JP2761453B2 - Organic EL element and organic EL panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence device (hereinafter abbreviated as an organic EL device) and an organic electroluminescence panel (hereinafter referred to as an organic EL device).
Panel).

[0002]

2. Description of the Related Art EL devices have high visibility due to self-emission, and have excellent impact resistance because they are completely solid devices. Because of these features, at present,
Various inorganic EL devices using an inorganic compound as a light-emitting material and various organic EL devices using an organic compound (hereinafter, this compound is referred to as an organic light-emitting material) as a light-emitting material have been proposed and attempted to be put to practical use. Have been.

[0003] Among them, the organic EL element can greatly reduce the applied voltage as compared with the inorganic EL element.
Through the development and improvement of materials, development for obtaining higher-performance organic EL devices has been actively promoted. This organic E
The use of the L element as a surface light source has been promoted, but the use of the L element as a pixel of a display device has also been promoted due to the development of elements having various luminescent colors. In a display device using organic EL elements as pixels, a panel (display panel) is formed by two-dimensionally arranging a plurality of organic EL elements on the same plane, and these elements are independently driven to provide a desired display. I do.

The basic structure of an organic EL device is a structure in which an anode, a light emitting layer, and a cathode are sequentially laminated on a substrate, but the positions of the anode and the cathode may be reversed. In order to improve performance, a hole transport layer is provided between the anode and the light emitting layer, an electron injection layer is provided between the cathode and the light emitting layer, or between the cathode and the light emitting layer or between the cathode and the light emitting layer. An adhesive layer may be provided between the light emitting layer and the light emitting layer. The light emitting layer is usually formed of one or more kinds of organic light emitting materials, but may be formed of a mixture of the organic light emitting material and a hole transport material and / or an electron injection material. Further, of the pair of electrodes (anode and cathode) constituting the organic EL element, the electrode located on the light extraction surface (light emission surface) side as the light emitting element improves the light extraction efficiency, It is composed of a transparent or translucent thin film because of its structure as a light emitting element. on the other hand,
The electrode located on the side opposite to the light extraction surface (hereinafter, referred to as a counter electrode) is formed of a specific metal thin film (a thin film of a metal, alloy, mixed metal, or the like).

[0005]

However, a metal thin film conventionally used as a counter electrode has a high reflectance of visible light, and can be externally applied to the organic EL element regardless of whether the organic EL element emits light or not. A part of the light incident on the surface is reflected by the counter electrode and emitted from the light extraction surface. For this reason, the contrast of the conventional organic EL element and the contrast of the conventional organic EL panel formed by two-dimensionally arranging the elements on the same plane are relatively low. An object of the present invention is to provide an organic EL element having a high contrast and an organic EL panel having a high contrast.

[0006]

In order to achieve the above object, the present invention provides an organic EL device in which an organic single layer portion or an organic multilayer portion containing an organic luminescent material is sandwiched between a pair of electrodes. An organic EL that emits light by applying a predetermined voltage or current between the electrodes.
An element, wherein a polarizing layer is provided outside an electrode located on a light extraction surface side of the pair of electrodes. In addition, the organic E of the present invention that achieves the above object
The L panel is characterized in that the above-described organic EL elements of the present invention are two-dimensionally arranged on the same plane.

Hereinafter, the present invention will be described in detail. First, the organic EL element of the present invention will be described. This organic EL element is an organic EL element having a polarizing layer provided at a specific position as described above, and is a constituent member other than the polarizing layer. The pair of electrodes and the organic single layer portion or the organic multilayer portion sandwiched between the pair of electrodes are the same as those of the conventional organic EL device.

Here, the “organic single layer portion” is substantially 1
Functions as a light-emitting layer of an organic EL device, such as a layer made of only one or more kinds of organic light-emitting materials, or a layer made of a mixture of one or more kinds of organic light-emitting materials and a hole transport material and / or an electron injection material. Means a single-layer structure. The “organic multilayer part” means a laminated structure of two or more layers having a hole transport layer, an electron injection layer, or an adhesive layer in addition to the light emitting layer, and the layers are laminated on the anode in the same manner as in the related art. It is appropriately selected depending on whether the organic multilayer portion is formed or the organic multilayer portion is formed on the cathode.

