JP2003142277A - Organic el color display, and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL color display of which, film thickness of an organic compound material layer except light emitting layer can be set according to its function, capable of outputting light with high efficiency by taking various reflections into consideration, capable of keeping a good productivity. SOLUTION: An organic EL element is formed by sequentially laminating a transparent electrode 3, a layer 5A with hole transport function, light emitting layers 50R, 50B, 50C, a layer 5B with electron transport function, and a metal electrode 6 on a transparent substrate. The organic EL color display, using the above organic element as components, is composed by arranging a plurality of organic EL elements having the light emitting layer lighting in various colors according to the variation of organic compound materials, and the thickness of the transparent electrodes 3 of respective organic EL elements are made different from each other according to the color of emitted light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL color display including an organic EL (electroluminescence) element composed of a light emitting layer exhibiting a plurality of emission colors and a method for manufacturing the same.

[0002]

2. Description of the Related Art An organic EL display has an organic EL element as a basic element and displays an image by turning on or off an organic EL element formed on a flat substrate. The organic EL element is such that electrodes having a predetermined area are arranged to face each other, one is an anode to which a positive voltage is applied, the other is a cathode to which a negative voltage is applied, and an organic compound material layer including a light emitting layer is provided between the electrodes. When a voltage is applied between the electrodes, electrons are injected from the cathode into the light-emitting layer and holes from the anode into the light-emitting layer, and electron-hole recombination occurs in the light-emitting layer. It is a surface emitting element that emits light. A flat panel display capable of displaying a high-definition image can be formed by forming the organic EL element as a unit surface emitting element on a flat substrate in a matrix shape and driving the dot matrix.

Further, in response to the development of organic EL devices exhibiting R, G, and B emission colors with high color purity by research on organic compound materials, the devices of each color are arranged for each pixel. , An organic EL color display for full-color display has been developed. FIG. 8 is an explanatory view showing the element structure.

In the figure, a TFT 2 is formed on a substrate 1 made of transparent glass or the like.
A transparent electrode 3 (anode) made of a transparent conductive material such as is independently formed for each element. An insulating film 4 made of polyimide or the like is formed between the transparent electrodes 3.
Then, a plurality of organic compound material layers 5 are formed on the transparent electrode 3, and the organic compound material layers 5 are covered,
A metal electrode (cathode) 6 made of Al or the like is formed.
The organic compound material layer 5 is a hole transporting functional layer (hole injection layer 51, formed on the transparent electrode 3 and the insulating film 4 on the substrate 1).
Hole transport layer 52), and light emitting layers 50B, 5 formed thereon, which emit different colors depending on different organic compound materials.
0G, 50R, and an electron transporting functional layer (electron transporting layer 53, electron injection layer 54) formed thereon. Further, the area of the arrow between the broken lines indicates the light emitting area of each color of RGB.

In the organic EL color display having such an element structure, the light emitting layers 52B, 52G, 5
As light emitted from 2R and emitted from the substrate 1, light emitted from the substrate 1 directly through the transparent electrode 3, light emitted to the metal electrode 6 side and reflected from the surface of the metal electrode 3 and emitted from the substrate 1. It is known that there is light emitted from the substrate 1 after being reflected at each interface of the substrate 1, the transparent electrode 3 and the multilayered organic compound material layer 5, and these lights interfere with each other to affect the output. ing. In Japanese Patent Laid-Open No. 2000-323277, each layer of the organic compound material layer except the light emitting layer is set to have a different film thickness corresponding to the color of emitted light, and the reflection interference phenomenon is utilized to improve the efficiency of the light for extracting each color. It is described that the

In the above description, an active matrix type organic EL color display has been described as an example.
In the simple matrix (passive) type organic EL color display, there is no big difference in the element structure itself, and similarly, the output efficiency is improved by utilizing the reflection interference phenomenon.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the one described in Japanese Patent Publication No. 323277, it is premised that the film thickness of the transparent electrode is constant, and therefore, a reflection interference phenomenon is intended for reflected light reflected at the boundary between the organic compound material layer and the transparent electrode. However, there is a problem that it is not possible to increase the efficiency of the extracted light in consideration of the reflection interference phenomenon that is intended for the reflected light reflected at the boundary between the transparent electrode and the substrate. Further, the organic compound material layer excluding the light emitting layer is set to a different film thickness for each color, but the film thickness of the organic compound material layer should be set in order to fully exhibit its function. However, if this film thickness is set in consideration of the reflection interference phenomenon, there is a problem that the voltage / luminance efficiency of each color light emitting layer is lowered.

