WO2014200067A1

WO2014200067A1 - Organic electroluminescent element and electronic device

Info

Publication number: WO2014200067A1
Application number: PCT/JP2014/065618
Authority: WO
Inventors: 有章志田
Original assignee: コニカミノルタ株式会社
Priority date: 2013-06-13
Filing date: 2014-06-12
Publication date: 2014-12-18
Also published as: JPWO2014200067A1

Abstract

This organic electroluminescent element is provided with a first electrode, a first light-emitting functional layer provided on top of the first electrode, a second electrode provided on top of the first light-emitting functional layer, a second light-emitting functional layer provided on top of the second electrode, and a third electrode provided on top of the second light-emitting functional layer. The first and third electrodes have the same polarity, and the polarity of the second electrode is opposite that of the first and third electrodes.

Description

ORGANIC ELECTROLUMINESCENT ELEMENT AND ELECTRONIC DEVICE

The present invention relates to an organic electroluminescence element and an electronic device including the organic electroluminescence element.

An organic electroluminescence element (organic EL element) has advantages such as less viewing angle dependency, a high contrast ratio, and a reduction in thickness as compared with a liquid crystal display device.
In recent years, portable displays and portable rear displays using organic EL elements have been actively put on the market. Display using these organic EL elements is expected to be put on the market for large TVs due to its high visibility, and some plans for launch are reported. Yes.

Further, since the organic EL element is a self-luminous light source and is a surface-emitting light source, it has been spotlighted as next-generation illumination and has been developed in various places as organic EL illumination.
The organic EL element has RGB light emitting materials between the electrodes, and is prepared by arbitrarily adjusting and driving RGB light output, or by applying a layer design including the thickness of the organic layer. The emission color and emission color intensity can be freely changed. For this reason, the organic EL element can emit light freely as a white color required for illumination use, for example, from a light bulb color such as a color temperature of 2000K or 3000K to a daylight white color such as 5000K or 6000K. Furthermore, by using a phosphorescent material, it is possible to realize luminous efficiency equivalent to or exceeding that of LEDs and fluorescent lamps, and realization as thinning illumination is expected.

In addition, in order to change a plurality of colors as in a display, for example, an illumination or a light source that changes the color by forming an RGB light emitting layer in a strip shape in the horizontal direction and changing the intensity ratio of each light emitting color has been proposed (For example, refer to Patent Document 1).
Furthermore, it has also been proposed to increase the aperture ratio by stacking RGB light-emitting layers in a direction perpendicular to a transparent substrate to perform color matching (see, for example, Patent Document 2).

JP 2003-066868 A Special table 2008-503055 gazette

In organic EL lighting, it is necessary to increase the size of the organic EL element and to improve the light emission luminance in order to obtain a lumen required for lighting applications. Further, when the RGB light emitting layer of the organic EL element is formed with a fine pattern as in a display, the aperture ratio is reduced and the luminance is lowered.

In order to compensate for the reduction of the aperture ratio and the decrease in luminance, in the configuration in which each RGB light emitting layer is stacked in a straight line with the substrate to correct the aperture ratio, one electrode is formed between the light emitting layers of each color. It is necessary to function as an anode in one color and as a cathode in the other color. For this reason, when the organic EL element having a stack structure is toned, independent duty driving is required for the light emitting layers of the respective colors. Therefore, the respective colors cannot be emitted at the same time, and the light emission efficiency under actual driving of the organic EL element is lowered.

In order to solve the above-described problems, the present invention provides an organic electroluminescence element and an electronic device capable of improving luminance.

The organic electroluminescence device of the present invention is provided on the first electrode, the first light emitting functional layer provided on the first electrode, the second electrode provided on the first light emitting functional layer, and the second electrode. A second light emitting functional layer, and a third electrode provided on the second light emitting functional layer. The first electrode and the third electrode are electrodes having the same polarity, and the second electrode is an electrode having a polarity opposite to that of the first electrode and the third electrode.

Further, the organic electroluminescence element of the present invention includes a first electrode, a first light emitting functional layer provided on the first electrode, a second electrode provided on the first light emitting functional layer, and a second electrode. A second light emitting functional layer provided on the second electrode, a third light emitting functional layer provided on the second electrode at a position different from the second light emitting functional layer, and on the second light emitting functional layer and the third light emitting functional layer. A third electrode provided. In addition, the first electrode and the third electrode are electrodes having opposite polarities, and the second electrode has an opposite polarity with respect to the first light emitting functional layer, the second light emitting functional layer, and the third light emitting functional layer. It becomes an electrode.

