JPH11204258A - Electroluminescence element and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture a layered product presenting luminescent colors of red, green and blue (R, G, B) in a simple process at a low cost. SOLUTION: Transparent electrodes 5 common to at least three kinds of electroluminescence element sections 21B, 21G, 21R are formed on a glass substrate 6 common to the electroluminescence element sections 21B, 21G, 21R, and hole transportation layers 4a, 4b made of a common hole transportation layer forming material layer are formed on regions including the electroluminescence element sections 21b, 21G, 21R on the transparent electrodes 5. Electron transportation layers 2 made of a common electron transportation forming material layer are formed on the regions including the electroluminescence element sections 21B, 21G, 21R on the regions including the hole transportation layers 4a, 4b, and cathode electrodes 1 of the electroluminescence element sections 21B, 21G, 21R are formed to face the transparent electrodes 5 on the electron transportation layers 2. The blue electroluminescence elements 21B have hole block layers 33, and the red electroluminescence element sections 21R have red luminescent layers 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent device and a method of manufacturing the same, for example, a self-luminous flat display, and in particular, a display such as an organic electroluminescent color display using an organic thin film as an electroluminescent layer. The present invention relates to an electroluminescent element suitable for an element or a light emitting device and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the importance of interfaces between humans and machines, such as multimedia-oriented products, has been increasing. In order for humans to operate the machine more comfortably and efficiently, it is necessary to extract information from the operated machine in a simple, instantaneous, and sufficient amount without errors. Research has been conducted on display elements.

Further, with the miniaturization of machines, the demand for miniaturization and thinning of display elements is increasing every day.

[0004] For example, there has been a remarkable progress in miniaturization of laptop information processing devices which are integrated with display elements, such as notebook personal computers and notebook word processors. There are also great innovations regarding

[0005] Today, the liquid crystal display is used as an interface for various products.
It is widely used in our everyday products, including calculators.

[0006] These liquid crystal displays have been studied as small-sized to large-capacity display devices as interfaces between humans and machines as the center of display elements, taking advantage of the characteristics that liquid crystals are driven at low voltage and low power consumption. .

However, since this liquid crystal display is not self-luminous, it requires a backlight, and this backlight requires more power than driving the liquid crystal. Is shorter and there are restrictions on use.

Another problem is that the liquid crystal display is not suitable for a large display device such as a large display because the viewing angle is narrow.

Further, since the liquid crystal display is a display method based on the alignment state of liquid crystal molecules, it is considered that a significant problem that the contrast varies depending on the angle even within the viewing angle.

In view of the driving method, the active matrix method, which is one of the driving methods, shows a response speed sufficient to handle moving images.
Since a driving circuit is used, it is difficult to increase the screen size due to pixel defects.

In a liquid crystal display, a simple matrix system, which is another driving system, is low in cost and relatively easy to enlarge the screen size, but does not have a sufficient response speed for handling moving images. There is a problem.

On the other hand, as a self-luminous display element, a plasma display element, an inorganic electroluminescent element, an organic electroluminescent element and the like have been studied.

The plasma display device uses plasma emission in a low-pressure gas for display, and is suitable for increasing the size and the capacity, but has problems in terms of thickness and cost.
Further, it requires a high voltage AC bias for driving, and is not suitable for portable devices.

As the inorganic electroluminescent device, a green light-emitting display or the like has been commercialized, but like the plasma display device, it is driven by an AC bias, and requires several hundred volts for driving, and is not practical.

However, due to the development of technology, three primary colors of R (red), G (green), and B (blue) necessary for color display display have been successfully emitted. It is difficult to control the emission wavelength and the like by using the method described above, and it is considered that full-color display is difficult.

On the other hand, the electroluminescence phenomenon caused by an organic compound is as follows.
It has been studied for a long time since the light emission phenomenon caused by carrier injection into an anthracene single crystal that emits strong fluorescence was discovered in the early 1960s. It was performed as a basic study of carrier injection into materials.

However, in 1987 Eastman Kodak
Since Tang et al. Announced a stacked organic thin-film electroluminescent device with an amorphous light-emitting layer capable of low-voltage driving and high-luminance light emission, the R, G, and B primary colors of light emission, stability, and brightness have been observed in various directions. Research and development on ascending, laminating structure, manufacturing method, etc. are being actively conducted.

Further, as a feature of the organic material, various new materials have been invented by molecular design and the like, and the color of the organic electroluminescent display element has excellent features such as low-voltage DC drive, thinness, and self-luminous property. Research on application to displays is also being actively pursued.

An organic electroluminescent device (hereinafter sometimes referred to as an organic EL device) has a thickness of 1 μm or less, and converts electric energy into light energy by injecting a current to emit light in a planar manner. It has ideal characteristics as a self-luminous display device.

FIG. 34 shows an example of a conventional organic EL device 10. In the organic EL device 10, an ITO (Indium tin oxide) transparent electrode 5, a hole transport layer 4, a light emitting layer 3, an electron transport layer 2, and a cathode (eg, an aluminum electrode) 1 are formed on a transparent substrate (eg, a glass substrate) 6. For example, they are sequentially formed by a vacuum deposition method.

Then, by selectively applying a DC voltage 7 between the transparent electrode 5 as an anode and the cathode 1, holes as carriers injected from the transparent electrode 5 pass through the hole transport layer 4. Electrons injected from the cathode 1 move through the electron transport layer 2 to cause recombination of electrons and holes, from which light emission 8 having a predetermined wavelength is generated, which can be observed from the transparent substrate 6 side.

The light-emitting layer 3 may use a light-emitting substance such as anthracene, naphthalene, phenanthrene, pyrene, chrysene, perylene, butadiene, coumarin, acridine, and stilbene. This can be contained in the electron transport layer 2.

FIG. 35 shows another conventional example.
An organic EL in which the light emitting layer 3 is omitted, the electron transporting layer 2 contains the light emitting substance as described above, and light emission 18 of a predetermined wavelength is generated from the interface between the electron transporting layer 2 and the hole transporting layer 4.
4 shows an element 20.

FIG. 36 shows a specific example of the above-mentioned organic EL device. That is, a laminated body of each organic layer (the hole transport layer 4, the light emitting layer 3, or the electron transport layer 2) is disposed between the cathode 1 and the anode 5, and these electrodes are crossed in a matrix to form a stripe. A luminance signal circuit 34 and a control circuit 35 with a built-in shift register apply a signal voltage in a time series to emit light at a number of intersection positions (pixels).

Therefore, with such a configuration, it can be used not only as a display but also as an image reproducing apparatus. The above-mentioned stripe patterns can be arranged for each of R, G, and B colors, and can be configured for full-color or multi-color.

In a display device composed of a plurality of pixels using such an organic EL element, the light emitting organic thin film layers 2, 3, and 4 are generally sandwiched between the transparent electrode 5 and the metal electrode 1, and Light is emitted to the electrode 5 side.

[0027]

However, the organic EL device as described above still has an unsolved problem.

