KR100545103B1 - Organic electroluminescent device and method for manufacturing same - Google Patents

Abstract

An organic electroluminescent device and a method for manufacturing the same are disclosed. The present invention comprises the steps of preparing a transparent substrate; and forming a patterned anode electrode for each of the red, green, and blue regions on the substrate; And, red, green, organic polymer material on the anode electrode Forming a blue organic light emitting film by a spin coating method and a photolithography process; and forming a cathode electrode on the organic light emitting film, wherein the organic polymer material of red, green, and blue is subjected to a photolithography process. By forming by means of this, a process of additionally installing a color filter or a process of blending red, green, and blue organic polymer materials is unnecessary.

Description

Organic electroluminescent device and method for manufacturing same {Organic electro luminesence display and the fabrication method

1 is a cross-sectional view showing an organic EL device according to an embodiment of the present invention;

2 is a cross-sectional view showing the functional layer of FIG.

3A to 3H are cross-sectional views illustrating a state after the functional layer of FIG. 2 is formed in each step;

3A is a cross-sectional view illustrating a state in which an anode electrode is formed on a substrate of the present invention;

3B is a cross-sectional view illustrating a state in which a photoresist is formed on the substrate of FIG. 3A;

3C is a cross-sectional view showing a state of exposure on the substrate of FIG. 3B;

3D is a cross-sectional view illustrating a state in which a red region is formed on the substrate of FIG. 3C;

3E is a cross-sectional view illustrating a state in which a red organic polymer material is coated on the substrate of FIG. 3D;

3F is a cross-sectional view illustrating a state in which a photoresist is removed from the substrate of FIG. 3E;

3G is a cross-sectional view illustrating a state in which a green and blue organic polymer material is formed on a substrate of FIG. 3F;

3H is a cross-sectional view illustrating a state in which a cathode electrode is formed on the substrate of FIG. 3G.

<Description of reference numerals for main parts of the drawings>                 

10 organic electroluminescent element 11 substrate

12 ... cap 13 ... adhesive

14 ... absorbent 15 ... polarizer

100 functional layer 110 anode electrode

120 red, green, blue organic light emitting film 130 ... cathode

The present invention relates to an organic electroluminescent device, and more particularly, to fabricate red, green, and blue light emitting layers by a photolithography process so that a full color and white light emission are possible. An improved organic electroluminescent device and a method for manufacturing the same.

In general, flat display devices may be classified into light emitting type and light receiving type. The light emitting type includes a flat cathod ray tube, a plasma display panel, an organic luminescent device, a light emitting diode, and the like. The light-receiving type includes a liquid crystal display.

Among them, the organic EL device has a wide viewing angle, excellent contrast, and fast response speed, and thus has attracted attention as a next generation display device. The organic electroluminescent device is a self-luminous display device that electrically excites fluorescent organic compounds to emit light, and is capable of driving at low voltage, is easy to thin, and points out problems in liquid crystal display devices such as wide viewing angle and fast response speed. It is attracting attention as a next-generation flat panel display that can solve the problem.

The organic electroluminescent device includes an organic light emitting film made of an organic material between the anode electrode and the cathode electrode, and holes injected from the anode electrode as the anode and cathode voltages are applied to the electrodes, respectively. The electrons are moved to the organic light emitting film and the electrons are moved from the cathode electrode to the organic light emitting film, whereby electrons and holes are recombined in the organic light emitting film to generate excitons.

As the excitons change from the excited state to the ground state, the fluorescent molecules of the light emitting film emit light to form an image. In the case of a full color organic electroluminescent device, a full color is realized by providing a pixel emitting three colors of red, green, and blue.

Conventionally, a color filter was additionally used due to the problem of color reproducibility, but when the color filter is used, the cost increases, and the process also has a complicated problem. As another method, there is a so-called blending method of controlling an appropriate ratio of red, green, and blue organic materials to reproduce the organic light emitting white light, but there is still a problem that the brightness or contrast is lowered and the process is complicated. .

The present invention is to solve the above problems, the organic electroluminescent device which implements a full color and white light emitting pattern by sequentially forming a red, green, blue light emitting film formed on a substrate by a photolithography process; Its purpose is to provide a method for manufacturing the same.

In order to achieve the above object, the organic EL device according to an aspect of the present invention,

A transparent substrate;

An anode electrode patterned for each of red, green, and blue regions on the transparent substrate;

An organic light emitting layer formed on the cathode and formed for each region of red, green, and blue to form a pixel;

And a cathode electrode formed on the organic light emitting film.

The red, green, and blue organic light emitting films may be formed of an organic polymer material formed in each color by spin coating.

In addition, the red, green, and blue organic light emitting films may be separated into respective regions by a photolithography process.

