JP2004006091A - Manufacturing method for organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a high accuracy organic electroluminescent element without color mixture. <P>SOLUTION: A transparent substrate 4 has the first electrodes 5, a hole transporting layer 6, and a light-emitting layer 7 which are formed sequentially on its surface. A stamp substrate 1 has recesses 2 on its surface. The recesses 2 of the stamp substrate 1 are filled up with phosphor coloring matter 3. The transparent substrate 4 and the stamp substrate 1 are disposed with close contact in such a way that the light-emitting layer 7 and the recesses 2 face each other, and the assembly is heated in order to diffuse the phosphor coloring matter 3 in the recesses 2 into the light-emitting layer 7. The stamp substrate 1 is estranged from the transparent substrate 4, and the second electrodes 11 are formed on the light-emitting layer 7 of the transparent substrate 4. The recesses 2 of the stamp substrate 1 is filled with the phosphor coloring matter 3 by the ink jet method using solution which is made by melting the phosphor coloring matter 3 in organic solvent. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing an organic electroluminescence device (organic EL device).
[0002]
[Prior art]
Organic EL devices have high response speed and emit light with no viewing angle dependence with low power consumption, and are being considered for application to display devices such as portable terminals and personal computers as display devices. Therefore, it has been put to practical use as an area color display element in which a mono color is partially combined in an in-vehicle audio display panel.
[0003]
When a display element corresponding to red (R), green (G), and blue (B) is combined, a full-color display can be performed. Various studies have been made.
[0004]
The method of manufacturing the organic EL device is disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 7-235378 and Applied Physics Letters Vol. 74, No. 13, 1913-1915, 1999.
That is, in Japanese Patent Application Laid-Open No. Hei 7-235378, a transparent substrate on which a stripe-shaped transparent electrode serving as an anode is formed in advance is prepared, and a hole transport layer is formed on the transparent electrode by a wet method such as spin coating or an evaporation method. Forming, applying a red fluorescent dye, a green fluorescent dye, and a blue fluorescent dye on the hole transport layer by a screen printing method or an ink-jet method so as to be separated from each other. Irradiating infrared light from the substrate to diffuse the fluorescent dye of each color into the hole transport layer to form a red light emitting portion, a green light emitting portion, and a light emitting layer including a blue light emitting portion in the hole transport layer; and A hole transport layer and a material of a fluorescent dye, comprising a step of laminating an electron transport layer thereon, and a step of forming a metal electrode which is orthogonal to the transparent electrode and serves as a cathode on the electron transport layer. Constrained by any ones can be selected without, and lithography in the formation of the light-emitting layer, a method of manufacturing an organic EL element is disclosed patterned screen printing or the like is not required.
[0005]
In Applied Physics Letters Vol. 74, No. 13, 1913-1915, 1999, a hole transport layer is formed on a transparent substrate having a transparent electrode, and the transparent substrate and another substrate on which the dye layer is formed are covered with a shadow mask. A method of manufacturing an organic EL device in which a light emitting layer is formed by sublimating and diffusing from the dye layer to the hole transport layer side after interposing and opposing each other is disclosed.
[0006]
However, in the former case, when applying each color fluorescent dye on the hole transport layer by a screen printing method or an ink jet method, it is necessary to form a bank in a portion other than the ink discharge port in order to accurately perform ink discharge positioning. And it was difficult to achieve high definition.
Also, in the latter case, it is difficult to reduce the size of the shadow mask.
[0007]
Therefore, a method of manufacturing an organic EL device capable of achieving high definition as shown in FIG. 2 has been proposed. 2A and 2B are cross-sectional views illustrating a conventional method for manufacturing an organic EL element. FIG. 2A illustrates a (first step), FIG. 2B illustrates a (second step), and FIG. (D) shows (Fourth step), (E) shows (Fifth step), (F) shows (Sixth step), (G) Indicates (seventh step).
[0008]
(First step)
As shown in FIG. 2A, after a photoresist is applied on a stamp substrate 1 made of Si, a photoresist pattern 9 is formed using a photomask (not shown).
[0009]
(2nd process)
Thereafter, as shown in FIG. 2B, the recess 2 is formed in the stamp substrate 1 by etching by reactive ion etching (RIE), and then the photoresist pattern 9 is removed. The etching gas used in this RIE is CHF ₃ or the like.
[0010]
(3rd step)
Next, as shown in FIG. 2C, a red fluorescent dye 3 is deposited on the stamp substrate 1 by a vacuum deposition method. Here, the fluorescent dye 3 is a red fluorescent dye.
[0011]
(4th process)
Next, as shown in FIG. 2 (D), after sticking an adhesive tape 10 on the surface of the stamp substrate 1 on which the fluorescent dye 3 is formed, the fluorescent dye 3 deposited on the surface of the stamp substrate 1 is peeled off. Then, the fluorescent dye 3 is left only in the concave portion 2.
