is increased and ultraviolet rays are irradiated, the hydrophobic region 401 of the hole-related layer 400 is narrowed. When the length of the mask 700 is shortened and ultraviolet rays are irradiated, The hydrophobic region 41 of the hole-related layer 400 is widened.

As a result, since the width of the hydrophobic region 401 of the hole-related layer 400 can be selectively controlled, the width of the barrier rib 300 can be relatively reduced, thereby improving the resolution.

100: substrate 200: first electrode
300: barrier rib 400: hole-related layer
410: Hole injection layer 420: Hole transport layer
500: light emitting layer 600: second electrode

Claims (10)

Emitting region and a peripheral region of the light-emitting region;
A first electrode formed on a light emitting region on the substrate;
A barrier rib formed in the non-emission region on the substrate;
A hole related layer formed on the front surface of the partition and the first electrode;
A light-emitting layer formed in the light-emitting region on the hole-related layer; And
And a second electrode formed on the light emitting layer,
And the surface of the hole-related layer is divided into a hydrophilic region and a hydrophobic region. The method according to claim 1,
The hole-related layer may include any one of isopropyl alcohol, propylene glycol mono methyl ether, and diethylene glycol methyl ethyl ether. Gt; organic light emitting display device. The method according to claim 1,
Wherein the light emitting layer comprises a red light emitting layer, a green light emitting layer, and a blue light emitting layer,
Wherein the red light emitting layer and the green light emitting layer are formed adjacent to the light emitting region between the partition walls,
Wherein the blue light emitting layer is further formed on the entire surface of the hole related layer including the red light emitting layer and the green light emitting layer. The method of claim 3,
Wherein the red light emitting layer and the green light emitting layer are phosphorescent materials, and the blue light emitting layer is a fluorescent material. Forming a first electrode on a substrate on which a non-emission region that is a peripheral portion of the emission region and the emission region is defined;
Forming a barrier rib in the non-emission region on the substrate;
Forming a hole-related layer on the entire surface of the partition and the first electrode;
Separating the surface of the hole-related layer into a hydrophilic region and a hydrophobic region;
Forming a light emitting layer in a light emitting region on the hole related layer; And
And forming a second electrode on the light emitting layer. 6. The method of claim 5,
Wherein the surface treatment of the hole-related layer changes the surface of the non-emission region of the hole-related layer from hydrophilic to hydrophobic by ultraviolet exposure. 6. The method of claim 5,
And the width of the hydrophobic region of the hole-related layer is selectively controlled according to the length of the mask used for ultraviolet exposure. 6. The method of claim 5,
The hole-related layer may include any one of isopropyl alcohol, propylene glycol mono methyl ether, and diethylene glycol methyl ethyl ether. Gt; to < / RTI > 6. The method of claim 5,
The forming of the light emitting layer may include:
Forming a red light emitting layer and a green light emitting layer in the light emitting region between the barrier ribs;
And forming a blue light emitting layer on the entire surface of the hole related layer including the red light emitting layer and the green light emitting layer. 10. The method of claim 9,
Wherein the red light emitting layer and the green light emitting layer are formed by an inkjet printing method,
Wherein the blue light emitting layer is formed by a deposition method.

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