Further, the hole transporting function layer and the electron transporting function layer, which are organic compound material layers excluding the light emitting layer, are generally made of the same material and have a uniform film thickness for each function regardless of each color. However, if the film thickness of each functional layer is made different for each color, there is a problem that productivity is deteriorated.

The present invention has been proposed in order to deal with such a situation, and it is possible to achieve high efficiency of extracted light in consideration of various reflected lights, and to eliminate the light emitting layer. Another object of the present invention is to provide an organic EL color display in which a film thickness of the organic compound material layer can be set according to its function, and good productivity can be secured, and a manufacturing method thereof.

[0010]

In order to achieve the above object, the organic EL color display according to claims 1 to 10 of the present invention has the following features.

The invention according to claim 1 is a different organic compound material including an organic EL element formed by sequentially laminating a transparent electrode, a plurality of organic compound material layers including at least a light emitting layer, and a metal electrode on a transparent substrate. According to an organic EL color display in which a plurality of the organic EL elements including the light emitting layers exhibiting different emission colors are arranged, the transparent electrode of each organic EL element has a different film thickness corresponding to the emission color. Characterize.

The invention according to claim 2 is based on the organic EL color display according to claim 1, wherein at least one of the functional layers having the same function among the organic compound material layers excluding the light emitting layer is at least one layer. , And has a constant film thickness.

The invention according to claim 3 is based on the organic EL color display according to claim 2, wherein the functional layer having a constant film thickness is made of the same organic compound material for all the organic EL elements. Characterize.

The invention according to claim 4 is based on the organic EL color display according to claim 2 or 3, and the functional layer having the constant film thickness is a hole transport layer or a hole injection layer laminated on the anode side. It is characterized by being a layer.

The invention according to claim 5 is based on the organic EL color display according to claim 4, characterized in that the hole injection layer is laminated between the hole transport layer and the anode. To do.

The invention according to claim 6 is based on the organic EL color display according to claim 2 or 3, and the functional layer having a constant film thickness is an electron transport layer laminated on the cathode side. And

The invention according to claim 7 is based on the organic EL color display according to claim 6, and is characterized in that an electron injection layer is laminated between the electron transport layer and the cathode.

The invention according to claim 8 is premised on the organic EL color display according to any one of claims 1 to 7, from the light emitting interface of the light emitting layer which emits light with a wavelength λ as a central wavelength to the transparent electrode. The organic compound material layer and the transparent electrode are formed to have a film thickness such that an optical distance to the boundary with the transparent substrate is substantially equal to an even multiple of λ / 4.

The invention according to claim 9 is based on the organic EL color display according to any one of claims 1 to 5, and the transparent electrode is formed from the light emitting interface of the light emitting layer which emits light with a wavelength λ as a central wavelength. The optical distance to the boundary with the transparent substrate is substantially equal to an even multiple of λ / 4, and the optical distance from the light emitting interface of the light emitting layer to the interface of the metal electrode is λ.
It is characterized in that the organic compound material layer and the transparent electrode are formed with a film thickness that is substantially equal to an odd multiple of / 4.

The invention according to claim 10 is based on the organic EL color display according to claim 9, wherein the optical distance from the light emitting interface of the light emitting layer to the boundary between the organic compound material layer and the transparent electrode is λ / The organic compound material is formed into a film having a film thickness that is approximately equal to an odd multiple of 4.

Further, the method for manufacturing an organic EL color display according to claims 11 to 16 of the present invention has the following features.