The constituent materials of the organic single layer portion and the organic multilayer portion are not particularly limited, and have conventionally been used as organic light emitting materials, hole transport materials, electron injection materials, and adhesive layer materials for organic EL devices. Substances can be used as they are. In addition, an inorganic semiconductor is also used as a hole transport material and an electron injection material for an organic EL device, and the inorganic semiconductor is also used as a hole transport material and / or an electron injection material in the organic EL device of the present invention. Can be. Therefore, the organic single-layer portion also includes a layer made of a mixture of a hole transporting material and / or an electron injecting material made of an inorganic semiconductor and one or more kinds of organic light-emitting materials, and the organic multilayer portion contains an inorganic semiconductor. And those having a hole transporting layer and / or an electron injecting layer.

The material of one electrode (anode and cathode) sandwiching the above-described organic single layer portion or organic multilayer portion is not particularly limited, and has conventionally been used as an anode material and a cathode material for an organic EL device. What is being used can be used as it is. For example, as the anode material, a metal, an alloy, an electrically conductive compound, or a mixture thereof having a large work function (4 eV or more) can be used, and specific examples thereof include a metal such as Au, CuI,
A dielectric transparent material such as TO, SnO ₂ , ZnO and the like can be used. As a cathode material, the work function is small (4e
V or less) Metals, alloys, electrically conductive compounds, or mixtures thereof can be used, and specific examples include sodium, sodium-potassium alloys, magnesium, lithium, alloys or mixed metals of magnesium and silver, A
1 / AlO ₂ , indium, rare earth metals and the like.

Incidentally, even if the anode materials described above are used,
By selecting two kinds of substances so that the work function of the anode is relatively larger than the work function of the cathode, the material can be used as the anode and the cathode of the organic EL element in some cases (for example, Au is used as the anode). The size of the work function used as a reference when selecting the cathode material (ITO), the anode material, and the cathode material is not limited to 4 eV.

The sheet resistance of both the anode and the cathode is preferably several hundreds Ω / □ or less. Among the anode and the cathode, the electrode located on the light extraction surface side
It is preferable to select the material and the film thickness so that the light transmittance in the wavelength range of 00 to 600 nm is 10% or more. If the light transmittance is less than 10%, it is difficult to obtain an organic EL element having practically sufficient luminance. The electrode having a light transmittance of 10% or more is, for example, ITO, S
A thickness of 10 to 5 made of a transparent electrode material such as nO ₂ or ZnO.
It can be formed of a 0 μm film or a metal film having a thickness of 1 to 30 μm. In the present invention, 400 to 600 n
The light transmittance in the wavelength range of m means the lowest value of the spectral transmittance of light belonging to the wavelength range among the light emitted from the organic light emitting material.

When the opposite electrode (the electrode located on the side opposite to the light extraction surface) is used as a cathode, 400 to 600
It is particularly preferable to form a metal (including alloy and mixed metal) film having a reflectance of 50% or more in a wavelength region of nm. Such a metal film is excellent in injecting electric charge, particularly electrons, and thus is suitable for improving the light emitting characteristics of the device. The reflectance in the wavelength range of 400 to 600 nm referred to in the present invention means the lowest value of the spectral reflectance of light belonging to the wavelength range among the light emitted from the organic light emitting material.

As described above, the organic EL device of the present invention is characterized in that the polarizing layer is provided outside the electrode located on the light extraction surface side. The polarizing method in this polarizing layer is not particularly limited, birefringence, reflection,
Any of scattering, dichroism and the like may be used. Further, the polarizing layer may be formed of one polarizing plate or polarizing film, or may have a multilayer structure in which a plurality of polarizing plates or polarizing films are combined. However, the light transmittance of the polarizing layer is preferably 30% or more in the wavelength range of 400 to 600 nm. If the light transmittance is less than 30%, it is difficult to obtain an organic EL element having practically sufficient luminance.

A preferred example of the polarizing layer is a combination of a plurality of dichroic polarizing films.
Examples of the dichroic polarizing film include a polyhalogen polarizing film in which iodine is arranged along a molecular chain on a uniaxially oriented film of PVA (polyvinyl alcohol), and a polyhalogenated film on a uniaxially oriented film of PVA along a molecular chain. Dye polarizing film comprising dichroic dyes arranged, PVA
The metal (A
(u, Ag, Hg, Fe, etc.). As a particularly preferred example of the polarizing layer, a linear polarizing plate or a linear polarizing film such as a polarizing film in which iodine or a dye is arranged on a uniaxially oriented film of PVA (for example, Varilite manufactured by Sanritsu Electric Co., Ltd.) A combination with a compensating plate or a retardation compensating film may be used.