In order to apply an organic EL element to a color display, stable emission of the three primary colors R, G, and B is an essential condition. If completely different material systems are used, the process becomes extremely complicated and takes time.

An object of the present invention is to provide an electroluminescent device having an element structure which can be manufactured simply and at low cost and can emit light stably, and a method for manufacturing the same.

[0030]

Means for Solving the Problems The present inventors diligently study the above-mentioned circumstances, and use simple and inexpensive materials by using as common a material as possible in at least three types of laminates having light emitting regions of each color. The present inventors arrived at the present invention by finding that a device can be manufactured.

That is, the present invention has at least three types of organic substance laminates in which the light emitting region is independently present in the hole transport layer and the electron transport layer, and these laminates are formed of a common material layer. An electroluminescent device, comprising the hole transport layer and the electron transport layer made of a common material layer, and emitting at least three colors of light.

According to the electroluminescent device of the present invention, the hole transport layer and the electron transport layer are formed of a common material layer between the laminates in which the light emitting regions are independently provided in the hole transport layer and the electron transport layer. Since it is formed, it is possible to easily and inexpensively produce a laminate that emits each color of light by a simple process. Further, by forming the common layers with a large aperture mask over the entire effective pixel region, the film formability or step coverage is improved, and the leakage current between the cathode and the anode can be reduced.

According to the present invention, as a method of manufacturing the electroluminescent device of the present invention with good reproducibility, a first electrode common to at least three kinds of the laminates is formed on a common base during the manufacturing. Forming a common hole transport layer forming material on a region including at least three types of the stacked bodies on the first electrode to form each hole transport layer; A step of forming a common electron transport layer forming material on a region including at least three types of the stacked bodies to form each electron transport layer on the region including at least three types of the laminate; Forming each of the second electrodes of the laminated body to face the first electrode.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION In the electroluminescent device and the method for manufacturing the same according to the present invention, the light emitting region is made of an organic compound, and the laminate has at least three kinds of laminates made of an organic substance containing the light emitting region. In at least one of the laminates, it is desirable that blue light emission is obtained by electron-hole recombination in the hole transporting organic material.

According to such an electroluminescent device, light emission by electron-hole recombination can be obtained in the above-mentioned hole transporting organic material (that is, the hole transport layer is an electron-hole recombination region). The structure also serves as the light emitting layer)
As a result, stable and high-luminance light emission, particularly blue light emission, is possible even at low voltage driving.

Accordingly, the electroluminescent device (especially low-voltage driving, self-luminous,
In the case of a thin amorphous organic electroluminescent element, a long-life electroluminescent element having a hole transport layer also serving as a light emitting layer and providing long-term stable light emission can be provided.

That is, even in an organic electroluminescent device in which the hole transport layer is a light emitting layer, stable light emission with high luminance and high efficiency can be obtained.
Peak luminance of 550 in DC conversion even in pulse drive at 10,000 cd / m ² or more and 1/100 duty ratio in C drive
It is possible to obtain 00 cd / m ² or more.

Further, other than the blue light emitting element, green light emission,
Further, red light emission and yellow light emission by doping, and chromaticity by doping can be adjusted. As a result, it is possible to produce an organic electroluminescent blue light-emitting device capable of obtaining blue light emission with excellent chromaticity at high luminance, and to shorten the time and the potential for material development. A guideline for designing electron transport materials can be provided.

In the electroluminescent device and the method of manufacturing the same according to the present invention, it is preferable that the light emitting region is mainly an organic hole transport layer, and that the hole transport layer has a hole blocking layer for causing the recombination.

It is preferable that the hole blocking layer is provided between the hole transport layer and the electron transport layer.

The highest occupied molecular orbital level of the hole block layer is the highest occupied molecule of each organic layer (particularly, the hole transport layer and the electron transport layer) stacked on both sides of the hole block layer. It is desirable to be at or below the highest occupied molecular orbital level which is lower in energy among the orbital levels.

The minimum unoccupied molecular orbital level of the hole block layer is the minimum unoccupied molecular orbital level of each of the organic layers (particularly, the hole transport layer and the electron transport layer) laminated on both sides of the hole block layer. It is desirable that the occupied molecular orbital level be higher than the lowest unoccupied molecular orbital level which is lower in energy and lower than the lowest unoccupied molecular orbital level which is higher in energy.

The hole block layer is desirably made of a non-luminescent material having a low fluorescence yield, and may have a multilayer structure of a plurality of layers.

Further, the material of the hole blocking layer is not limited in terms of material, but is to prevent the generation of exciplex (excimer: dimer) at the interface with the hole transporting light emitting layer (ie, decrease in luminous efficiency). In particular, it is preferable that the material is a non-luminescent material having a low fluorescence yield.

It is preferable that the light emitting region is made of a hole transporting material for short wavelength light emission. Further, as a material that can be used for the hole blocking layer, a phenanthroline derivative shown in FIG. 4 is preferable, and specific examples include, for example, structural formula 1 shown in FIG. 5, structural formula 2 shown in FIG. FIG.
8, structural formula 4 shown in FIG. 8, structural formula 5 shown in FIG. 9, structural formula 6 shown in FIG. 10, structural formula 7 shown in FIG.
Structural formula 8 shown in FIG. 12, structural formula 9 shown in FIG. 13, and FIG.
Each material of the structural formula 10 shown below is mentioned.

Further, the light emitting region is made of an organic compound, and at least three kinds of the above-mentioned laminates made of an organic substance containing the light emitting region are provided. It is desirable to obtain green light emission by electron-hole recombination.

Further, the light emitting region is made of an organic compound, and at least three kinds of the laminates made of an organic substance containing the light emitting region are provided. In at least one of these laminates, an electron transporting organic material is used. It is desirable to obtain red light emission by recombination of electrons and holes.

As described above, by stacking an organic layer for obtaining blue light emission due to electron-hole recombination in the light emitting region as a hole block layer, stable, high luminance, low voltage drive hole transporting light emission is obtained. The organic electroluminescent device having a layer can be obtained, and red or green light can be obtained by electron-hole recombination in the electron transport layer in the layered region of the organic material without the hole blocking layer. , G and B can be provided.

The above element is formed on an optically transparent substrate by
It is preferable that a transparent electrode, an organic layer (particularly, an organic hole transport layer, a hole block layer, an organic electron transport layer) and a metal electrode are sequentially laminated.

In this case, it is preferable that the transparent electrode, the organic layer, and the metal electrode are configured as an organic electroluminescent element in which a matrix pattern is formed on the same substrate.

As a result, the above-mentioned element is constituted as a suitable organic electroluminescent element, and is also suitable as an element for a color display.

Hereinafter, a preferred embodiment of the present invention will be described.

<First Embodiment> FIG. 3 is a schematic sectional view showing a main part of an organic EL element 21 according to a first embodiment of the present invention.

The organic EL device 21 according to the present embodiment is
At least three types of organic electroluminescent elements 21B (blue), 21G (green), and 21R (red) formed of a laminate of amorphous organic thin films are provided on a common glass substrate 6 for each color emission. .