The invention according to claim 11 is characterized in that an organic EL element formed by sequentially laminating a transparent electrode, a plurality of organic compound material layers including at least a light emitting layer, and a metal electrode on a transparent substrate is used as a component, and different organic compound materials are used. In a method for manufacturing an organic EL color display in which a plurality of the organic EL elements having the light emitting layers exhibiting different light emitting colors are arranged, a step of forming the transparent electrodes in different film thicknesses corresponding to the light emitting colors is performed. In addition to the above, all of the organic EL elements are characterized by having at least one or more common laminating step of laminating continuous common layers made of the same organic compound material and having a constant film thickness.

The invention according to claim 12 is based on the method for manufacturing an organic EL color display according to claim 11, wherein the common layer is a hole transport layer or a hole injection layer laminated between the transparent electrode and the common layer. Is characterized in that.

The invention according to claim 13 is the method for manufacturing an organic EL color display according to claim 11 or 12, wherein the common layer is an electron transport layer, and an electron injection layer is laminated between the common layer and the metal electrode. It is characterized by

The invention according to claim 14 relates to claims 11 to 1.
4. The method for manufacturing an organic EL color display according to any one of 3 above, wherein an optical distance from a light emitting interface of the light emitting layer that emits light with a wavelength λ as a central wavelength to a boundary between the transparent electrode and the transparent substrate is λ / 4. The organic compound material layer and the transparent electrode are formed to have a film thickness that is substantially equal to an even multiple.

The invention according to claim 15 relates to claims 11 to 1.
4. The method for manufacturing an organic EL color display according to any one of 3 above, wherein an optical distance from a light emitting interface of the light emitting layer that emits light with a wavelength λ as a central wavelength to a boundary between the transparent electrode and the transparent substrate is λ / It is almost equal to an even multiple of 4,
In addition, the organic compound material layer and the transparent electrode are formed with a film thickness such that the optical distance from the light emitting interface of the light emitting layer to the boundary of the metal electrode is approximately equal to an odd multiple of λ / 4. Characterize.

According to a sixteenth aspect of the present invention, in the method for manufacturing an organic EL color display according to the fifteenth aspect, an optical distance from a light emitting interface of the light emitting layer to a boundary between the organic compound material layer and the transparent electrode is λ. The organic compound material layer is formed to have a film thickness that is approximately equal to an odd multiple of / 4.

The invention according to each of the claims has the following effects.

Claims 1 to 7 or Claims 11, 12, and 13
According to the invention, by setting the film thickness of the transparent electrode to different film thicknesses corresponding to the emission color, the reflected light reflected at the boundary between the organic compound material layer and the transparent electrode and the boundary between the transparent electrode and the substrate can be obtained. In consideration of both the reflected light reflected by and the high efficiency due to the interference of the extracted light can be set. Further, when achieving high efficiency by interference only by the transparent electrode, each functional layer of the organic compound material layer should have a film thickness corresponding to each function or a uniform film thickness considering the productivity. Will be possible. This makes it possible to achieve high efficiency of extracted light while optimizing productivity or luminous efficiency of the light emitting layer.

In particular, it is possible to improve productivity by forming at least one of the functional layers of the organic compound material layer to have a constant film thickness on the entire surface of the display or to form the same organic compound material. Become. The functional layer having a constant film thickness or the same material can be a hole transport layer or a hole injection layer laminated from the light emitting layer to the anode side, or an electron transport layer laminated from the light emitting layer to the cathode side. .

According to the invention of claim 8 or claim 14,
In addition to the above-mentioned action, the efficiency of the extracted light is improved by considering the reflection interference phenomenon that is intended for the light emitted from the light emitting layer, reflected at the boundary between the transparent electrode and the transparent substrate, and returned to the light emitting layer side again. Can be achieved.

According to the invention of claim 9 or claim 15,
In addition to the above-mentioned action, light emitted from the light emitting layer and reflected at the boundary between the transparent electrode and the transparent substrate and returning to the light emitting layer side again and emitted from the light emitting layer in the rear direction and reflected at the interface of the metal electrode It is possible to achieve high efficiency of extracted light in consideration of the reflection interference phenomenon for the light directed to the front substrate side.

According to the tenth or sixteenth aspect of the invention, in addition to the above-mentioned action, the light emitted from the light emitting layer, reflected at the boundary between the organic compound material layer and the transparent electrode, and returned to the light emitting layer side again. Considering the targeted reflection interference phenomenon, it is possible to achieve high efficiency of the extracted light.