Specific examples of commercially available polarizing films or polarizing plates include NPF series (NPF-1000, NPF-1008, NPF) manufactured by Nitto Electric Industry Co., Ltd.
-3000, NPF-4000, NPF-5160
And the like, and Varilite (L-11-8, manufactured by Sanritsu Electric Co., Ltd.)
L-12-18, L-13-18, L-81-18, L
-82-18, L-83-18, etc.), HN type series (HN-7, HN-2) manufactured by Nippon Polaroid Co., Ltd.
2, HN-32, HN-38, HN-42, HNCP-
37, HN-42 ccp, etc.).

The above-described polarizing layer may be provided outside the electrode located on the light extraction surface side of the anode and the cathode. Here, an organic EL element is usually formed by sequentially laminating an anode, an organic single layer portion or an organic multilayer portion, and a cathode (counter electrode) on a transparent substrate, and the transparent substrate on the side opposite to the surface on which the anode and the like are laminated. In many cases, the surface (hereinafter, this surface is referred to as the outer surface of the transparent substrate, and the surface on which the anode and the like are laminated is referred to as the inner surface of the transparent substrate) is used as the light extraction surface. A single layer portion or an organic multilayer portion and an anode may be sequentially laminated, and the anode side may be used as a light extraction surface. The configuration of the organic EL device of the present invention excluding the polarizing layer may be a configuration in which the outer surface of the transparent substrate described above is used as a light extraction surface, or may be stacked on an organic single layer portion or an organic multilayer portion. A configuration may be adopted in which the light-exiting surface is the anode side that has been set.

Therefore, the position of the polarizing layer in the organic EL device of the present invention is such that, when the configuration of the organic EL device is such that the outer surface of the transparent substrate is a light extraction surface, FIG. On the outer surface of the transparent substrate as shown in FIG. 1B, or on the inner surface of the transparent substrate as shown in FIG. Here, in the organic EL device 10a of the present invention shown in FIG. 1A, the anode 2, the organic single layer portion or the organic multilayer portion 3, and the cathode (counter electrode) 4 are sequentially laminated on the inner surface of the transparent substrate 1. And a polarizing layer 5 on the outer surface of the transparent substrate 1.
Is provided. On the other hand, in the organic EL device 10b of the present invention shown in FIG. 1B, the polarizing layer 5, the anode 2, the organic single layer portion or the organic multilayer portion 3, the cathode (counter electrode) 4 Are sequentially laminated. In the case where the configuration of the organic EL element of the present invention is such that the anode side stacked on the organic single layer portion or the organic multilayer portion is a light extraction surface, a polarizing layer is provided on the anode. When a polarizing layer is provided on the outer surface or inner surface of the transparent substrate, the light transmittance of the member having the polarizing layer provided on the transparent substrate surface is 400%.
It is preferable to select the materials of the transparent substrate and the polarizing layer so that the ratio is 10% or more in a wavelength range of from 600 nm to 600 nm.

The organic EL device of the present invention having the above-described structure has a conventional organic EL device except that a polarizing layer is provided at a predetermined position.
Like the L element, it can be manufactured by using a resistance heating evaporation method, an electron beam evaporation method, a sputtering method, a casting method, a spin coating method, or the like. If an evaporation method is used, an electrode (anode and cathode) and an organic single layer portion or an organic multilayer portion can be formed only by this evaporation method, which is advantageous in simplifying equipment and reducing production time. . Also,
As a method for providing the polarizing layer at a predetermined position, there is a method of fixing the material of the polarizing layer at a predetermined position with an adhesive or the like. The structure of the organic EL device of the present invention
When the outer surface of the transparent substrate is used as a light extraction surface, an anode, an organic single layer portion, or an organic multilayer is provided on a predetermined surface (including the polarizing layer surface) of the transparent substrate on which a polarizing layer has been provided in advance. Part and a cathode (counter electrode) may be sequentially laminated, or a polarizing layer is provided on the outer surface of a transparent substrate on which an organic single layer part or an organic multilayer part and a cathode (counter electrode) are sequentially laminated in advance. You may.