An organic electroluminescent device according to another aspect of the present invention,

A transparent substrate;

An anode electrode patterned for each of red, green, and blue regions on the transparent substrate;

An organic light emitting film formed on the cathode and made of an organic polymer material formed in each color by spin coating, and formed by red, green, and blue regions to form pixels;

A cathode electrode formed on the light emitting film; And

And a cap coupled to the substrate by an adhesive to sequentially cover the stacked anode wood electrode, the organic light emitting film, and the cathode electrode to provide an organic light emitting space.

Method for manufacturing an organic electroluminescent device according to another aspect of the present invention,

Preparing a transparent substrate;

Forming an anode electrode patterned for each of red, green, and blue regions on the substrate;

Forming a red, green, and blue organic light emitting film of organic polymer material on the anode electrode by spin coating and photolithography; And

And forming a cathode electrode on the organic light emitting layer.

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

1 illustrates a conventional organic electroluminescent device 10.

Referring to the drawings, the organic electroluminescent device 10 is provided with a substrate 11. The functional layer 100 having a predetermined pattern is formed on the substrate 11. The cap 12 is provided on the functional layer 100. The cap 12 is adhesively protected by the adhesive 13. A moisture absorbent 14 is provided on the bottom of the cap 12. The polarizing plate 15 is attached to one surface of the substrate 11.

As shown in FIG. 2, the functional layer 100 includes an anode electrode 110 disposed in a stripe shape on the upper surface of the substrate 11 at a predetermined interval, and a red formed on the anode electrode 110. And a green and blue organic light emitting layer 120 and a cathode electrode 130 formed on an upper surface of the organic light emitting layer 120.

The anode electrode 110 is patterned with a reflective metal film, such as an aluminum film, for each of red, green, and blue subpixels (R, G, and B sub pixels) according to whether the top emission method or the bottom emission method is used. It consists of a dielectric transparent material having a work function of 4 eV or more, such as an ITO transparent electrode. In addition, when the anode electrode 110 is formed of a reflective metal film, a double layer structure in which a conductive film made of an ITO film having a thinner thickness may be additionally coated.

The red, green, and blue organic light emitting films 120 are patterned on the anode electrode 110 independently of each other, and the red light emitting film R made of an organic polymer material is MEH-PPV. (poly [2-Methoxy-5-(2 '-ethylhexyloxy)-1, 4-phenylenevinylene], the green light emitting film (G) is CN-PF6V (Poly 9, 9-dihexyl-2, 7 (2-cyanovinylene ) fluoreneylene), and the blue light emitting film (B) preferably uses PFO (poly 9, 9-dioctylfluorene-2, 7-diyl).

The cathode electrode 130 may be formed as a common layer with respect to the red, green, and blue organic light emitting layers 120, and may be patterned in a direction orthogonal to the anode electrode 110. . The cathode electrode 130 is formed of a semi-transmissive metal film, such as a magnesium (Mg) film, a silver (Ag) film, or a mixed film of magnesium-silver. A protective film made of a transmissive conductive oxide, such as an ITO (indium tin compound) film or an IZO (indium zinc oxide) film, may be further deposited on the top surface of the cathode electrode 130.

The manufacturing process of the organic EL device 10 having the above structure will be briefly described as follows.

First, a substrate 11 made of transparent glass is prepared, and then the anode electrode, organic light emitting film, and cathode electrode of the functional layer 100 are patterned on the substrate 11, and then the adhesive 13 is used. The cap 14 made of metal is mounted, and the polarizing plate 15 is attached to one surface of the substrate 11. At this time, the bottom surface of the cap 13 is provided with a moisture absorbent 14 to remove moisture from the inner space of the sealed element.

Here, the manufacturing process of the functional layer 100 according to the features of the present invention will be described with reference to FIGS. 3A to 3H.

First, a substrate 11 made of transparent glass is provided. On the right side of the substrate 11, the anode metal 110 made of a reflective metal film such as an aluminum film or a transparent conductive film is patterned for red, green, and blue. The anode electrode 110 is formed by a deposition method. After the anode electrode 110 is formed, water, isopropyl alcohol and acetone are cleaned using an ultraviolet cleaner (FIG. 3A).                     

Subsequently, the anode electrode 110 is buried by the photoresist 31. The photoresist 31 is coated on the substrate 11 to completely cover the anode electrode 110 by spin coating. The thickness of the photoresist 31 should be relatively thicker than the thickness of the red, green, and blue organic light emitting film 120 to be formed later (Fig. 3b).

Subsequently, after the UV curing treatment on the substrate 11, a soft bake is performed for about 5 minutes at a temperature of about 80 ° C. to remove the solvent contained in the photoresist 31. .

After the solvent is removed, the photomask 32 is provided at a position spaced apart from the upper portion of the substrate 11 by a predetermined interval, and the exposure and development are performed to form a region in which the red light emitting layer is to be formed (FIG. 3C).