[0034]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing an embodiment corresponding to claims 1, 8 and 10 in an organic EL color display of the present invention. The figure shows the layer structure in the light emitting regions of RGB colors. In this embodiment, the film thicknesses of the organic compound material layer of each color and the transparent electrode are all optical film thicknesses. The organic EL color display has a plurality of organic EL elements as elements, and each organic EL element includes a light emitting layer that emits different emission colors depending on different organic compound materials. It forms an EL color display. Each organic EL element includes a substrate 1 made of transparent glass or the like, a transparent electrode 3 made of ITO or the like formed thereon,
A hole transporting functional layer 5A forming the organic compound material layer 5, a light emitting layer 50R (50G, 50B), an electron transporting functional layer 5B,
And a metal electrode 6 made of Al or the like, and the metal electrode 6 is covered with a sealing material (not shown) made of SiN ₄ or the like.

In each organic EL element, the light emitting layers 50R, 50G, and 50B, which are independently and separately laminated, are made of different organic compound materials that exhibit different emission colors of red, green, and blue when a current is applied. The EL color display performs color display by using a group of organic EL elements of red, green and blue emission colors as one pixel and arranging a plurality of these pixels in a matrix.

First, the reflection interference phenomenon in the organic EL element will be described with reference to FIG. Here, the electron transporting functional layer 5B, the hole transporting functional layer 5A, and the transparent electrode 3 have refractive indices of n1, n2, and n3, respectively, and have respective film thicknesses of d1 and d.
2, d3. Then, the refractive index of the substrate 1 is set to n4.
Then, it is assumed that there is a relationship of n1≈n2 <n3> n4.

In this case, the mode of light to be considered as the object of the reflection interference phenomenon is from the light emitting interface 50a of the light emitting layer 50 (the interface between the light emitting layer 50 and the hole transporting functional layer 5A is the light emitting interface). Light a emitted to the front surface, light a ′ emitted from the light emitting interface 50a to the rear surface, light b emitted from the light emitting interface 50a to the rear surface and reflected at the interface of the metal electrode, light emitting interface 50.
Light c emitted from a to the front surface, reflected at the boundary between the hole transporting functional layer 5A and the transparent electrode 3 and returning to the light emitting interface 50a again,
The light d is emitted from the light emitting interface 50a to the front surface, reflected at the boundary between the transparent electrode 3 and the substrate 1 and returned to the light emitting interface 50a again. Although the actual light emitting region largely depends on the device structure and the organic compound material used, it is considered that the light emitting region is distributed over several to several tens of nm from the interface between the light emitting layer 50 and the hole transporting functional layer 5A. The light emission interface 50a is defined, and the reflection interference phenomenon is examined by the optical distance from the light emission interface 50a.

Then, the condition that the light a of the wavelength λ and the light b are intensified is as expressed by the equation (1), that is, the optics from the light emitting interface 50a of the light emitting layer emitting light with the wavelength λ as the central wavelength to the interface of the metal electrode 6. The distance n1 · d1 is an odd multiple of λ / 4.

[0039]

[Equation 1]

The condition that the light a'of the wavelength λ and the light d are intensified is as shown in the equation (2), that is, from the light emitting interface 50a of the light emitting layer which emits light with the wavelength λ as the central wavelength to the transparent electrode 3 and the substrate 1. Optical distance to the boundary of (n2 ・ d2 + n3 ・ d
3) is an even multiple of λ / 4.

[0041]

[Equation 2]

Further, the condition that the light a'of the central wavelength λ and the light c are intensified is as shown in the formula (3), that is, from the light emitting interface 50a of the light emitting layer emitting light with the wavelength λ as the central wavelength to the organic compound material layer 5. Optical distance to the boundary with the transparent electrode 3 (n2
-D2) is an odd multiple of λ / 4.

[0043]

[Equation 3]

Therefore, the relationships of the optical distances that satisfy all the expressions (1) to (3) are as follows.