A metal (including alloy and mixed metal) film having a reflectance of 50% or more in a wavelength region of 400 to 600 nm is used as the counter electrode (electrode located on the side opposite to the light extraction surface). In the case of using such a metal film, it is necessary to form the film at a vacuum of at least 10 ⁻² Pa or less in order to obtain such a metal film. Further, the organic EL element of the present invention may be one which has been aged by applying a voltage between the anode and the cathode. Here, aging refers to a process of removing a region where a leak current is generated by applying a voltage and removing holes and electrons accumulated in the device (see Japanese Patent Application Laid-Open No. 4-1794). . Due to this aging, a stable operation of the organic EL element can be achieved. Aging is not always necessary, but it is desirable to perform aging from the viewpoint of operation stability of the device.

In the organic EL device of the present invention, which can be obtained as described above, the polarizing layer is provided outside the electrode located on the light extraction surface side. At any time, much of the reflected light from the counter electrode is absorbed by the polarizing layer. Therefore, the contrast of the organic EL device of the present invention is high.

Next, the organic EL panel of the present invention will be described. As mentioned above, the organic EL panel of the present invention
The present invention is characterized in that the above-mentioned organic EL elements of the present invention are two-dimensionally arranged on the same plane. Here, a specific example of the two-dimensional array includes an XY matrix type array. In this case, the organic E belonging to the same row or column
The L element shares one electrode / anode / cathode conductor, and the anode / cathode conductor is provided in such a way that the overall shape thereof when viewed in plan shows a lattice shape. Further, the above-described organic EL element of the present invention is formed at the intersection of the anode / lead wire and the cathode / lead wire in plan view.
The polarizing layer may be provided independently for all the organic EL elements constituting the panel.
It is simpler to provide only one large-sized polarizing layer shared by the elements.

An organic EL panel of a type in which the organic EL elements having the configuration shown in FIG. 1A are two-dimensionally arranged in an XY matrix type is, for example, a method in which a conductive line serving as an anode is formed in a stripe shape on a transparent substrate. The organic single-layer part or the organic multilayer part is provided on the anode / electrode conductor (including the transparent electrode surface not covered by the anode / electrode conductor). After providing a desired number of cathode-conducting conductors in a stripe shape in a direction perpendicular to the anode-conducting conductor in parallel, a large polarizing layer shared by all organic EL elements is provided on the outer surface of the transparent substrate. Can be obtained. The polarizing layer may be provided on a predetermined surface of the transparent substrate before the formation of the anode / lead wire or the like.

An organic EL device having the structure shown in FIG.
An organic EL panel of a type in which elements are two-dimensionally arranged in an XY matrix type has, for example, a large-sized polarizing layer that can be shared by all EL elements provided on a predetermined surface of a transparent substrate. A desired number of anode-conducting wires were provided in parallel in a stripe shape, and an organic single-layer portion or an organic multilayer portion was provided on these anode-cum-conducting wires (including the surface of the polarizing layer not covered by the anode-conducting wire). Thereafter, on the organic single layer portion or the organic multilayer portion, a desired number of cathode-conducting wires can be provided in parallel in a stripe shape in a direction orthogonal to the anode-cum-conducting wires, in parallel.

Further, an organic EL device having a structure in which an anode side stacked on an organic single layer portion or an organic multilayer portion and having an anode side as a light extraction surface is two-dimensionally arranged in an XY matrix type. The panel includes, for example, a desired number of anode conductive wires arranged in a stripe shape in parallel on a transparent substrate, and an organic single layer portion or an organic multilayer portion formed thereon (including the surface of the transparent electrode where the anode dual wire is not provided). Is provided on the organic single layer portion or the organic multi-layer portion in a desired number of parallel lines serving as cathodes in the form of stripes in a direction orthogonal to the anode / lead conductors. (Including the surface of the organic single layer portion or the organic multilayer portion where the conductive wire is not provided) by providing a large polarizing layer shared by all the organic EL elements.

The organic EL panel of the present invention which can be obtained as described above has a high contrast and the visibility of the display pattern because the organic EL element constituting the panel is the above-mentioned organic EL element of the present invention. Excellent.