In the blue light emitting element portion 21B shown in FIG. 3A, a glass or
(Indium Tin Oxide), a transparent electrode 5 made of Zn-doped indium oxide or the like (hereinafter the same) is formed by a method such as sputtering or vacuum evaporation, and a hole transport layer 4a for blue light emission is sequentially formed thereon. Hole transporting light emitting layer 4b, hole blocking layer 33, electron transporting layer (or electron transporting light emitting layer) 2, cathode electrode 1 as column electrode
Are laminated by a vacuum evaporation method.

In the green light emitting element portion 21G shown in FIG. 3B, the transparent electrode 5 made of ITO (Indium Tin Oxide) or the like is formed on a glass substrate 6 by a method such as sputtering or vacuum evaporation. The hole transporting layer 4a, the hole transporting light emitting layer 4b, the electron transporting layer 2 for emitting green light, and the cathode electrode 1 as a column electrode are sequentially laminated by a vacuum deposition method, and the hole blocking layer is not provided.

In the red light emitting element portion 21R shown in FIG. 3C, the transparent electrode 5 made of ITO (Indium Tin Oxide) or the like is formed on a glass substrate 6 by a method such as sputtering or vacuum evaporation. Sequentially, the hole transport layer 4
a, a hole transporting light emitting layer 4b, an electron transporting layer 32 for emitting red light, an electron transporting layer 2, and a cathode electrode 1 as a column electrode are laminated by a vacuum evaporation method.

The feature of the organic EL element 21 shown in FIG. 3 is that, on the glass substrate 6 common to the light emitting element sections 21B, 21G, and 21R, at least three types of light emitting element sections are transparent as row electrodes or line electrodes. An electrode 5 is formed, and on this transparent electrode, a hole transport layer 4a, 4a made of a common hole transport layer forming material is formed on a region including each light emitting element.
b, an electron transport layer 2 made of a common electron transport forming material is formed on a region including each light emitting element portion on the region including each of the hole transport layers, and further, each of these electron transport layers is formed. That is, the respective cathode electrodes 1 of the respective light emitting element portions are formed in a matrix pattern on the layer so as to face the transparent electrodes 5. However, each light emitting element section has a specific layer configuration, and the blue light emitting element section 21B has a hole block layer 33 in the stripe pattern, and the red light emitting element section 21R has the red light emitting layer 32 in the stripe pattern.

Therefore, in each light-emitting element portion, the light-emitting region has the hole transporting layer 4 (4a, 4b) and the electron transporting layer 2 formed of a common material, so that the light-emitting region has a striped shape exhibiting each color. The laminate (matrix) can be manufactured easily and at low cost by a simple process.
Moreover, by forming each of the common layers with a large aperture mask over the entire effective pixel region, the film formability or the step coverage is improved, and the leakage current between the cathode and the anode can be reduced.

The blue light emitting element portion 21B is
Is configured as a structure having the performance as a light emitting layer, and the basic structure is the same in other embodiments described later.

The feature of the element portion 21 B of the present embodiment is that the hole block layer 33 is inserted between the hole transport layer 4 and the electron transport layer 2 and laminated, so that Is promoted, and light emission in the hole transport layer 4 can be obtained.

FIG. 15 shows the above-described embodiment (FIG. 3).
(A)) is a diagram schematically showing a layered structure by a band model.

In FIG. 15, a cathode 1 made of Al and Al-Li (aluminum-lithium) and ITO
The bold lines (L ₁ , L ₂ ) shown in the layer of the transparent electrode 5 are the approximate work functions of the respective metals, and the upper bold lines l ₁ , l ₂ , l ₃ , l ₄ and numbers indicate the level of each of the lowest unoccupied molecular orbital (LUMO), thick line _{l 5, l 6, l 7} , l 8 and numerical lower indicates the level of the respective highest occupied molecular orbital (HOMO) ing. However, the energy level value in FIG. 15 is an example, and changes variously depending on the material.

In this organic EL device, as shown in FIG. 15, the holes h injected from the transparent electrode 5 as the anode move through the hole transport layer 4, while being injected from the metal electrode 1 of the cathode. The electrons e move through the electron transporting layer 2, and the electron-holes are transferred to the hole transporting light emitting layer 4.
Recombine to generate light.

Since the electrons e injected from the metal electrode 1 serving as the cathode have the property of moving to a lower energy level, the metal electrode 1, the electron transport layer 2, the hole blocking layer 33, the hole transporting light emitting layer 4b , Hole transport layer 4a
The lowest unoccupied molecular orbital (LUMO) level l of each layer in the order of
Hole transport light emitting layer 4b via the ₁ to l _4, it can be reached 4a.

On the other hand, an ITO transparent electrode 5 as an anode
The hole h injected from the hole has the property of moving to a higher energy level, and therefore the highest occupied molecular orbital (HOMO) level l of each layer in the order of the hole transport layer 4a, the hole transportable light emitting layer 4b, and the hole block layer 33. It can move to the electron transport layer 2 via _{5 to} l ₇ .

However, as shown in FIG. 15, the highest occupied molecular orbital (HOMO) level ₁₈ of the electron transport layer 2 is lower in energy than the highest occupied molecular orbital (HOMO) level _{17 of} the hole block layer 33. Therefore, the injected holes h are less likely to move from the hole block layer 33 to the electron transport layer 2 and fill the hole block layer 33.

As a result, the holes h filled in the hole blocking layer 33 promote the recombination of electrons and holes in the hole transporting layer 4, and the luminescent materials of the hole transporting luminescent layers 4 a and 4 b constituting the hole transporting layer 4 are formed. Will emit light.

As described above, by providing the hole blocking layer 33, the transport of holes h is effectively controlled in the hole blocking layer 33 so that the electron-hole recombination is efficiently generated in the hole transport layer 4. . Then, the hole transporting light emitting layers 4a, 4b emitting light by this.
Of these, mainly the light emitted by the hole transporting light emitting layer 4b adjacent to the hole blocking layer 33 is
Light emission of a specific wavelength (blue) is emitted as shown in FIG.

Originally, electron injection from the cathode electrode 1 and hole injection from the anode electrode 5 cause the electron transport layer 2 and the hole transport layer 4 to have electron-
Hole recombination occurs. Therefore, when the hole blocking layer 33 does not exist as described above, recombination of electrons and holes occurs at the interface between the electron transport layer 2 and the hole transport layer 4, and only long-wavelength light emission can be obtained. However, by providing the hole blocking layer 33 as in this embodiment, it becomes possible to promote blue light emission by using the hole transport layer 4 containing a light emitting substance as a light emitting region.

As described above, the hole block layer 33 is for controlling the transport of the holes h. For this purpose, the highest occupied molecular orbital (HOM) of the hole block layer 33 is used.
O) is at or below the highest occupied molecular orbital (HOMO) level of the energetically lower level of the highest occupied molecular orbital (HOMO) level of the hole transporting light emitting layer 4b and the electron transporting layer 2; The lowest unoccupied molecular orbital (LUMO) of the hole transporting light-emitting layer 4b and the electron transporting layer 2 has the lowest unoccupied molecular orbital (LUMO) of 33.
MO) or higher, and not higher than the lowest energy occupied lowest unoccupied molecular orbital (LUMO) level.
It is not limited to the above configuration.