Moreover, an electronic apparatus of the present invention includes the organic electroluminescence element.

According to the organic electroluminescent element of the present invention, the second electrode provided between the first light emitting functional layer and the second light emitting functional layer is the same as the first light emitting functional layer and the second light emitting functional layer. Functions as a polar electrode. For this reason, the first light emitting functional layer and the second light emitting functional layer can be driven simultaneously. Therefore, the brightness of the organic electroluminescence element can be improved.
Moreover, according to the organic electroluminescent element of this invention, the 2nd light emission functional layer and the 3rd light emission functional layer are provided on the 1st light emission functional layer. For this reason, the aperture ratio of the first light emitting functional layer can be configured to be larger than that of the second light emitting functional layer and the third light emitting functional layer, and the luminance of the first light emitting functional layer can be improved. Therefore, the brightness of the organic electroluminescence element can be improved.

According to the present invention, it is possible to provide an organic electroluminescence element and an electronic device capable of improving luminance.

It is a figure which shows schematic structure of the organic EL element of 1st Embodiment. It is a figure which shows the drive waveform of the organic EL element of 1st Embodiment. It is a figure which shows schematic structure of the organic EL element of 2nd Embodiment. It is a figure which shows the drive waveform of the organic EL element of 2nd Embodiment. It is a figure which shows schematic structure of the organic EL element of the modification of 2nd Embodiment. It is a figure which shows schematic structure of the organic EL element of 3rd Embodiment. It is a figure which shows the drive waveform of the organic EL element of 3rd Embodiment.

Examples of the best mode for carrying out the present invention will be described below, but the present invention is not limited to the following examples.
The description will be given in the following order.
1. Organic electroluminescence device (first embodiment)
2. Organic electroluminescence device (second embodiment and modifications)
3. Organic electroluminescence device (third embodiment)

<1. Organic Electroluminescence Element (First Embodiment)>
Specific embodiments of the organic electroluminescence element (hereinafter referred to as organic EL element) of the present invention will be described.

[Configuration of organic electroluminescence element]
In FIG. 1, the schematic block diagram (sectional drawing) of the organic EL element of 1st Embodiment is shown.
The organic EL element shown in FIG. 1 includes a first light emitting unit 18, a second light emitting unit 19, and an insulating layer 17 serving as a partition wall for element separation between the first light emitting unit 18 and the second light emitting unit 19. In addition, an organic EL element having these configurations is mounted on the support substrate 20.

The first light emitting unit 18 has a configuration in which the first electrode 14, the first light emitting functional layer 11, the second electrode 15, the second light emitting functional layer 12, and the third electrode 16 are laminated in this order. The second light emitting unit 19 has a configuration in which the first electrode 14, the first light emitting functional layer 11, the second electrode 15, the third light emitting functional layer 13, and the third electrode 16 are laminated in this order. As described above, the first light emitting unit 18 and the second light emitting unit 19 in which the two light emitting layers are stacked via the electrodes are alternately arranged on the support substrate 20 via the insulating layers 17 serving as partition walls. Yes.

The first electrode 14 is provided independently for each of the first light emitting unit 18 and the second light emitting unit 19 on the support substrate 20. The first electrodes 14 are insulated from each other by an insulating layer 17. Further, the first electrode 14 is connected to a power supply circuit of a driving unit of an organic EL element (not shown).

In the first light emitting unit 18 and the second light emitting unit 19, the first light emitting functional layer 11 is provided on the first electrode 14. The first light emitting functional layer 11 has a configuration that will be described in detail later, and includes at least one organic light emitting layer.

In the first light emitting unit 18 and the second light emitting unit 19, the second electrode 15 is provided on the first light emitting functional layer 11. The second electrode 15 is connected to a power supply circuit of a driving unit (not shown) of the organic EL element, similar to the first electrode 14 described above.

In the first light emitting unit 18, the second light emitting functional layer 12 is provided on the second electrode 15. In the second light emitting unit 19, the third light emitting functional layer 13 is provided on the second electrode 15. Each of the second light emitting functional layer 12 and the third light emitting functional layer 13 includes an organic light emitting layer having an emission color different from that of the first light emitting functional layer 11 described above. That is, in the organic EL element, the first light emitting functional layer 11, the second light emitting functional layer 12, and the third light emitting functional layer 13 have different light emitting layers.