[0027]

Embodiments of the present invention will be described below. Example 1 (Production of Organic EL Element) A transparent support substrate was prepared by depositing a 100-nm-thick ITO film on a 25 mm × 75 mm × 1.1 mm glass substrate by a vapor deposition method. The light transmittance of this substrate was measured with a UV-3100PC manufactured by Shimadzu Corporation.
It was about 80% in the wavelength range of 00 to 600 nm. This substrate was subjected to ultrasonic cleaning for 5 minutes in isopropyl alcohol and then for 5 minutes in pure water, and further, was subjected to UV ozone cleaning for 10 minutes using an apparatus manufactured by Samco International Laboratories.

Next, the substrate was fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Nippon Vacuum Technology Co., Ltd.), and N, N'-bis (3-methylphenyl-) was added to a molybdenum resistance heating boat. 200 mg of N, N'-diphenyl [1,1'-biphenyl] -4,4'-diamine (hereinafter abbreviated as TPD) was placed in a molybdenum resistance heating boat, and 4,4'-bis ( 2,2'-diphenylvinyl) biphenyl (hereinafter abbreviated as DPVBi)
After adding 00 mg, the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa.

After that, the boat containing the TPD is placed at 215
Up to 220 ° C. to deposit TPD at a deposition rate of 0.1 to 0.1 ° C.
Deposited on the ITO film at 3 nm / s to a film thickness of 60 n
m of the hole transport layer was formed. At this time, the substrate temperature was room temperature. Without removing this from the vacuum chamber, the boat containing DPVBi was placed in the boat for 2 hours after the formation of the hole transport layer.
Heat to 40 ° C. to deposit DPVBi at a deposition rate of 0.1 to 0.1.
The film is deposited on the hole transport layer at 3 nm / s to have a thickness of 40 nm.
A light emitting layer of nm was formed. The substrate temperature at this time was also room temperature.

This was taken out of the vacuum chamber, a stainless steel mask was placed on the light emitting layer, and fixed again to the substrate holder. Next, tris (8-quinolinol) aluminum (hereinafter referred to as Alq ₃
200 mg), 1 g of magnesium ribbon in a different molybdenum boat, and 500 mg of silver wire in a tungsten basket, and these boats were mounted in a vacuum tank.

Then, the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa, and the boat containing Alq ₃ was heated to 230 ° C. to emit Alq ₃ at a deposition rate of 0.01 to 0.03 nm / s. An adhesive layer having a thickness of 20 nm was formed by vapor deposition on the layer. Further, at the same time as depositing silver on the adhesive layer at a deposition rate of 0.1 nm, magnesium was deposited at a deposition rate of 1.
It was deposited on the adhesive layer at 4 nm to form a 150 nm-thick counter electrode made of a mixed metal of magnesium and silver. The reflectance of this counter electrode was measured using UV-3 manufactured by Shimadzu Corporation.
It was 80% in the wavelength region of 400 to 600 nm as measured by 100PC.

Thereafter, a polarizing plate (HN-42 cpp, 400-60 manufactured by Nippon Polaroid Co., Ltd.) is provided on the outer surface of the glass substrate (the surface opposite to the surface on which the ITO film or the like is laminated).
The light transmittance in the wavelength region of 0 nm = 40%) was fixed with an adhesive (araldite manufactured by Ciba Geigy) to obtain a target organic EL device. At this time, the bonding between the glass substrate and the polarizing plate was performed by applying an adhesive to the four side surfaces of the glass substrate and the polarizing plate from the side surface of the glass substrate to the side surface of the polarizing plate. Therefore, the light transmittance of the adhesive has no effect on the light transmittance of the glass substrate.

In the organic EL device thus obtained, an ITO film as an anode is formed on one main surface of a glass substrate.
TPD layer as hole transport layer, DPVB as light emitting layer
An i layer, an Alq ₃ layer as an adhesive layer, and a magnesium-silver mixed metal layer as a counter electrode are sequentially laminated, and a polarizing plate is provided on the outer surface of the glass substrate. This organic EL element is of the type shown in FIG. In this organic EL device, the TPD layer, DP
An organic multilayer part is constituted by the VBi layer and the Alq ₃ layer.

Example 2 (Fabrication of Organic EL Element) AR Filter (Multi) manufactured by Howa Sangyo Co., Ltd. as a polarizing plate
(Light transmittance in the wavelength range of 400 to 600 nm = 55%)
An organic EL device was obtained in the same manner as in Example 1 except that was used.