The hole block layer 33 can be formed of various materials, and its thickness may be changed within a range capable of maintaining its function. Its thickness is 1mm ~
The thickness is preferably set to 1000 ° (0.1 nm to 100 nm). If the thickness is too small, the hole blocking ability is incomplete and the recombination region is likely to straddle the hole transport layer and the electron transport layer. Light may not be emitted due to an increase in resistance.

In the green light emitting element portion 21G, since the hole blocking layer 33 is not provided, holes enter the electron transport layer 2 and electron-hole recombination occurs in the electron transport layer 2. The electron transport layer 2 emits light and emits light of a specific wavelength (green) as shown in FIG.

In the red light emitting element portion 21R, since the red light emitting layer 32 is provided instead of the hole blocking layer 33, holes enter the light emitting layer 32, and electron-hole recombination is caused by the light emitting layer. 26, the light emitting layer 32 emits light and emits light of a specific wavelength (red) as shown in FIG.

The above-mentioned organic EL element 21 is manufactured by using a vacuum evaporation apparatus 11 as shown in FIG. Inside the device is a pair of support means 1 fixed below the arm 12.
A stage mechanism (not shown) that allows the transparent glass substrate 6 to face downward and sets the mask 22 is provided between the two fixing means 13 and 13.
The shutter 14 supported by the support shaft 14a is arranged below the glass substrate 6 and the mask 22, and a predetermined number of various evaporation sources 28 are arranged below the shutter 14. Each evaporation source is heated by a power supply 29 by a resistance heating method. For this heating, an EB (electron beam) heating method or the like is used as necessary.

In the above-described apparatus, the mask 22 is for a pixel, and the shutter 14 is for a vapor deposition material. And
The shutter 14 rotates around the support shaft 14a, and shuts off the vapor flow of the material according to the sublimation temperature of the vapor deposition material.

In practice, three types of masks 22 are used, as shown in FIG. 17, and various types of film are formed in a predetermined pattern by appropriately changing them. After the above-described hole transport layer 4 is commonly formed on each element portion through the large opening 23a using the mask 22a, the hole blocking layer 33 is formed using the mask 22b through the slit-shaped opening 23b. 21B is formed in a predetermined pattern, and then the red light emitting layer 32 is formed in a predetermined pattern in the red light emitting element portion 21R through the slit-like opening 23c using the mask 22c.
2a, the electron transport layer 2 is formed in the large aperture 2
The cathode electrode 1 is formed in a predetermined pattern on each element using a mask (not shown).

Thus, as shown in FIG. 17, each light emitting element portion 21 B, 2
1G and 21R are formed in stripes. In addition, these stripes are insulating layers (not shown here).
Is divided into each light emitting area. in this way,
When the respective light emitting element portions are formed in the same pattern on the transparent electrode 5 in a stacked manner, the carrier transportability between the cathode and the anode is improved, and the voltage drop between the two electrodes can be reduced.

FIG. 1 and FIG. 2 are views showing specific examples of the organic EL element 21 manufactured by the above-described vacuum deposition apparatus.
That is, after the ITO transparent electrode 5 serving as a line electrode is deposited on the glass substrate 6 by the above-described vacuum deposition apparatus, SiO ₂ 24 is deposited in a predetermined pattern along the column direction, and the transparent electrode 5 is placed between the SiO _2. Each is exposed to a pixel pattern. Next, using an evaporation mask, each organic layer 4a,
4b, 33, 32, 2 and a metal electrode 1 as a column electrode
(For example, a laminated body of the LiF layer 1a and the Al layer 1b) is sequentially formed in a stripe pattern in the column direction to form a matrix. The above-described deposition masks 22a, 22b, 22
c is used for forming the organic layers 4, 2, 33 and 32. In addition,
Although the organic layers 33 and 32 are formed on the transparent electrode 5 in the line direction, they may be formed in the column direction orthogonal to the transparent electrode 5.

According to the organic EL element 21, in each light emitting element portion, the light emitting region is formed by the hole transport layer 4 (4a, 4a).
b) and the electron transport layer 2 (32) are each independently present,
Since the hole transport layer 4 (4a, 4b) and the electron transport layer 2 are formed of a common material layer between the respective light emitting element portions, a striped laminate (matrix) exhibiting each color of light can be easily formed. It can be manufactured easily and at low cost by the process. Moreover, the organic layers 4a, 4b,
Since No. 2 is formed, the film formability including the portion on the insulating layer 24 is improved, the leakage current between the cathode and the anode is small, and stable and reliable performance can be obtained. this is,
If the upper surface of the insulating layer 24 is curved as shown by a broken line in FIG.

In the above-described vacuum vapor deposition apparatus 11, in addition to the above-described one having pixels as shown in FIGS. 1 and 2, the shape and size can be changed, and a large number of small pixels can be individually or large. Can be formed alone.

The transparent electrode, the organic hole transport layer, the organic hole blocking layer, the red light emitting layer, the organic electron transport layer and the metal electrode of the electroluminescent device may have a laminated structure composed of a plurality of layers.

Each organic layer in the above-mentioned electroluminescent device may be formed by other film formation methods involving sublimation or vaporization, or methods such as spin coating and casting, in addition to vacuum evaporation.

The hole transporting light emitting layer of the above-mentioned electroluminescent device may be subjected to co-evaporation of trace molecules to control the emission spectrum of the device. For example, organic materials such as perylene derivatives and coumarin derivatives may be used. May be an organic thin film containing a trace amount of

The above-mentioned electroluminescent device is suitable for light emission of three colors of R, G and B, but other light-emitting colors can be obtained depending on the kind of light-emitting material used.

Materials usable as the hole transporting material include benzidine or its derivative, styrylamine or its derivative, triphenylmethane or its derivative, porphyrin or its derivative, triazole or its derivative, imidazole or its derivative. , Oxadiazole or its derivative, polyarylalkane or its derivative, phenylenediamine or its derivative, arylamine or its derivative, oxazole or its derivative, anthracene or its derivative, fluorenone or its derivative, hydrazone or its derivative, stilbene or its derivative Derivatives, and heterocyclic conjugated monomers, oligomers, polymers, and the like such as polysilane compounds, vinylcarbazole compounds, thiophene compounds, and aniline compounds are given.

Specifically, α-naphthylphenyldiamine, porphyrin, metal tetraphenylporphyrin,
Metal naphthalocyanine, 4,4 ′, 4 ″ -trimethyltriphenylamine, 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine, N,
N, N ', N'-tetrakis (p-tolyl) p-phenylenediamine, N, N, N', N'-tetraphenyl-
4,4′-diaminobiphenyl, N-phenylcarbazole, 4-di-p-tolylaminostilbene, poly (paraphenylenevinylene), poly (thiophenvinylene), poly (2,2′-thienylpyrrole) and the like. However, the present invention is not limited to these.