In the first light emitting unit 18, the third electrode 16 is provided on the second light emitting functional layer 12. Similarly, in the second light emitting unit 19, the third electrode 16 is provided on the third light emitting functional layer 13. The third electrode 16 is connected to a power supply circuit of a driving unit (not shown) of the organic EL element, similar to the first electrode 14 described above.

The organic EL element of this example is configured to extract emitted light from the support substrate 20 side. For this reason, the 1st electrode 14 and the 2nd electrode 15 are comprised by the transparent electrode. The support substrate 20 is a transparent substrate.

As described above, the first light emitting unit 18 includes the first light emitting functional layer 11 and the second light emitting functional layer 12. The second light emitting unit 19 includes the first light emitting functional layer 11 and the third light emitting functional layer 13. Therefore, for example, the first light emitting functional layer 11 of the first light emitting unit 18 is configured to have a blue (B) light emitting layer, and the second light emitting functional layer 12 is configured to have a green (G) light emitting layer. . Further, in the second light emitting unit 19, the first light emitting functional layer 11 is configured to have a blue (B) light emitting layer, and the third light emitting functional layer 13 is configured to have a red (R) light emitting layer. As described above, the organic EL element has the first to third light emitting functional layers in the two light emitting units, and thus can emit light of three colors composed of RGB.

In the first light emitting unit 18, the first light emitting functional layer 11 is sandwiched between the first electrode 14 and the second electrode 15. The second light emitting functional layer 12 is sandwiched between the second electrode 15 and the third electrode 16.
In the second light emitting unit 19, the first light emitting functional layer 11 is sandwiched between the first electrode 14 and the second electrode 15. The third light emitting functional layer 13 is sandwiched between the second electrode 15 and the third electrode 16.
That is, the second electrode 15 is configured as a common electrode for the first light emitting functional layer 11 and the second light emitting functional layer 12 and the third light emitting functional layer 13 formed on the second electrode 15. .

In addition, the first electrode 14 and the third electrode 16 are electrodes having the same polarity, and the second electrode 15 is an electrode having a polarity opposite to that of the first electrode 14 and the third electrode 16. For example, the first electrode 14 described above functions as a cathode with respect to the first light emitting functional layer 11. Similarly, the third electrode 16 functions as a cathode with respect to the second light emitting functional layer 12 and the third light emitting functional layer 13 in this example. The second electrode 15 functions as an anode with respect to the first light emitting functional layer 11. Further, the second electrode 15 also functions as an anode for the second light emitting functional layer 12 and the third light emitting functional layer 13 provided on the second electrode 15.

Hereinafter, each configuration of the organic EL element will be described.
[Light emitting functional layer]
The organic EL element has a configuration including a pair of electrodes and a light emitting functional layer having light emitting properties between the electrodes. As typical element structures of the light emitting functional layer, the following structures can be raised, but the invention is not limited to these.
(1) Light emitting layer (2) Light emitting layer / electron transport layer (3) Hole transport layer / light emitting layer (4) Hole transport layer / light emitting layer / electron transport layer (5) Hole transport layer / light emitting layer / electron Transport layer / electron injection layer (6) hole injection layer / hole transport layer / light emitting layer / electron transport layer (7) hole injection layer / hole transport layer / (electron blocking layer /) light emitting layer / (hole Blocking Layer /) Electron Transport Layer / Electron Injection Layer Among the above, the configuration of (7) is preferably used, but is not limited thereto.

In the above structure, the light emitting layer is formed of a single layer or a plurality of layers. When there are a plurality of light emitting layers, a non-light emitting intermediate layer may be provided between the light emitting layers.
If necessary, a hole blocking layer (hole blocking layer), an electron injection layer (cathode buffer layer), or the like may be provided between the light emitting layer and the cathode, and between the light emitting layer and the anode. An electron blocking layer (electron barrier layer), a hole injection layer (anode buffer layer), or the like may be provided.
The electron transport layer is a layer having a function of transporting electrons. The electron transport layer includes an electron injection layer and a hole blocking layer in a broad sense. Further, the electron transport layer may be composed of a plurality of layers.
The hole transport layer is a layer having a function of transporting holes. The hole transport layer includes a hole injection layer and an electron blocking layer in a broad sense. The hole transport layer may be composed of a plurality of layers.