[0045]

[Equation 4]

[0046]

[Equation 5] In the embodiment of FIG. 1, for the electron transporting functional layer 5B, the hole transporting functional layer 5A, and the transparent electrode 3 in each color of RGB,
Central wavelength corresponding to RGB (λ _R = 650 nm, λ _G =
520 nm, λ _B = 460 nm) to λ _R / 4, λ _G /
4, λ _B / 4 is calculated and the optical distance of each layer is set as follows from the equation (5).

[0047]

[Equation 6]

Here, the refractive index of the transparent electrode 3 (ITO) for each color is n3 (λ _R ) = 1.81, n3 (λ _G ) = 1.
Since 94, n4 (λ _B ) = 2.00, the transparent electrode 3
The film thickness (nm) for each color is d3 (λ _R ) = 90, d3
(Λ _G ) = 67 and d4 (λ _B ) = 58. In this way, by setting the film thickness d3 of each color of the transparent electrode 3 to be different depending on the emission color, all of the formulas (1) to (3) are satisfied and all the considered lights are mutually strengthened. Settings can be made, and the light emitted from each color light emitting layer can be extracted most efficiently.

[Setting Example 1] The electron transporting functional layer is Alq, the hole transporting functional layer is NPB, the transparent electrode is ITO, and the substrate is AS.
As glass, an example of setting in the embodiment of FIG. 1 is shown below. Here, n1 to n4 are wavelengths (λ _R = 650 nm,
The measured values of the refractive index at λ _G = 520 nm and λ _B = 460 nm are shown.

[0050]

[Table 1]

Next, embodiments of the organic EL color display of the present invention corresponding to claims 1, 8 and 9 will be described with reference to FIG. 3 (in each of the following embodiments, the same as the above-mentioned embodiments). The parts are denoted by the same reference numerals and the description thereof is partially omitted.The drawing shows the layer structure in the light emitting regions of each of the RGB colors, and the light emitting layer is not shown.). In this embodiment, the light c emitted from the light emitting interface 50a to the front surface, reflected at the boundary between the hole transporting functional layer 5A and the transparent electrode 3 and returning to the light emitting interface 50a again is ignored, and the reflected light is
The light b emitted from the light emitting interface 50a to the rear surface and reflected at the interface of the metal electrode and the light b emitted from the light emitting interface 50a to the front surface and reflected at the boundary between the transparent electrode 3 and the substrate 1 and again the light emitting interface 5
Only the light d returning to 0a is considered.

Below, each layer boundary (electron transporting function layer; Alq, hole transporting function layer; NPB,
The actual measurement value of the electric field amplitude reflectance in the transparent electrode; ITO, substrate; AS glass) is shown.

[0053]

[Table 2]

As is clear from this table, the reflectance at the boundary between the organic compound material layer or the organic compound material layer and the transparent electrode 3 is actually the reflectance at the boundary between the transparent electrode 3 and the substrate 1. It is quite small in comparison, and ignoring the reflected light of the former is not a practical problem. Therefore, only the above formulas (1) and (2), that is, the optical distance (n2 · d2 + n) from the light emitting interface 50a of the light emitting layer that emits light with the wavelength λ as the central wavelength to the boundary between the transparent electrode 3 and the substrate 1
3 · d3) is an even multiple of λ / 4, and the emission interface 50
From the relationship that the optical distance d1 from a to the interface of the metal electrode 6 is an odd multiple of λ / 4, the following relationship is obtained with m = 1.

[0055]

[Equation 7]

Here, for d2 and d3, for example, the film thickness is set so that the driving voltage is made uniform for each color. That is, when the hole transporting function layer is formed thick and the transparent electrode is thinned, the current luminance characteristic does not change but the voltage luminance characteristic deteriorates. Therefore, by using this, the driving condition should be the same for each color. The film thickness of the hole transporting functional layer d2 can be set. By setting the transparent electrode film thickness d3 to a different value for each color, it is possible to satisfy the expression (7), and it is also possible to achieve a practically high efficiency of extracted light. .