Examples of the material usable as the electron transporting material include quinoline or a derivative thereof, perylene or a derivative thereof, bisstyryl or a derivative thereof, and pyrazine or a derivative thereof.

Specifically, there may be mentioned 8-hydroxyquinoline aluminum, anthracene, naphthalene, phenanthrene, pyrene, chrysene, perylene, butadiene, coumarin, acridine, stilbene and derivatives thereof.

The red light emitting material is BSB-
In addition to BCN, DCM, DCM2,
Nile Red, phenoxazine and the like may be used.

The materials used for the anode electrode, cathode electrode and the like of the electroluminescent device are not limited.

As for the cathode electrode material, in order to inject electrons efficiently, it is preferable to use a metal having a small work function from the vacuum level of the electrode material.
In addition to the lithium alloy, for example, a low work function metal such as aluminum, indium, magnesium, silver, calcium, barium, and lithium may be used alone or as an alloy with another metal with increased stability.

Further, in order to extract organic electroluminescence from the anode electrode side, ITO which is a transparent electrode was used for the anode electrode in the later-described embodiment. However, in order to efficiently inject holes, the vacuum level of the anode electrode material was reduced. Alternatively, an electrode having a large work function, for example, gold, tin dioxide-antimony mixture, or zinc oxide-aluminum mixture may be used.

Further, by selecting a light emitting material,
A full-color or multi-color organic electroluminescent element that emits three colors of R, G, and B can be manufactured.
In addition, the present invention can be applied to an organic electroluminescent device that can be used not only for a display but also for a light source, and can also be applied to other optical uses.

The above-mentioned organic electroluminescent device may be sealed with germanium oxide or the like in order to enhance the stability to eliminate the influence of oxygen or the like in the atmosphere, or may be evacuated under vacuum. The element may be driven.

<Second Embodiment> FIG. 24 is a schematic sectional view showing a main part of a blue light emitting element section 21B according to a second embodiment of the present invention.

In the organic EL device according to the present embodiment, the hole transporting light emitting layer 4b is formed on the ITO transparent electrode 5 and the hole transporting light emitting layer is formed as a single layer as compared with the device of FIG. Is different. The other green light emitting element portion 21G and red light emitting element portion 21R are the same as the elements in FIG.

<Third Embodiment> FIG. 25 is a schematic sectional view showing a main part of a blue light emitting element portion 21B according to a third embodiment of the present invention.

In the organic EL device according to the present embodiment, a hole transporting layer (also serving as a hole transporting light emitting layer) 4a is formed on the ITO transparent electrode 5 as compared with the device shown in FIG. The hole transporting light emitting layer is formed as a single layer as in the embodiment. Other than that, it is the same as the above-described second embodiment.

[0100]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 A specific structure of the organic EL device 21 according to the present example will be described based on a manufacturing method thereof.

First, 30 mm × 36 mm, 12 sets of R,
To make a simple matrix of G and B stripes,
A glass substrate 6 of 53 mm × 53 mm has a thickness of about 10
A 0 nm ITO transparent electrode 5 is 1.15 mm wide with an interval of 0.1 mm.
Thirty-six layers were formed at 1 mm, and thirty-one insulating layers 24 were formed on the column side by vacuum evaporation of SiO ₂ at a width of 0.5 mm and an interval of 1.0 mm. Therefore, the light-emitting area of one cell for manufacturing an organic electroluminescent element was 1.0 mm × 1.15 mm, and the aperture ratio was 60.8%.

Then, a mask 22a having an opening 23a having an area of 40.0 mm × 48.0 mm is formed on the ITO transparent electrode 5, and m-MTDATA (4) is formed as a hole transport layer 4 a entirely including the ITO electrode 5. , 4 ', 4 "-tris
(3-methylphenylphenylamino) triphenylamine: Fig. 1
8) at a deposition rate of 0.2 to 0.4 nm / sec.
Was deposited under a vacuum to a thickness of 30 nm by a vacuum deposition method.

Next, on this hole transporting layer 4a, an α-NPD (α-naphtylpheph) was formed as a hole transporting light emitting layer 4b.
nyldiamine: of the structural formula in FIG. This is shown in FIG.
The α-PPD in FIG. 20A, the α-TPD in FIG. 20B, and the TPD in FIG. ) Was vacuum-deposited to a thickness of 50 nm (deposition rate: 0.2 to 0.4 nm / sec) to form a hole-transporting layer 4 having a two-layer structure having a light-emitting property.

Next, a stripe-shaped opening 23b having an area of 1.16 mm × 49 mm is formed on the hole transport layer 4.
Is replaced with a mask 22b having 12 electrodes, and the ITO electrode 5
A phenanthroline derivative represented by a general formula shown in FIG. 4, for example, bathocuproine (2,9-dime)
thyl-4,7-diphenyl-1,10-phenanthroline:
The hole blocking layer 3 shown in the structural formula 2 in FIG.
As No. 3, vacuum deposition was performed on the transparent electrode 5 to a thickness of 20 nm (deposition rate: 0.2 to 0.4 nm / sec).

Next, on the hole transport layer 4, an area of 1.1
The stripe-shaped openings 23c of 6 mm × 49 mm
The BSB-BCN (shown by the structural formula in FIG. 23) is replaced with an electron-transporting red light-emitting material in a stripe pattern of 1.15 mm × 48.0 mm, which is a light-emitting region of the ITO electrode 5, by replacing the mask 22c with the present mask. The layer 32 has a thickness of 20 nm on the transparent electrode 5 (a deposition rate of 0.2 to 0.4 nm).
/ sec).

Thereafter, the area of the mask opening 23a becomes 4
Replace it with a mask 22a of 0.0 mm x 48.00 mm,
As the electron transport layer or the electron transport light emitting layer 2, Alq ₃ (8
-Hydroxy quinoline aluminum (of the structural formula in FIG. 21) was vacuum deposited to a thickness of 40 nm.

Next, the area of the opening is 1.16 mm × 49.
mm, and the cathode electrode 1 was replaced with Al-L
i (aluminum-lithium alloy: Li concentration about 1 mol
%) To a thickness of about 0.5 nm, and Al to a thickness of about 200 nm.
The organic EL element 21 corresponding to R, G, and B shown in FIG.

Next, the characteristics of the organic EL device according to this example were measured, and the results are shown.

FIG. 26 is a graph showing the spectral characteristics of the organic EL element 21 according to Example 1 shown in FIG. That is,
In the light-emitting region having bathocuproine functioning as a hole blocking layer, the maximum light-emitting wavelength was 460 nm, and the coordinates on the CIE chromaticity coordinates were (0.155, 0.11), indicating good blue light emission. This was apparently emission from α-NPD from the shape of the emission spectrum. In the light-emitting portion without bathocuproin, light was emitted from the electron-transporting light-emitting material Alq ₃ , and good green light emission with a maximum emission wavelength of 520 nm and CIE (0.33, 0.55) was obtained. In the stripe portion where BSB-BCN was vapor-deposited between α-NPD and Alq ₃ , good red emission having a maximum emission wavelength of 635 nm and CIE (0.60, 0.39) could be obtained.