[Light emitting layer]
The light-emitting layer used in the organic EL element is a layer that provides a field in which electrons and holes injected from an electrode or an adjacent layer are recombined to emit light via excitons. In the light emitting layer, the light emitting portion may be within the layer of the light emitting layer or may be the interface between the light emitting layer and the adjacent layer.

The total thickness of the light emitting layer is not particularly limited, and is determined from the viewpoint of the uniformity of the film to be formed, the voltage required for light emission, and the stability of the emission color with respect to the drive current. The total thickness of the light emitting layers is preferably adjusted to a range of 2 nm to 5 μm, for example, more preferably adjusted to a range of 2 nm to 500 nm, and further preferably adjusted to a range of 5 nm to 200 nm. Further, the individual film thickness of the light emitting layer is preferably adjusted to a range of 2 nm to 1 μm, more preferably adjusted to a range of 2 nm to 200 nm, and further preferably adjusted to a range of 3 nm to 150 nm.

The light emitting layer preferably contains a light emitting dopant (a light emitting dopant compound, a dopant compound, also simply referred to as a dopant) and a host compound (a matrix material, a light emitting host compound, also simply referred to as a host).

(1. Luminescent dopant)
As the light-emitting dopant used in the light-emitting layer, a fluorescent light-emitting dopant (also referred to as a fluorescent dopant or a fluorescent compound) and a phosphorescent dopant (also referred to as a phosphorescent dopant or a phosphorescent compound) are preferably used. Of these, at least one light emitting layer preferably contains a phosphorescent dopant.

The concentration of the light emitting dopant in the light emitting layer can be arbitrarily determined based on the specific dopant used and the requirements of the device. The concentration of the optical dopant may be contained at a uniform concentration relative to the thickness direction of the light emitting layer, or may have an arbitrary concentration distribution.

The light emitting layer may contain a plurality of types of light emitting dopants. For example, a combination of dopants having different structures, or a combination of a fluorescent luminescent dopant and a phosphorescent luminescent dopant may be used. Thereby, arbitrary luminescent colors can be obtained.

The color emitted by the organic EL element is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Society for Color Science, University of Tokyo Press, 1985), with a spectral radiance meter CS-2000 (Konica Minolta Sensing ( It is determined by the color when the result measured by (made by Co., Ltd.) is applied to the CIE chromaticity coordinates.

In the organic EL element, it is also preferable that the light emitting layer of one layer or a plurality of layers contains a plurality of light emitting dopants having different light emission colors and emits white light. There are no particular limitations on the combination of light-emitting dopants that exhibit white, but examples include a combination of blue and orange, a combination of blue, green, and red.
As the white color in the organic EL element, the chromaticity in the CIE 1931 color system at 1000 cd / m ² is x = 0.30 ± 0.09, y = It is preferably in the range of 0.30 ± 0.08.

(1-1. Phosphorescent dopant)
The phosphorescent dopant is a compound in which light emission from an excited triplet is observed. Specifically, the phosphorescent dopant is a compound that emits phosphorescence at room temperature (25 ° C.), and has a phosphorescence quantum yield of 0 at 25 ° C. .01 or more compounds. In the phosphorescent dopant used for a light emitting layer, a preferable phosphorescence quantum yield is 0.1 or more.

The phosphorescent quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. The phosphorescence quantum yield in a solution can be measured using various solvents. The phosphorescence emitting dopant used for the light emitting layer should just achieve the said phosphorescence quantum yield (0.01 or more) in any solvent.

There are two types of light emission of the phosphorescent dopant.
First, an excited state of the host compound is generated by recombination of carriers on the host compound to which carriers are transported. It is an energy transfer type in which light is emitted from the phosphorescent dopant by transferring this energy to the phosphorescent dopant. The other is a carrier trap type in which a phosphorescent dopant becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant is obtained. In any case, it is a condition that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.

The phosphorescent dopant can be appropriately selected from known materials used for the light emitting layer of the organic EL element.
Specific examples of known phosphorescent dopants include compounds described in the following documents.