[0012]
(Fifth step)
Next, as shown in FIG. 2E, a transparent substrate 4 having a stripe-shaped transparent electrode 5 different from the stamp substrate 1 is prepared, and a hole transport layer 6 and a light emitting layer 7 are formed. Here, the transparent substrate 4 is glass.
[0013]
(Sixth step)
Next, as shown in FIG. 2 (F), heating is performed in a state where the concave portion 2 side of the stamp substrate 1 and the light emitting layer 7 side of the transparent substrate 4 are closely arranged to face each other, and the red fluorescent dye deposited on the concave portion 2 is formed. 3 is diffused into the light emitting layer 7. Thus, the red light emitting layer 8 is formed in the light emitting layer 7. Thereafter, the stamp substrate 1 is separated from the transparent substrate 4.
Further, the same operation as described above is performed for the green fluorescent dye and the blue fluorescent dye to form the fluorescent emission layer 8 of these dyes.
At this time, each of the red fluorescent dye, the green fluorescent dye, and the blue fluorescent dye is formed in a predetermined pattern, for example, a staggered pattern or a vertical stripe pattern, and is formed without overlapping each other.
[0014]
(Seventh step)
Thereafter, as shown in FIG. 2G, a metal electrode 11 orthogonal to the transparent electrode 5 is formed on the light emitting layer 7 to manufacture an organic EL device. This organic EL element can obtain color light emission from the light emitting layer 7 by applying a voltage between the transparent electrode 5 as an anode and the metal electrode 11 as a cathode, for example.
In addition, by using the same material as the transparent substrate for the stamp substrate, it is possible to prevent a pixel pitch due to a difference in thermal expansion coefficient during heating. The fluorescent dye 3 is made of a phosphorescent material.
[0015]
[Problems to be solved by the invention]
However, in the (fourth step), after the adhesive tape 10 is attached to the surface of the stamp substrate 1 on which the fluorescent dye 3 is formed, the adhesive tape 10 is peeled off, and the fluorescent dye 3 on the surface of the stamp substrate 1 is removed. In this case, a part of the adhesive material of the adhesive tape 10 may adhere to the stamp substrate 1 and the fluorescent dye 3 may not be removed.
[0016]
This means that, in (sixth step), when each color fluorescent dye is diffused into the light emitting layer 7 of the transparent substrate 4, the fluorescent dye 3 is also diffused into the light emitting layer 7 other than the diffused region. When the green and blue fluorescent dyes are diffused, color mixing occurs. In order to prevent this, another process of removing the adhesive tape 10 stuck to the surface of the stamp substrate 1 is required, which has caused a problem that the manufacturing process is complicated.
[0017]
Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method of manufacturing an organic EL device capable of achieving high definition without causing color mixing.
[0018]
[Means for Solving the Problems]
According to the present invention, a transparent substrate having a first electrode, a hole transport layer, and a light emitting layer formed on a surface thereof in advance and a stamp substrate having a concave portion formed on the surface are prepared. After filling the fluorescent dye, then the light emitting layer and the concave portion are arranged to face each other, and the transparent substrate and the stamp substrate are placed in close contact with each other, and then heated to apply the fluorescent dye in the concave portion to the light emitting layer. Diffusion, then, after separating the stamp substrate from the transparent substrate, a method of manufacturing an organic electroluminescent element, which is manufactured by forming a second electrode on a light emitting layer of the transparent substrate, The method of manufacturing an organic electroluminescent device, characterized in that the filling of the fluorescent dye into the organic dye is performed by an inkjet method using a solution in which the fluorescent dye is dissolved in an organic solvent.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
A method for manufacturing an organic electroluminescence device according to an embodiment of the present invention will be described below with reference to FIG.
1A and 1B are cross-sectional views illustrating a method for manufacturing an organic EL device according to the present invention, wherein FIG. 1A shows a (step of filling a luminescent dye into a concave portion of a stamp substrate), and FIG. ), And (C) shows a (fluorescent dye diffusion step for each color).
The same components as those of the conventional example are denoted by the same reference numerals, and the description thereof will be omitted.
[0020]
(Process of filling luminescent dye into recesses on stamp substrate)
As shown in FIG. 1A, after performing the same steps as (first step) and (second step) in the conventional method for manufacturing an organic EL element, a solution in which the dye material 3 is dissolved in an organic solvent is used. Is filled in the concave portion 2 of the stamp substrate 1 by an ink jet printing method.
In the ink jet printing method used at this time, the iridium complex Ir (ppy) 3: Tris (2-phenylpyridine) iridium is dissolved in chloroform at 1 wt%, so that the recess 2 of the stamp substrate 1 can be easily filled. it can.
[0021]
(Transparent substrate preparation process)
As shown in FIG. 1B, a hole transport layer 6 and a light emitting layer 7 are sequentially formed on a transparent substrate 4 on which transparent electrodes 5 are formed in a stripe shape.
The hole transport layer 6 is formed by applying PEDOT.PSS of Bayer Co., Ltd. on the transparent electrode 5 of the transparent substrate 4 by spin coating, heating at 180 ° C. in a vacuum, and further adding chloroform to chloroform. Is formed by applying a solution obtained by dissolving 0.2% by weight in a solution by spin coating, and heating at 120 ° C. in vacuum.