As shown in FIG. 27, the luminance was 10 at a current density of 500 mA / cm ² in the blue light emitting portion.
000 cd / m ² and a current density of 1 mA / cm 2
The luminous efficiency at the time of ² was 1.2 lm / W. In the green light emitting part, 700 at a current density of 100 mA / cm ² .
0 cd / m ² , and the luminous efficiency at a current density of 1 mA / cm ² was 1.1 lm / W. In the red light emitting part,
5600 cd / m at a current density of 500 mA / cm ^2
2, luminous efficiency at a current density of 1 mA / cm ² was 0.03lm / W.

Further, the organic EL device was manufactured with a duty ratio of 1
/ 100 pulse drive, current density 5500m
When converted to DC drive at A / cm ^2, the peak luminance is 550
It was 00 cd / m ² , and a high-performance, high-brightness blue light-emitting element portion capable of sufficiently withstanding practical use was manufactured.

Example 2 A specific structure of the organic EL device 21 according to the present example will be described based on a manufacturing method thereof.

First, 30 mm × 36 mm, 12 sets of R,
To make a simple matrix of G and B stripes,
A glass substrate 6 of 53 mm × 53 mm has a thickness of about 10
A 0 nm ITO transparent electrode 5 is 1.15 mm wide with an interval of 0.1 mm.
Thirty-six layers were formed at 1 mm, and thirty-one insulating layers 24 were formed on the column side by vacuum evaporation of SiO ₂ at a width of 0.5 mm and an interval of 1.0 mm. Therefore, the light-emitting area of one cell for manufacturing an organic electroluminescent element was 1.0 mm × 1.15 mm, and the aperture ratio was 60.8%.

Then, a mask 22a having an opening 23a having an area of 40.0 mm × 48.0 mm was formed on the ITO transparent electrode 5 and m-MTDATA (4) was formed as a hole transport layer 4a over the entirety including the ITO electrode 5. , 4 ', 4 "-tris
(3-methylphenylphenylamino) triphenylamine: Fig. 1
8) at a deposition rate of 0.2 to 0.4 nm / sec.
Was deposited under a vacuum to a thickness of 30 nm by a vacuum deposition method.

Next, on the hole transport layer 4a, as a hole transporting light emitting layer 4b, an α-NPD (α-naphtyl
nyldiamine: of the structural formula in FIG. This is shown in FIG.
The α-PPD in FIG. 20A, the α-TPD in FIG. 20B, and the TPD in FIG. ) Was vacuum-deposited to a thickness of 50 nm (deposition rate: 0.2 to 0.4 nm / sec) to form a hole-transporting layer 4 having a two-layer structure having a light-emitting property.

Next, a stripe-shaped opening 23b having an area of 1.16 mm × 49 mm is formed on the hole transport layer 4.
Is replaced with a mask 22b having 12 electrodes, and the ITO electrode 5
A phenanthroline derivative represented by a general formula shown in FIG. 4, for example, bathocuproine (2,9-dime)
thyl-4,7-diphenyl-1,10-phenanthroline:
The hole blocking layer 3 shown in the structural formula 2 in FIG.
As No. 3, vacuum deposition was performed on the transparent electrode 5 to a thickness of 20 nm (deposition rate: 0.2 to 0.4 nm / sec).

Next, on the hole transport layer 4, an area of 1.1
The stripe-shaped openings 23c of 6 mm × 49 mm
DCM2 (as shown by the structural formula in FIG. 22) is changed to a stripe pattern of 1.15 mm × 48.0 mm, which is a light emitting area of the ITO electrode 5, by replacing the mask 22c with the present one.
And Alq ₃ (8-hydroxy quinoline aliminum: Fig. 21
And the molar ratio of DCM2 is from 0.5 to 1%.
So that the electron transporting red light emitting material layer 32
On the transparent electrode 5, a thickness of 20 nm (a deposition rate of 0.2 to 0.
(4 nm / sec).

Thereafter, the area of the mask opening 23a becomes 4
Replace it with a mask 22a of 0.0 mm x 48.00 mm,
As the electron transport layer or the electron transport light emitting layer 2, Alq ₃ (8
-Hydroxy quinoline aluminum (of the structural formula in FIG. 21) was vacuum deposited to a thickness of 40 nm.

Next, the area of the opening is 1.16 mm × 49.
mm, and the cathode electrode 1 was replaced with Al-L
i (aluminum-lithium alloy: Li concentration about 1 mol
%) To a thickness of about 0.5 nm, and Al to a thickness of about 200 nm.
The organic EL element 21 corresponding to R, G, and B shown in FIG.

Next, the characteristics of the organic EL device according to this example were measured, and the results are shown.

That is, as in the organic EL device 21 according to the first embodiment, the maximum emission wavelength is 460 nm in the emission region having bathocuproine functioning as a hole blocking layer, and the CI
The coordinates on the E chromaticity coordinates were (0.155, 0.11), and exhibited good blue light emission. This was apparently emission from α-NPD from the shape of the emission spectrum. In the light-emitting portion without bathocuproin, light emission from Alq ₃ which is an electron-transporting light-emitting material was obtained, and the maximum light emission wavelength was 520 nm and CIE (0.33, 0.55).
Good green light emission was obtained. site of stripes by co-evaporation DCM2 and Alq ₃ between alpha-NPD and Alq _3, the maximum emission wavelength 645nm, CIE (0.66,0.
Good red light emission of 34) could be obtained.

The luminance was 10,000 cd / m ² at a current density of 500 mA / cm ² in the blue light emitting portion, and the luminous efficiency at a current density of 1 mA / cm ² was 1.2 lm / W. In a green light emitting portion, the current density is 7000 cd / m ² at a current density of 100 mA / cm ² , and the luminous efficiency at a current density of 1 mA / cm ² is 1.1 l.
m / W. In the red light emitting area, the current density is 250 m
It was 160 cd / m ² at A / cm ² and the luminous efficiency at a current density of 1 mA / cm ² was 0.04 lm / W.

Embodiment 3 An organic EL device according to a third embodiment of the present invention will be described based on a manufacturing method thereof.

In the organic EL device according to this embodiment, the hole transporting layer 4a is not provided, and α is used as the hole transporting light emitting layer 4b.
-NPD (α-naphtyl phenyldiamine: of the structural formula in FIG. 19), which corresponds to α-PPD in FIG.
Α-TPD of 0 (B) or TPD of (C) may be used. )
Example 1 was deposited under vacuum to a thickness of, for example, 50 nm (deposition rate: 0.2 to 0.4 nm / sec) by a vacuum deposition method, and the hole transporting light emitting layer was formed as a single layer. Is the same as

FIG. 28 is a graph showing the spectral characteristics of the organic EL device according to the third embodiment shown in FIG.