Nature 395,151 (1998), Appl. Phys. Lett. 78, 1622 (2001), Adv. Mater. 19, 739 (2007), Chem. Mater. 17, 3532 (2005), Adv. Mater. 17, 1059 (2005) ), International Publication No. 2009100991, International Publication No. 2008101842, International Publication No. 2003030257, United States Patent Publication No. 2006835469, United States Patent Publication No. 20060202194, United States Patent Publication No. 20070087321, and United States Patent Publication No. 20050246673.

Inorg. Chem. 40, 1704 (2001), Chem. Mater. 16, 2480 (2004), Adv. Mater. 16, 2003 (2004), Angew. Chem. Lnt. Ed. 2006, 45, 7800, Appl. Phys Lett. 86, 153505 (2005), Chem. Lett. 34, 592 (2005), Chem. Commun. 2906 (2005), Inorg. Chem. 42, 1248 (2003), International Publication No. 20090290290, International Publication No. 2002015645, International Publication No. 2009000673, U.S. Patent Publication No. 20020034656, U.S. Patent No. 7332232, U.S. Patent Publication No. 20090108737, U.S. Patent Publication No. 20090039776, U.S. Patent No. 6921915, U.S. Pat. US Patent Publication No. 20070190359, US Patent Publication No. 20060860570, US Patent Publication No. 20090165846, US Patent Publication No. 20080015355, US Patent No. 7250226, U.S. Patent No. 7396598, U.S. Patent Publication No. 20060263635, U.S. Patent Publication No. 20030138657, U.S. Patent Publication No. 20030152802, U.S. Patent No. 7090928

Angew. Chem. Lnt. Ed. 47, 1 (2008), Chem. Mater. 18, 5119 (2006), Inorg. Chem. 46, 4308 (2007), Organometallics 23, 3745 (2004), Appl. Phys. Lett 74, 1361 (1999), International Publication No. 2002002714, International Publication No. 2006009024, International Publication No. 200606056418, International Publication No. 2005019373, International Publication No. 200500513833, International Publication No. 200500513873, International Publication No. 2007004380, International Patent Publication No. 2006082742, United States Patent Publication No. 20060251923, United States Patent Publication No. 20050260441, United States Patent No. 7393599, United States Patent No. 7,534,505, United States Patent No. 7,445,855, United States Patent Publication No. 20070190359, United States Patent Publication No. 20080297033. No., US Pat. No. 73387 2, U.S. Patent Publication No. 20020134984, U.S. Pat. No. 7,279,704, U.S. Patent Publication No. 2006098120, US Patent Publication No. 2006103874

International Publication No. 2005076380, International Publication No. 20130032663, International Publication No. 2008140115, International Publication No. 20077052431, International Publication No. 20111134013, International Publication No. 2011157339, International Publication No. 20100086089, International Publication No. 20101313646, International Publication No. 2012020327, International Publication No. 20111051404, International Publication No. 2011004639, International Publication No. 20111073149, U.S. Patent Publication No. 20122228583, U.S. Patent Publication No. 201212212126, JP2012-0697737A, JP2012-195554A. JP, 2009-114086, JP 2003-81988, JP 2002-302671, JP 200 -363,552 JP

Among them, a preferable phosphorescent dopant is an organometallic complex having Ir as a central metal. More preferably, a complex containing at least one coordination mode of a metal-carbon bond, a metal-nitrogen bond, a metal-oxygen bond, and a metal-sulfur bond is preferable.

Hereinafter, specific examples of known phosphorescent dopants applicable to the light emitting layer will be given, but the phosphorescent dopant is not limited thereto, and other compounds can also be applied.

(1-2. Fluorescent luminescent dopant)
The fluorescent light-emitting dopant is a compound that can emit light from an excited singlet, and is not particularly limited as long as light emission from the excited singlet is observed.

Examples of the fluorescent light-emitting dopant include anthracene derivatives, pyrene derivatives, chrysene derivatives, fluoranthene derivatives, perylene derivatives, fluorene derivatives, arylacetylene derivatives, styrylarylene derivatives, styrylamine derivatives, arylamine derivatives, boron complexes, coumarin derivatives, Examples include pyran derivatives, cyanine derivatives, croconium derivatives, squalium derivatives, oxobenzanthracene derivatives, fluorescein derivatives, rhodamine derivatives, pyrylium derivatives, perylene derivatives, polythiophene derivatives, rare earth complex compounds, and the like.