[0022]
(Diffusion process of each color fluorescent dye)
Next, as shown in FIG. 1 (C), heating is performed in a state where the concave portion 2 side of the stamp substrate 1 and the light emitting layer 7 side of the transparent substrate 4 are placed in close contact and opposed to each other, and each color fluorescent light deposited in the concave portion 2 is heated. The dye 3 is diffused into the light emitting layer 7. Thus, the fluorescent light emitting layer 8 is formed in the light emitting layer 7. Here, the fluorescent dye 3 is a red fluorescent dye.
[0023]
Further, the same operation as described above is performed for the green fluorescent dye and the blue fluorescent dye to form the fluorescent emission layer 8 of these dyes.
At this time, each of the red fluorescent dye, the green fluorescent dye, and the blue fluorescent dye is formed in a predetermined pattern, for example, a staggered pattern or a vertical stripe pattern, and is formed without overlapping each other.
[0024]
Thereafter, the same steps as in the conventional method for manufacturing an organic EL element (seventh step) are performed to manufacture an organic EL element.
In addition, the dye coumarin 6 can be diffused into polyvinyl carbazole in an appropriate amount by heating in a nitrogen atmosphere at 120 ° C. for 30 minutes in the (fluorescent dye diffusion step for each color). At this time, either the transparent substrate 4 or the stamp substrate 1 may be heated, or both may be heated. Further, pressure may be applied as needed.
[0025]
As described above, according to the method for manufacturing an organic EL device of the embodiment of the present invention, after the solution in which the fluorescent dye 3 is dissolved in the organic solvent is filled into the concave portion 2 of the stamp substrate 1 by the inkjet printing method, the surface is filled. A transparent substrate 4 on which a transparent electrode 5, a hole transport layer 6, and a light emitting layer 7 are sequentially formed is prepared, and the transparent substrate 4 is placed on the stamp substrate 1 so that the concave portion 2 faces the light emitting layer 7. Since the fluorescent dye 3 is diffused into the light-emitting layer 7 by heating when placed, the fluorescent material 8 is formed, so that the adhesive material does not remain on the stamp substrate 1 as in the related art, so that color mixing is performed. Thus, an organic EL device capable of achieving high definition without causing the problem can be obtained.
[0026]
【The invention's effect】
According to the present invention, a transparent substrate in which a first electrode, a hole transport layer, and a light emitting layer are sequentially laminated on a surface in advance, and a stamp substrate having a concave portion formed on the surface are prepared. The concave portion is filled with a luminescent dye, and then the light emitting layer and the concave portion are arranged to face each other, and the transparent substrate and the stamp substrate are placed in close contact with each other. And then, after separating the stamp substrate from the transparent substrate, forming a second electrode on the light emitting layer of the transparent substrate, the method for manufacturing an organic electroluminescent element, wherein the stamp substrate Since the filling of the recesses with the luminescent dye is performed by an inkjet method using a solution in which the luminescent dye is dissolved in an organic solvent, an organic EL element that can achieve high definition without causing color mixture is obtained.
[Brief description of the drawings]
1A and 1B are cross-sectional views illustrating a method for manufacturing an organic electroluminescence device according to an embodiment of the present invention, wherein FIG. 1A illustrates a (step of filling a concave portion of a stamp substrate with a luminescent dye), and FIG. (C) shows a (transparent substrate preparation step), and (C) shows a (fluorescent dye diffusion step for each color).
FIGS. 2A and 2B are cross-sectional views illustrating a conventional method for manufacturing an organic EL device, in which FIG. 2A illustrates a (first step), FIG. 2B illustrates a (second step), and FIG. (C) shows (third step), (D) shows (fourth step), (E) shows (fifth step), and (F) shows (sixth step). , (G) show (seventh step).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Stamp substrate, 2 ... concave part, 3 ... fluorescent dye, 4 ... transparent substrate, 5 ... transparent electrode, 6 ... hole transport layer, 7 ... light emitting layer, 8 ... fluorescent light emitting layer, 11 ... metal electrode

Claims (1)

A transparent substrate in which a first electrode, a hole transport layer, and a light emitting layer are sequentially formed on the surface in advance and a stamp substrate having a concave portion formed on the surface are prepared, and then the concave portion of the stamp substrate is filled with a fluorescent dye. Then, after the light emitting layer and the concave portion are disposed to face each other and the transparent substrate and the stamp substrate are disposed in close contact with each other, and then heated, the fluorescent dye in the concave portion is diffused into the light emitting layer. In a method for manufacturing an organic electroluminescent element, the stamp substrate is separated from the transparent substrate, and then a second electrode is formed on a light emitting layer of the transparent substrate.
The method of manufacturing an organic electroluminescent device, wherein the filling of the fluorescent dye into the concave portion of the stamp substrate is performed by an inkjet method using a solution in which the fluorescent dye is dissolved in an organic solvent.

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