Next, an embodiment of the organic EL color display of the present invention corresponding to claims 2, 3, 4, 5, 8 and 9 will be described with reference to FIG. In this embodiment, similarly to the embodiment of FIG. 3, the reflection between the organic compound material layers and the reflection at the boundary between the organic compound material layer and the transparent electrode are ignored, and only n1 is obtained from the equations (1) and (2).・ D1 = λ / 4,
The condition of n2 · d2 + n3 · d3 = λ / 2 is obtained, and the film thickness d2 of the hole transporting functional layer 5A is set as a constant value common to each color. According to this, the hole transporting function layer 5A can be uniformly formed on the entire surface of the panel after the transparent electrode 3 film is formed, so that the productivity can be improved. The hole transporting function layer 5A may be a single layer of a hole transporting layer made of a single material such as NPB, or a hole made of a single material made of CuPC or the like between the hole transporting layer and the transparent electrode. It may be a stack of injection layers.

[Setting Example 2] The electron transporting functional layer is Alq, the hole transporting functional layer is NPB, the transparent electrode is ITO, and the substrate is AS.
As glass, an example of setting in the embodiment of FIG. 4 is shown below. Here, n1 to n4 are wavelengths (λ _R = 650 nm,
The measured values of the refractive index at λ _G = 520 nm and λ _B = 460 nm are shown.

[0059]

[Table 3]

Next, an embodiment of the organic EL color display of the present invention corresponding to claims 6, 7 and 8 will be described with reference to FIG.
Explained by. In this embodiment, the transparent electrode 3 and the hole transporting functional layer 5A are the same as those in the embodiment of FIG. 4, and the thickness d1 of the electron transporting functional layer 5B on the cathode side is set to a constant value common to all colors. Is. In this case, if the film thickness d1 is set to a constant value common to all colors, the above formula (1) cannot be satisfied for all colors. Therefore, the film thickness d1 satisfying the expression (1) is set only for a specific color, and the film thickness d3 of the transparent electrode 3 is set.
Is set to a different value for each color, and the film thickness d2 of the hole transporting functional layer 5A is set so as to satisfy the expression (2). According to this, while achieving practically high efficiency of extraction light,
By making both the hole transporting functional layer 5A and the electron transporting functional layer 5B have a constant film thickness, the productivity can be further improved. In this case, the electron transporting functional layer 5B may be a single layer of an electron transporting layer made of a single material such as Alq, or a single layer made of Li ₂ O or the like between the electron transporting layer and the metal electrode 6. It may be a stack of electron injection layers of materials.

[Setting Example 3] The electron transporting functional layer is Alq, the hole transporting functional layer is NPB, the transparent electrode is ITO, and the substrate is AS.
As glass, an example of setting in the embodiment of FIG. 5 is shown below. Here, n1 to n4 are wavelengths (λ _R = 650 nm,
The measured values of the refractive index at λ _G = 520 nm and λ _B = 460 nm are shown.

[0062]

[Table 4]

The method of manufacturing the organic EL color display according to the present invention will be described below. In FIG. 6, first,
As shown in FIG. 3A, RGs each made of ITO
The transparent electrode 3 for B is formed on the glass substrate 1. As shown in Table 4, the film thickness d3 of the transparent electrode is set in advance so as to have different values corresponding to the respective emission colors of RGB, and the vapor deposition time is set for each color using a mask for each color. A desired film thickness is formed.

Next, as shown in FIG. 7B, the hole transporting functional layer 5A is uniformly formed on the transparent electrode 3 by vacuum vapor deposition or the like. This hole transporting functional layer 5A is formed of NP as described above.
B may be a single layer, or CuPC may be used as the hole injection layer.
You may make it laminate | stack NPB after laminating | stacking such single layers. In any case, the hole transporting function layer 5A is formed by stacking a common layer made of the same organic compound material and having a continuous constant film thickness.

Next, as shown in FIG. 7C, the light emitting layer 50 is formed for each color, and the electron transporting functional layer 5B is uniformly formed thereon by vacuum vapor deposition or the like. The electron transporting function layer 5B may be a single layer of Alq as described above,
After stacking this single layer, a single layer of Li ₂ O or the like may be stacked as the electron injection layer. In any case, the formation of the electron transporting function layer 5B is a step of stacking a common layer made of the same organic compound material and having a continuous constant film thickness. Then, as shown in FIG. 3D, a metal electrode 6 having a low work function such as Al-Li is formed on the electron transporting functional layer 5B.
Is formed by a means such as vapor deposition or sputtering, and is further covered with a sealing material (not shown).