In addition, a light emitting dopant using delayed fluorescence may be used as the fluorescent light emitting dopant.
Specific examples of the luminescent dopant using delayed fluorescence include compounds described in, for example, International Publication No. 2011/156793, Japanese Patent Application Laid-Open No. 2011-213643, Japanese Patent Application Laid-Open No. 2010-93181, and the like.

(2. Host compound)
The host compound is a compound mainly responsible for charge injection and transport in the light emitting layer, and its own light emission is not substantially observed in the organic EL element.
Preferably, it is a compound having a phosphorescence quantum yield of phosphorescence of less than 0.1 at room temperature (25 ° C.), more preferably a compound having a phosphorescence quantum yield of less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer.

Moreover, it is preferable that the excited state energy of a host compound is higher than the excited state energy of the light emission dopant contained in the same layer.
A host compound may be used independently or may be used in combination of multiple types. By using a plurality of types of host compounds, it is possible to adjust the movement of electric charges, and it is possible to increase the efficiency of the organic EL element.

There is no restriction | limiting in particular as a host compound used for a light emitting layer, The compound conventionally used with an organic EL element can be used. For example, it may be a low molecular compound, a high molecular compound having a repeating unit, or a compound having a reactive group such as a vinyl group or an epoxy group.

As a known host compound, while having a hole transport ability or an electron transport ability, it prevents the light emission from becoming longer wavelength, and further, from the viewpoint of stability against heat generation during driving of the organic EL element at a high temperature or during element driving, It is preferable to have a high glass transition temperature (Tg). As a host compound, it is preferable that Tg is 90 degreeC or more, More preferably, it is 120 degreeC or more.
Here, the glass transition point (Tg) is a value determined by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).

Specific examples of known host compounds used in organic EL devices include, but are not limited to, compounds described in the following documents.

JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445, 2002-343568, 2002-141173, 2002-352957, 2002-203683, 2002-363227, 2002-231453, 2003-3165, 2002-234888, 2003-27048, 2002-255934, 2002-260861, 2002-280183, 2002-299060, 2002 -302516, 2002-305083, 2002-305084, 2002-308837, US Patent Publication No. 20030175553, United States Patent Publication No. 20060280965, United States Patent Publication No. 20050112407, United States Patent Publication 20090017330, U.S. Patent Publication No. 20090030202, U.S. Patent Publication No. 20050238919, International Publication No. 20101039234, International Publication No. 200902126, International Publication No. No. 08056746, International Publication No. 2004093207, International Publication No. 2005089025, International Publication No. 20077063796, International Publication No. 2007063754, International Publication No. 2004078822, International Publication No. 2005030900, International Publication No. 20060146966, International Publication No. 2009086028. International Publication No. 2009003898, International Publication No. 20122023947, Japanese Unexamined Patent Application Publication No. 2008-074939, Japanese Unexamined Patent Application Publication No. 2007-254297, EP2034538, and the like.

[Electron transport layer]
The electron transport layer used for the organic EL element is made of a material having a function of transporting electrons, and has a function of transmitting electrons injected from the cathode to the light emitting layer.
The electron transport material may be used alone or in combination of two or more.
The total thickness of the electron transport layer is not particularly limited, but is usually in the range of 2 nm to 5 μm, more preferably 2 nm to 500 nm, and further preferably 5 nm to 200 nm.

Further, in the organic EL element, when the light generated in the light emitting layer is extracted from the electrode, the light extracted directly from the light emitting layer and the light extracted after being reflected by the electrode from which the light is extracted and the electrode located at the counter electrode are: It is known to cause interference. When light is reflected by the electrode, this interference effect can be efficiently utilized by appropriately adjusting the total film thickness of the electron transport layer between several nanometers and several micrometers.
On the other hand, since the voltage is likely to increase when the thickness of the electron transport layer is increased, the electron mobility of the electron transport layer is preferably 10 ⁻⁵ cm ² / Vs or more, particularly when the thickness is large. .

The material used for the electron transport layer (hereinafter referred to as an electron transport material) may have any of the electron injection property or the transport property or the hole barrier property. Any one can be selected and used.

Examples include nitrogen-containing aromatic heterocyclic derivatives, aromatic hydrocarbon ring derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, silole derivatives, and the like.