In the case of this example, the maximum emission wavelength (absorption peak) was about 460 nm, and the coordinates on the CIE chromaticity coordinates were (0.155, 0.11), indicating good blue light emission. The green light emission and the red light emission were the same as in FIG.

Then, as shown in FIG.
The luminance at 0 mA / cm ² was 1400 cd / m ² .

From the shape of the light emission spectrum, it was clear that the light was emitted from the hole transporting light emitting layer 4b composed of α-NPD at the blue light emitting portion.

Further, as shown in the threshold voltage characteristics of FIG. 30, almost no current flows until the voltage reaches about 5 V, and the current starts flowing gradually after passing 5 V, and rapidly flows after passing 6 V. That is, it indicates that low-voltage driving is possible and threshold voltage characteristics are good.

Embodiment 4 An organic EL device according to a fourth embodiment of the present invention will be described based on a method for manufacturing the same.

In the organic EL device according to the present embodiment, m-MTDATA (4, 4 ′,
4 "-tris (3-methylphenylphenylamino) triphenyla
mine: having a structural formula of FIG. 18) was deposited in a thickness of 50 nm under vacuum by a vacuum deposition method (a deposition rate of 0.2 to 0.4).
nm / sec), and the hole transporting light emitting layer was formed as a single layer in the same manner as in the third embodiment.

FIG. 31 is a graph showing the spectral characteristics of the organic EL device according to Example 4 shown in FIG.

In the case of this example, the maximum emission wavelength (absorption peak) was about 500 nm, and the coordinates on the CIE chromaticity coordinates were (0.26, 0.47), indicating good green light emission. Red light emission was the same as in FIG.

As shown in FIG. 32, in the blue light emitting portion, the luminance at a current density of 110 mA / cm ² is 280 cd / m ^2.
Met.

From the shape of the emission spectrum, m-MTDA
It was clear that the light was emitted from the hole transporting light emitting layer 4a made of TA.

As can be seen from the voltage: luminance characteristics shown in FIG. 33, driving at a low voltage is possible and luminance is good.

As is clear from the above description, in the organic EL devices of Examples 1 to 4 according to the present invention, the hole blocking layer 33 is made of the hole transporting luminescent material 4a and / or 4b.
By providing between the electron transport layer 2 and the electron transport layer 2, the electron-hole recombination in the hole transport layer becomes sufficient, and the hole transport layer 2 can also serve as a light emitting layer, and highly efficient and stable light emission can be obtained.

Further, not only blue light emission as in Examples 1 and 2, but also green light emission as shown in Example 4, further red light emission by doping, and chromaticity adjustment by doping were possible.

Each of the above-described examples shows that it is possible to manufacture an organic EL device capable of obtaining blue luminescence with excellent chromaticity and high luminance even by using existing materials. It is considered that the possibility and time reduction in the above can be realized, and the design guideline of a new light emitting material system and an electron transport material can be shown.

[0141]

As described above, according to the present invention, the hole transport layer and the electron transport layer are formed of a common material layer between the respective laminates in which the light emitting regions are independently provided in the hole transport layer and the electron transport layer. Thus, a laminate exhibiting each of the luminescent colors can be manufactured easily and at low cost by a simple process. In addition, by forming the common layers with a large aperture mask over the entire surface of the organic pixel region, the film formability or the step coverage is improved, and the leakage current between the cathode and the anode can be reduced.

In particular, light emission due to electron-hole recombination can be obtained in the hole transporting organic material (in particular, the hole blocking layer is inserted between the hole transporting light emitting material and the electron transporting layer). Conventional structure)
Even with an organic electroluminescent device in which a hole transport layer is a light-emitting layer, which has been considered to be a difficult structure due to the absence of an electron transporting material having excellent non-light-emitting properties, stable light emission with high luminance and high efficiency is obtained. be able to. In particular, the emission of blue light is remarkable, and is 10000 cd / m ² or more and 1
Even with pulse driving at a duty ratio of / 100, it is possible to obtain a peak luminance of 55000 cd / m ² or more in DC conversion.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view (A) orthogonal to an anode and a cross-sectional view (B) (a line (B)-(B) of FIG. 1 (A)) of a main part of an organic EL element according to an embodiment of the present invention. ).

FIG. 2 is a schematic exploded perspective view of the same organic EL element.

3A and 3B are schematic cross-sectional views of main parts of the organic EL element according to the first embodiment of the present invention, wherein FIG. 3A is a blue light emitting element, FIG. 3B is a green light emitting element, and FIG. It is a red light emitting element section.

FIG. 4 is a view showing a general formula of a phenanthroline derivative which can be used for the hole blocking layer.

FIG. 5 is a drawing showing the structural formula 1 of the phenanthroline derivative.

FIG. 6 is a diagram showing the structural formula 2 of the phenanthroline derivative.

FIG. 7 is a diagram showing the structural formula 3 of the phenanthroline derivative.

FIG. 8 is a diagram showing the structural formula 4 of the phenanthroline derivative.

FIG. 9 is a diagram showing the structural formula 5 of the phenanthroline derivative.

FIG. 10 is a diagram showing the structural formula 6 of the phenanthroline derivative.

FIG. 11 shows a structural formula 7 of the phenanthroline derivative.

FIG. 12 shows a structural formula 8 of the phenanthroline derivative.

FIG. 13 is a drawing showing the structural formula 9 of the phenanthroline derivative.

FIG. 14 shows a structural formula 10 of the phenanthroline derivative.

FIG. 15 is a band model diagram schematically showing a stacked structure of the organic EL element according to the embodiment.

FIG. 16 is a schematic sectional view of a vacuum deposition apparatus used in the embodiment.

FIG. 17 is a schematic plan view of an evaporation mask used in the embodiment and an organic EL element manufactured.

FIG. 18 shows m-MTDATA used in the embodiment.
It is a figure which shows the structural formula of (a hole transporting light emitting material).

FIG. 19 is a diagram showing a structural formula of α-NPD (hole transporting light emitting material) used in the embodiment.

FIG. 20 shows another hole-transporting light-emitting material that can be used in the embodiment, in which (A) is a structural formula of α-PPD,
(B) is a diagram showing a structural formula of α-TPD, and (C) is a diagram showing a structural formula of TPD.

FIG. 21 is a diagram showing a structural formula of Alq ₃ (electron transport material) used in the embodiment.

FIG. 22 is a diagram showing a structural formula of DCM2 (electron transporting light emitting material) used in Examples of the present invention.

FIG. 23 shows BSB-BC used in another embodiment of the present invention.
It is a figure which shows the structural formula of N (electron transporting light emitting material).

FIG. 24 is a schematic sectional view of a main part of an organic EL device according to a second embodiment of the present invention.

FIG. 25 is a schematic sectional view of a main part of an organic EL device according to a third embodiment of the present invention.

FIG. 26 is a graph showing the spectral characteristics of the organic EL device according to the first embodiment of the present invention.

FIG. 27 is a graph showing current-luminance characteristics of the organic EL device according to the first embodiment.

FIG. 28 is a graph showing spectral characteristics of an organic EL device according to another embodiment of the present invention.