Example 3 (Preparation of Organic EL Device) As a polarizing plate, HN-38p manufactured by Nippon Polaroid Co., Ltd. was used.
(Light transmittance in a wavelength range of 400 to 600 nm = 30 to 4)
0%), except that organic EL was used.
An element was obtained.

Comparative Example 1 (Preparation of Organic EL Element) An organic EL element was obtained in the same manner as in Example 1 except that no polarizing plate was provided.

Example 4 (Fabrication of Organic EL Device) First, in the same manner as in Example 1 except that the DPVBi layer was not provided, the ITO provided on one main surface of the glass substrate was used.
On the film, a TPD layer, an Alq ₃ layer, and a magnesium-silver mixed metal layer were sequentially laminated. However, the thickness of the Alq ₃ layer was set to 60 nm. The deposition rate of Alq ₃ is 0.01 to 0.02 nm / s, and the initial vacuum pressure of the vacuum chamber when forming the magnesium-silver mixed metal layer is 2 ×.
It was set to 10 ⁻⁴ Pa. Thereafter, the same polarizing plate as in Example 1 was provided on the outer surface of the glass substrate in the same manner as in Example 1 to obtain a target organic EL device.

[0038] Such an organic EL element obtained in the, ITO film, TPD layer and magnesium - as with each silver mixed metal layer Example 1 anode acts as a hole transporting layer and the counter electrode, Alq ₃ The layer functions not as an adhesive layer but as a light emitting layer. This organic EL element is of the type shown in FIG. 1A similarly to the organic EL element of Example 1, and in this organic EL element, the TPD layer and the A
organic multilayer portion is constituted by lq ₃ layers. In addition,
The reflectance of the above-described magnesium-silver mixed metal layer was measured in Example 1.
As a result, it was 78% in the wavelength region of 400 to 600 nm.

Example 5 (Preparation of Organic EL Element) As a polarizing plate, the same AR filter (multi) (400-600 nm) manufactured by Howa Sangyo KK as used in Example 2 was used.
An organic EL device was obtained in the same manner as in Example 4, except that the light transmittance in the wavelength range of 55% was used.

Comparative Example 2 (Preparation of Organic EL Element) An organic EL element was obtained in the same manner as in Example 4 except that no polarizing plate was provided.

Example 6 (Preparation of Organic EL Element) First, the same transparent support substrate as used in Example 1 was prepared, and this substrate was washed in the same manner as in Example 1. next,
While fixing this substrate to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Nippon Vacuum Technology Co., Ltd.), 200 mg of TPD was put into a molybdenum resistance heating boat, and 200 mg of DPVBi was put into a different molybdenum resistance heating boat. Then, 200 mg of Lumogen F Red (red dye manufactured by BASF) was placed in a molybdenum resistance heating boat, and the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa.

Thereafter, the boat containing the TPD is placed in the 215
Up to 220 ° C. to deposit TPD at a deposition rate of 0.1 to 0.1 ° C.
Deposited on the ITO film at 3 nm / s to a film thickness of 60 n
m of the hole transport layer was formed. At this time, the substrate temperature was room temperature. Without removing this from the vacuum chamber, the boat containing Lumogen F red is heated to 330 ° C. following the formation of the hole transport layer, and the deposition rate of Lumogen F red is stabilized at 0.01 to 0.03 nm / s. After letting DPVB
The boat containing i was heated, and after confirming that the deposition rate of DPVBi was stabilized at about 0.6 to 0.7 nm / s, the shutter between the deposition source and the substrate was opened, and Lumogen F red-doped DPVBi was opened. A light emitting layer having a thickness of 40 nm was formed on the hole transport layer. The dopant content in this light emitting layer is 2 to 4 mol% with respect to DPVBi.
Met.

This was taken out of the vacuum chamber, a stainless steel mask was placed on the light emitting layer, and fixed again to the substrate holder. Then, the molybdenum boat
The q ₃ placed 200mg, also placed magnesium ribbon 1g in different molybdenum boat, further putting silver wire 500mg in a tungsten basket, equipped with these boats the vacuum chamber.