According to this manufacturing method, the step of forming the transparent electrode 3 requires a complicated step of setting the film thickness for each color using a mask or the like, but the subsequent film forming step can be simplified. . In particular, considering that the material is distributed with the transparent electrode 3 formed on the substrate, the productivity of the display can be significantly improved.

By setting the hole transporting function layer 5A and the electron transporting function layer 5B so as to have the film thickness d2 and the film thickness d1 in Table 4, the extracted light due to the reflection interference phenomenon is practically effective. It is also possible to achieve high efficiency.

FIG. 7 is an explanatory view showing another embodiment of the method for manufacturing an organic EL color display according to the present invention. This is an embodiment for obtaining [Setting Example 1], which places the highest importance on increasing the efficiency of the extracted light of each color. First, as shown in FIG. 3A, the RGB transparent electrodes 3 made of ITO are formed on the glass substrate 1 so that the film thickness d3 becomes the value shown in Table 1. Then, the common layer 5A ′ of the hole transporting functional layer is formed on the transparent electrode 3 with a continuous constant film thickness made of the same organic compound material. The film thickness of the common layer 5A ′ is the minimum value of d2 in Table 1 (59
nm).

Next, as shown in FIG. 9B, a hole transporting functional layer is added to R and G by a required thickness to form RG.
The hole transporting functional layer 5A is formed so that the film thickness d2 of each color B becomes the value shown in Table 1. Further, as shown in FIG. 7C, after forming the light emitting layer 50 for each color, the common layer 5B ′ of the electron transporting functional layer is formed with a continuous constant film thickness made of the same organic compound material. The film thickness of the common layer 5B 'is set to the minimum value (62 nm) of d1 in Table 1.

Then, as shown in FIG. 7D, an electron transporting functional layer is added to R and G by a required thickness,
The electron transporting functional layer 5B is formed so that the film thickness d1 of each color of RGB becomes the value shown in Table 1. After that, the metal electrode 6 is formed on the electron transporting functional layer 5B as in the above-described embodiment, and the metal electrode 6 is further covered with a sealing material. Also in this embodiment, the hole transporting functional layer 5A is N as in the above-described embodiments.
A single layer such as PB may be used, or Cu may be used as the hole injection layer.
NPB may be laminated after laminating a single layer such as PC, and the electron transporting functional layer 5B may be a single layer such as Alq. it may be stacked monolayers of li 2 _O or the like.

According to this manufacturing method, the above (1)-
By setting the film thickness that satisfies all of the expressions (3), it is possible to maximize the efficiency of the extracted light of each color, and to form the common layer first when forming the organic compound material layer. , So I added layers of each color after that,
It becomes possible to shorten the film formation time and improve the productivity.

[0072]

Since the present invention is constructed in this way,
It is possible to achieve high efficiency of extracted light by taking various reflected light into consideration, and the organic compound material layer except the light emitting layer can be set to a film thickness according to its function, and good production can be achieved. It is possible to secure the sex.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of an organic EL color display of the present invention.

FIG. 2 is an explanatory diagram illustrating a reflection interference phenomenon in an organic EL element.

FIG. 3 is an explanatory diagram showing an embodiment of the organic EL color display of the present invention.

FIG. 4 is an explanatory diagram showing an embodiment of the organic EL color display of the present invention.

FIG. 5 is an explanatory diagram showing an embodiment of the organic EL color display of the present invention.

FIG. 6 is an explanatory diagram showing an embodiment of a method for manufacturing an organic EL color display of the present invention.

FIG. 7 is an explanatory diagram showing an embodiment of a method for manufacturing an organic EL color display of the present invention.

FIG. 8 is an explanatory diagram showing a device structure of a conventional organic EL color display.