FIG. 29 is a graph showing the electric current of an organic EL device according to another embodiment of the present invention;
5 is a graph showing luminance characteristics.

FIG. 30 is a graph showing the voltage of an organic EL device according to another embodiment of the present invention.
5 is a graph showing luminance characteristics.

FIG. 31 is a graph showing spectral characteristics of an organic EL device according to another embodiment of the present invention.

FIG. 32 is a graph showing the current of an organic EL device according to another embodiment of the present invention.
5 is a graph showing luminance characteristics.

FIG. 33 is a graph showing the voltage of an organic EL device according to another embodiment of the present invention.
5 is a graph showing luminance characteristics.

FIG. 34 is a schematic sectional view showing an example of a conventional organic EL element.

FIG. 35 is a schematic sectional view showing an example of another organic EL element.

FIG. 36 is a schematic perspective view showing a specific example of the organic EL element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal electrode (cathode), 2 ... Electron transport layer, 4 ... Hole transport layer, 4a, 4b ... Hole transport light emitting layer, 5 ... IT
O transparent electrode (anode), 6 ... glass substrate, 10, 2
0, 21: Organic EL element, 21R: Red light emitting element section, 2
1G: green light emitting element portion, 21B: blue light emitting element portion, 2
2, 22a, 22b, 22c: evaporation mask, 24: insulating layer, 32: red light emitting layer, 33: hole blocking layer, e ...
Electron, h ... hall

Claims (24)

[Claims] 1. The hole transport layer according to claim 1, wherein the light emitting region has at least three types of organic material laminates independently present in the hole transport layer and the electron transport layer, and these laminates are formed of a common material layer. And an electron transport layer made of a common material layer, and emits at least three colors. 2. The light-emitting region is made of an organic compound, and has at least three kinds of the laminates made of an organic substance including the light-emitting region. In at least one of these laminates, in the hole transporting organic material, The electroluminescent device according to claim 1, wherein blue light emission is obtained by electron-hole recombination. 3. The electroluminescent device according to claim 2, further comprising a hole blocking layer for causing the recombination in the hole transport layer. 4. The electroluminescent device according to claim 3, wherein said hole blocking layer is provided between a hole transport layer and an electron transport layer. 5. The highest occupancy of the highest occupied molecular orbital level of the hole block layer, which is lower in energy among the highest occupied molecular orbital levels of the organic layers stacked on both sides of the hole block layer The electroluminescent device according to claim 3, which is at a molecular orbital level or lower. 6. The lowest unoccupied molecular orbital level of the hole block layer is lower in energy among the lowest unoccupied molecular orbital levels of the organic layers stacked on both sides of the hole block layer. 4. The electroluminescent device according to claim 3, wherein the electroluminescent device is at or above the lowest unoccupied molecular orbital level and is at or below the lowest energy unoccupied molecular orbital level. 7. The electroluminescent device according to claim 3, wherein the light emitting region is made of a hole transporting material for short wavelength light emission, and the hole blocking layer is made of a phenanthroline derivative. 8. The light-emitting region is made of an organic compound, and has at least three kinds of the laminates made of an organic substance containing the light-emitting region. In at least one of these laminates, an electron-transporting organic material is used. The electroluminescent device according to claim 1, wherein green light emission is obtained by recombination of electrons and holes. 9. The light-emitting region is made of an organic compound, and has at least three kinds of the laminates made of an organic substance including the light-emitting region. In at least one of these laminates, an electron-transporting organic material is used. The electroluminescent device according to claim 1, wherein red light emission is obtained by recombination of electrons and holes. 10. A transparent electrode on an optically transparent substrate,
The electroluminescent device according to claim 1, wherein the organic layer and the metal electrode are sequentially laminated. 11. The organic electroluminescent device in which the transparent electrode, the organic layer, and the metal electrode form a matrix pattern on the same substrate.
The electroluminescent device according to 0. 12. The electroluminescent device according to claim 11, which is configured as a device for a color display. 13. The hole transport layer comprising at least three types of organic substance laminates in which a light emitting region is independently present in a hole transport layer and an electron transport layer, and these laminates are formed of a common material layer. And an electron transport layer made of a common material layer, and in producing an electroluminescent element characterized by exhibiting at least three colors of light. Forming a common first electrode on the laminate, forming a common hole transport layer forming material on a region including at least three types of the laminate on the first electrode, and forming each hole transport layer on the first electrode. Forming, on the region including each of the hole transport layers, a step of forming a common electron transport layer forming material on a region including at least three types of the stacked bodies to form each electron transport layer; Each of the above electrons On the feed layer, and forming opposite the respective second electrode of at least three of said laminate to said first electrode, a manufacturing method of an electroluminescent device. 14. The light-emitting region is formed of an organic compound,
The method according to claim 1, wherein at least three kinds of the laminates including the organic substance including the light emitting region are formed, and at least one of the laminates emits blue light by recombination of electrons and holes in the hole transporting organic material. 14. The method for manufacturing an electroluminescent device according to item 13. 15. The method according to claim 14, wherein a hole block layer for causing the recombination is formed in the hole transport layer. 16. The method according to claim 15, wherein the hole blocking layer is provided between the hole transport layer and the electron transport layer. 17. The highest occupation of the highest occupied molecular orbital level of the hole block layer, which is lower in energy among the highest occupied molecular orbital levels of the organic layers stacked on both sides of the hole block layer 16. The method for manufacturing an electroluminescent device according to claim 15, wherein the molecular orbital level is equal to or lower than the molecular orbital level. 18. The lowest unoccupied molecular orbital level of the hole block layer is set to the lower one of the lowest unoccupied molecular orbital levels of the organic layers stacked on both sides of the hole block layer. The method for manufacturing an electroluminescent device according to claim 15, wherein the level is equal to or higher than the lowest unoccupied molecular orbital level and equal to or lower than the lowest energy unoccupied molecular orbital level. 19. The method according to claim 15, wherein the light emitting region is formed of a hole transporting material for short wavelength light emission, and the hole blocking layer is formed of a phenanthroline derivative. 20. The light-emitting region is formed of an organic compound,
The method according to claim 1, wherein at least three kinds of the laminates made of the organic substance including the light emitting region are formed, and at least one of the laminates emits green light by electron-hole recombination in the electron transporting organic material. 14. The method for manufacturing an electroluminescent device according to item 13. 21. The light-emitting region is formed of an organic compound,
At least three kinds of the laminates made of an organic substance including the light emitting region are formed, and at least one of the laminates emits red light by electron-hole recombination in an electron transporting organic material. 14. The method for manufacturing an electroluminescent device according to item 13. 22. A transparent electrode on an optically transparent substrate,
The method according to claim 15, wherein the organic layer and the metal electrode are sequentially laminated. 23. The method according to claim 22, wherein an organic electroluminescent device in which the transparent electrode, the organic layer, and the metal electrode form a matrix pattern on the same substrate is manufactured. 24. The method according to claim 23, wherein an element for a color display is manufactured.