Next, the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa, and then the boat containing Alq ₃ was heated to deposit Alq ₃ on the light emitting layer at a deposition rate of 0.1 to 0.3 nm / s. By vapor deposition, an adhesive layer having a thickness of 20 nm was formed. Further, at the same time as depositing silver on the adhesive layer at a deposition rate of 0.1 nm, magnesium is deposited on the adhesive layer at a deposition rate of 1.5 nm to form a 150 nm-thick opposing film made of a mixed metal of magnesium and silver. An electrode was formed. When the reflectance of this counter electrode was measured in the same manner as in Example 1, the reflectance was 400
It was 80% in the wavelength range of ６００600 nm. Thereafter, the same polarizing plate as in Example 1 was provided on the outer surface of the glass substrate in the same manner as in Example 1 to obtain a target organic EL device.

In the organic EL device thus obtained, an ITO film as an anode was formed on one main surface of a glass substrate.
TPD layer as a hole transport layer, Lumogen F red doped DPVBi layer as a light emitting layer, Alq ₃ as an adhesive layer
A layer and a magnesium-silver mixed metal layer as a counter electrode are sequentially laminated, and a polarizing plate is provided on the outer surface of the glass substrate. This organic EL element is of the type shown in FIG. 1A similarly to the organic EL element of Example 1. In this organic EL element, an organic multilayer is formed by a TPD layer, a Lumogen F red-doped DPVBi layer and an Alq ₃ layer. Unit is configured.

Example 7 (Preparation of Organic EL Element) As a polarizing plate, the same AR filter (multi) (400 to 600 nm) manufactured by Howa Sangyo KK as used in Example 2 was used.
An organic EL device was obtained in the same manner as in Example 6, except that the light transmittance in the wavelength range of 55% was used.

Comparative Example 3 (Preparation of Organic EL Element) An organic EL element was obtained in the same manner as in Example 6, except that no polarizing plate was provided.

Measurement of contrast

[0049]

(Equation 1) The contrast of each of the organic EL devices produced in Examples 1 to 7 and Comparative Examples 1 to 3 was measured as follows.

First, under normal fluorescent lighting in a laboratory,
The device is placed on a predetermined table with the light-emitting surface facing up, and an incandescent lamp (100
W). Then, while the incandescent lamp is turned on, a luminance when the element emits light by applying a predetermined voltage to the element and a luminance when the voltage is not applied to the element are respectively measured by a color difference meter (manufactured by Minolta Camera Co., Ltd.). CS-100). Then, the contrast was calculated from the measurement results based on the above equation. Note that the optical environment at the time of measuring the luminance simulates a typical optical environment when the organic EL element is actually used. In addition to the measurement of the contrast, the color (light source color) of the light emitted from each organic EL element is measured in the optical environment and the dark room at the time of the luminance measurement according to JIS Z 8724, respectively. The light source color was represented by CIE chromaticity coordinates in the XYZ color system based on Z8701. Table 1 shows the results.

[0051]

[Table 1]

As is clear from Table 1, the contrast of each of the organic EL devices manufactured in Examples 1 to 3 was the same as that of the organic EL devices except that no polarizing plate was provided. It is much higher than the contrast of the organic EL device of Example 1. The same is true between the organic EL devices manufactured in Examples 4 and 5 and the organic EL device of Comparative Example 2, and the organic EL devices manufactured in Examples 6 and 7.
The same can be said between the L element and the organic EL element of Comparative Example 3. Also, as is clear from the CIE chromaticity coordinates of the light source colors measured in the optical environment and the dark room at the time of the luminance measurement, respectively,
In each of the organic EL devices manufactured in Examples 1 to 7, no difference was observed between the luminescent color under the optical environment during the luminance measurement and the luminescent color in the dark room, and the optical characteristics during the luminance measurement were not changed. The emission color was clear even under the environment. On the other hand, Comparative Examples 1 to 3
Each of the organic EL devices prepared in the above has a difference between the luminescent color in the optical environment at the time of measuring the luminance and the luminescent color in the dark room. Is declining.

Example 8 (Fabrication of Organic EL Panel) First, a 10 mm × 40 mm × 100 nm ITO film formed of an ITO film was formed on one main surface of a 40 mm × 40 mm × 1.1 mm glass substrate in stripes at intervals of 2 mm. 3
This was provided as a transparent support substrate, and this substrate was washed in the same manner as in Example 1. Next, a TPD layer as a hole transport layer and a DPVBi layer as a light emitting layer were formed on the surface of the glass substrate on the side provided with the anode / lead wire made of the ITO film and on the anode / lead wire in the same manner as in Example 1. They were sequentially laminated. Next, this was taken out from the vacuum chamber, a predetermined stainless steel mask was placed on the light emitting layer, and the substrate was fixed to the substrate holder again.