[Explanation of symbols]

1 substrate 2 TFT 3 transparent electrodes 4 insulating film 5 Organic compound material layer 5A Hole transporting functional layer 5B Electron transport functional layer 50 light emitting layer 6 metal electrodes

Claims (16)

[Claims] 1. An organic EL device comprising a transparent electrode, a plurality of organic compound material layers including at least a light-emitting layer, and a metal electrode, which are sequentially laminated on a transparent substrate, is used as an element to exhibit different emission colors depending on different organic compound materials. In an organic EL color display in which a plurality of the organic EL elements composed of the light emitting layer are arranged, the transparent electrode of each organic EL element has a different film thickness corresponding to an emission color. display. 2. The at least one functional layer having the same function among the organic compound material layers except the light emitting layer has a constant film thickness.
The described organic EL color display. 3. The organic EL color display according to claim 2, wherein the functional layer having a constant film thickness is made of the same organic compound material for all the organic EL elements. 4. The organic EL color display according to claim 2, wherein the functional layer having a constant thickness is a hole transport layer or a hole injection layer laminated on the anode side. 5. The hole injection layer is laminated between the hole transport layer and the anode.
The described organic EL color display. 6. The organic EL color display according to claim 2, wherein the functional layer having a constant film thickness is an electron transport layer laminated on the cathode side. 7. The organic EL color display according to claim 6, wherein an electron injection layer is laminated between the electron transport layer and the cathode. 8. A film thickness such that an optical distance from a light emitting interface of the light emitting layer that emits light with a wavelength λ as a central wavelength to a boundary between the transparent electrode and the transparent substrate is substantially equal to an even multiple of λ / 4. The organic EL color display according to any one of claims 1 to 7, wherein the organic compound material layer and the transparent electrode are formed. 9. The optical distance from the light emitting interface of the light emitting layer, which emits light with a wavelength of λ as a central wavelength, to the boundary between the transparent electrode and the transparent substrate is substantially equal to an even multiple of λ / 4, and The organic compound material layer and the transparent electrode are formed with a film thickness such that the optical distance from the light emitting interface to the interface of the metal electrode is approximately equal to an odd multiple of λ / 4. Organic E according to any one of 1 to 5
L color display. 10. The optical distance from the light emitting interface of the light emitting layer to the boundary between the organic compound material layer and the transparent electrode is λ.
The organic EL color display according to claim 9, wherein the organic compound material is formed into a film having a film thickness that is substantially equal to an odd multiple of / 4. 11. An organic EL device comprising a transparent electrode, a plurality of organic compound material layers including at least a light emitting layer, and a metal electrode, which are sequentially laminated on a transparent substrate, is used as an element to exhibit different emission colors depending on different organic compound materials. In a method for manufacturing an organic EL color display in which a plurality of the organic EL elements each including the light emitting layer are arranged, the method includes a step of forming the transparent electrodes to have different film thicknesses corresponding to emission colors. A method for manufacturing an organic EL color display, characterized by comprising at least one or more common lamination steps of laminating continuous common layers made of the same organic compound material and having a constant film thickness for all of the elements. 12. The method of manufacturing an organic EL color display according to claim 11, wherein the common layer is a hole transport layer or a hole injection layer laminated between the transparent electrode and the common layer. 13. The method for manufacturing an organic EL color display according to claim 11, wherein the common layer is an electron transport layer, and an electron injection layer is laminated between the common layer and the metal electrode. 14. A film thickness such that an optical distance from a light emitting interface of the light emitting layer which emits light with a wavelength λ as a central wavelength to a boundary between the transparent electrode and the transparent substrate is substantially equal to an even multiple of λ / 4. The method for manufacturing an organic EL color display according to any one of claims 11 to 13, wherein the organic compound material layer and the transparent electrode are formed into a film. 15. The optical distance from the light emitting interface of the light emitting layer, which emits light with a wavelength λ as the central wavelength, to the boundary between the transparent electrode and the transparent substrate is substantially equal to an even multiple of λ / 4, and With a film thickness such that the optical distance from the light emitting interface to the boundary of the metal electrode is approximately equal to an odd multiple of λ / 4,
The method for manufacturing an organic EL color display according to claim 11, wherein the organic compound material layer and the transparent electrode are formed. 16. The optical distance from the light emitting interface of the light emitting layer to the boundary between the organic compound material layer and the transparent electrode is λ.
2. The organic compound material layer is formed to have a film thickness that is substantially equal to an odd multiple of / 4.
5. The method for manufacturing an organic EL color display described in 5.