After exposing and developing only to a region where a red light emitting layer is to be formed, the photoresist 31 in the red region is removed to expose the anode electrode 110. In this case, a hard bake is performed for about 30 minutes at a temperature of about 120 ° C. for stabilization and position fixing of the photoresist 31. (FIG. 3D)

Next, the red light emitting layer 120R is formed by spin coating MEH-PPV on the red region. At this time, the solvent is dried at room temperature in order to remove the solvent remaining in the red light emitting film 120R.

Subsequently, the photoresist 31 used until the red light emitting layer 120R is formed is removed using an organic solvent such as acetone. As a result, a red light emitting film 120R is formed (FIG. 3F).

Next, the green light emitting film 120G and the blue light emitting film 120B are spin-coated by CN-PF6V in the green area and PFO in the blue area by the same method as the process of forming the red light emitting film 120R. ) Will be formed sequentially. (FIG. 3G)

After forming the red, green, and blue light emitting films 120R, 120G, and 120B by spin coating, the cathode electrode 130 is formed on the upper surface thereof. The cathode electrode 130 is thermally deposited using magnesium and silver to form a semi-permeable electrode. In this case, unlike the anode electrode 110, the cathode electrode 130 is to be formed as a common electrode for the convenience of the process will be preferred. On the other hand, the upper surface of the cathode electrode 130 may be further formed a protective film of a transparent conductive oxide (Fig. 3h).

Subsequently, the cap 12 equipped with the moisture absorbent 14 is sealed to the substrate 11 using a glass and an ultraviolet adhesive 13 (see FIG. 1) under a nitrogen gas atmosphere or anhydrous conditions. The organic electroluminescent device 10 can be completed by heat curing treatment.

The operation of the organic EL device 10 having the above structure will be briefly described as follows.

When a voltage is applied between the anode electrode 110 and the cathode electrode 130, holes injected from the selected anode electrode 110 are red, green, and blue organic light emitting layers 120 made of an organic polymer material. Is moved to). On the other hand, electrons are injected into the organic emission film 120 from the cathode electrode 130. Carriers are recombined in the organic emission layer 120 to generate excitons. The excitons change from the excited state to the ground state, whereby the fluorescent molecules of the organic light emitting film 120 of red, green, and blue are generated to reproduce the image.

As described above, the organic electroluminescent device of the present invention and a method for manufacturing the same can obtain the following effects.

First, by forming a red, green, and blue organic polymer material by a photolithography process, a process of additionally installing a color filter or a process of blending the red, green and blue organic polymer materials is unnecessary.

Second, the manufacturing process is simplified by forming a red, green, and blue organic light emitting film by simple repetition by a photolithography process.

Third, as the manufacturing process is simplified, the manufacturing cost is reduced.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Could be. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (8)

A transparent substrate; An anode electrode patterned for each of red, green, and blue regions on the transparent substrate; An organic light emitting layer formed on the anode electrode and formed for each of red, green, and blue regions to form a pixel; And a cathode electrode formed on the organic light emitting film. The red, green, and blue organic light emitting film is an organic electroluminescent device, characterized in that made of an organic polymer material formed in each color by a spin coating method. The method of claim 1, The organic light emitting diodes of red, green, and blue are separated into respective regions by a photolithography process. A transparent substrate; An anode electrode patterned for each of red, green, and blue regions on the transparent substrate; An organic light emitting film formed on the anode electrode and formed of an organic polymer material formed in each color by spin coating, and formed by red, green, and blue regions to form pixels; A cathode electrode formed on the light emitting film; And And a cap coupled to the substrate by an adhesive to sequentially cover the stacked anode wood electrode, organic light emitting film, and cathode electrode to provide an organic light emitting space. The method of claim 3, wherein The organic light emitting diodes of red, green, and blue are separated into respective regions by a photolithography process. Preparing a transparent substrate; Forming an anode electrode patterned for each of red, green, and blue regions on the substrate; Forming a red, green, and blue organic light emitting film of organic polymer material on the anode electrode by spin coating and photolithography; And Forming a cathode on the organic light emitting film; a method of manufacturing an organic electroluminescent device, comprising: a. The method of claim 5, In the step of forming the organic light emitting film by a spin coating method and a photolithography process, Coating a photo resistor on the anode electrode; Exposing and developing red, green, and blue regions to form the photoresist to form regions of a specific color; Coating an organic polymer material having a corresponding color on the formed region by spin coating to form an organic light emitting film; Removing the photoresist; the manufacturing method of the organic electroluminescent device comprising a. The method of claim 6, The thickness of the photoresist is a method of manufacturing an organic electroluminescent device, characterized in that formed thicker than the thickness of the organic light emitting film of red, green, blue. The method of claim 5, In the forming of the polymer organic light emitting film, Red, green, and blue organic light emitting films are formed in the corresponding areas by spin coating and photolithography for each color, and then sequentially formed in different color areas by the same method. Manufacturing method.

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