Thereafter, an Alq ₃ layer as an adhesive layer was laminated in the same manner as in Example 1, and a magnesium-silver mixed metal layer as a cathode / lead wire was formed on this Alq ₃ layer in the same manner as in Example 1. Laminated. At this time, the Alq ₃ layer is provided in the form of three stripes orthogonal to the anode conductive wire (ITO film) in plan view by using the stainless steel mask.
The width of the book is 10 mm, its length in plan view is 40 mm, and the interval between adjacent stripes is 2 mm. The magnesium-silver mixed metal layer (cathode-conducting wire) laminated on the Alq ₃ layer also has an underlying Alq
_{It has the} same shape as the _three layers in plan view. The three anode / lead conductors (ITO film) and three cathode / lead wires (magnesium-silver mixed metal layer) have a lattice shape when viewed in plan. Then, on the outer surface of the glass substrate, the same polarizing plate as used in Example 1 (size: length × width = 40 mm × 4)
0 mm) was fixed in the same manner as in Example 1 to obtain an intended organic EL panel.

FIG. 2 shows a rear view of the organic EL panel. As shown in FIG. 2, in this organic EL panel 20, ITO is formed on one main surface (inner surface) of the glass substrate 21.
Three anode / lead wires 22a, 22b, 22c made of a film
Are provided in the form of stripes, and TP (not shown) is provided on these anode / lead wires 22a, 22b, and 22c.
Three cathode-cum-conducting wires 23 made of a magnesium-silver mixed metal layer via a D layer, a DPVBi layer, and an Alq ₃ layer
a, 23b and 23c are connected to the anode / lead wire 22a, 2
It is provided in a stripe shape in a direction orthogonal to the planes 2b and 22c in plan view. Also, on the outer surface of the glass substrate 21,
A polarizing plate not shown is provided. This organic EL
In the panel 20, the anode / lead wires 22a, 22b, 22c
An organic EL element having the same configuration as that of the organic EL element manufactured in Example 1 is formed at the intersections (a total of nine places) in plan view between the electrodes and the conducting wires 23a, 23b, and 23c.

A voltage of 11 V is applied to the organic EL element 24 formed at the center of the organic EL panel (2 rows and 2 columns on the XY matrix) (see FIG. 2), and the contrast is reduced. 1 was measured in the same manner as in example 7, the contrast was as good as 78 (luminance = 132cd / m ² when a voltage is applied, luminance = 1.7 cd / m ² when no voltage is applied) .

[0057]

As described above, the organic EL of the present invention
The element and the organic EL panel have high contrast. Therefore, according to the present invention, it is possible to provide an organic EL panel with high visibility.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration example of an organic EL device of the present invention.

FIG. 2 is a rear view showing the organic EL panel manufactured in Example 8.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate, 2 ... Anode, 3 ... Organic single layer part or organic multilayer part, 4 ... Cathode (counter electrode), 5 ... Polarizing layer,
10a, 10b, 24: Organic EL element, 20: Organic E
L panel, 21 ... glass substrate, 22a, 22b, 22
c: anode and lead 23a, 23b, 23c: cathode and lead

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-112194 (JP, A) JP-A-6-151061 (JP, A) JP-A-6-283270 (JP, A) JP-A-6-283270 350133 (JP, A) JP-A-6-5367 (JP, A) JP-A-4-2497 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H05B 33/14 H05B 33 / 28

Claims (4)

(57) [Claims] 1. An organic single-layer portion or an organic multilayer portion containing an organic light-emitting material is sandwiched between a pair of electrodes, and the organic light-emitting material is applied by applying a predetermined voltage or current between the pair of electrodes. An organic EL device that emits a material, wherein a polarizing layer is provided outside an electrode of the pair of electrodes located on a light extraction surface side. 2. An electrode located on a light extraction surface side has a light transmittance of 10% or more in a wavelength region of 400 to 600 nm.
The reflectance of the electrode located on the side opposite to the light extraction surface is 50% or more in a wavelength range of 400 to 600 nm.
The organic EL device according to claim 1. 3. The organic EL device according to claim 1, wherein the polarizing layer has a multilayer structure. 4. An organic EL panel, wherein the organic EL elements according to claim 1 are two-dimensionally arranged on the same plane.