Examples of the nitrogen-containing aromatic heterocyclic derivatives include carbazole derivatives, azacarbazole derivatives (one or more carbon atoms constituting the carbazole ring are substituted with nitrogen atoms), pyridine derivatives, pyrimidine derivatives, pyrazine derivatives, pyridazine derivatives, triazine derivatives. Quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, azatriphenylene derivatives, oxazole derivatives, thiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, benzimidazole derivatives, benzoxazole derivatives, benzthiazole derivatives, and the like.
Examples of the aromatic hydrocarbon ring derivative include naphthalene derivatives, anthracene derivatives, triphenylene and the like.

Further, a metal complex having a quinolinol skeleton or a dibenzoquinolinol skeleton as a ligand, such as tris (8-quinolinol) aluminum (Alq3), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7- Dibromo-8-quinolinol) aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and metal complexes thereof A metal complex in which the central metal is replaced with In, Mg, Cu, Ca, Sn, Ga, or Pb can also be used as an electron transporting material.

In addition, metal-free or metal phthalocyanine, or those having the terminal substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. In addition, the distyrylpyrazine derivative exemplified as the material for the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material.
In addition, a polymer material in which these materials are introduced into a polymer chain, or a polymer material having these materials as a polymer main chain can also be used.

In an organic EL element, a doping material may be doped into the electron transport layer as a guest material to form an electron transport layer having a high n property (electron rich). Examples of the doping material include metal compounds such as metal complexes and metal halides, and other n-type dopants. Specific examples of the electron transport layer having such a structure include, for example, JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J. Appl. Phys., 95, 5773 (2004) and the like.

Specific examples of known preferable electron transport materials used in the organic EL device include, but are not limited to, compounds described in the following documents.
U.S. Pat.No. 6,528,187, U.S. Pat.No. 7,230,107, U.S. Patent Publication No. 20050025993, U.S. Pat. Publication No. 2004036077, U.S. Pat. Publication No. 200901115316, U.S. Pat. Publication No. 20090101870, U.S. Pat. 2003060956, WO200008132085, Appl. Phys. Lett. 75, 4 (1999), Appl. Phys. Lett. 79, 449 (2001), Appl. Phys. Lett. 81, 162 (2002), Appl. Phys. Lett. 81, 162 (2002), Appl. Phys. Lett. 79, 156 (2001), US Patent No. 7964293, US Patent Publication No. 2009030202, International Publication No. 20040980975, International Publication No. 2004063159, International Publication No. 20050885387, International Publication No. 20060606791, International Publication No. 2007086 No. 52, International Publication No. WO 200814690, International Publication No. 2009090442, International Publication No. 2009066779, International Publication No. 200905253, International Publication No. 20101086935, International Publication No. 2010150593, International Publication No. 20110047707, EP23111826, JP JP2010-251675A, JP2009-209133A, JP2009-124114A, JP2008-277810A, JP2006-156445A, JP2005-340122A, JP2003-340122A. No. 45662, No. 2003-31367, No. 2003-282270, International Publication No. 201212115034, etc.

More preferable electron transport materials include pyridine derivatives, pyrimidine derivatives, pyrazine derivatives, triazine derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, azacarbazole derivatives, and benzimidazole derivatives.

[Hole blocking layer]
The hole blocking layer is a layer having a function of an electron transport layer in a broad sense. Preferably, it is made of a material having a function of transporting electrons and a small ability to transport holes. By blocking holes while transporting electrons, the recombination probability of electrons and holes can be improved.
Moreover, the structure of the above-mentioned electron carrying layer can be used as a hole-blocking layer as needed.
The hole blocking layer provided in the organic EL element is preferably provided adjacent to the cathode side of the light emitting layer.

In the organic EL element, the thickness of the hole blocking layer is preferably in the range of 3 to 100 nm, more preferably in the range of 5 to 30 nm.
As the material used for the hole blocking layer, the material used for the above-described electron transport layer is preferably used, and the material used as the above-described host compound is also preferably used for the hole blocking layer.

[Electron injection layer]
The electron injection layer (also referred to as “cathode buffer layer”) is a layer provided between the cathode and the light emitting layer in order to lower the driving voltage and improve the light emission luminance. An example of an electron injection layer can be found in the second chapter, Chapter 2, “Electrode Materials” (pages 123-166) of “Organic EL devices and their industrialization front line (issued by NTT Corporation on November 30, 1998)”. Are listed.

In the organic EL element, the electron injection layer is provided as necessary, and is provided between the cathode and the light emitting layer or between the cathode and the electron transport layer as described above.
The electron injection layer is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 nm, depending on the material. Moreover, the nonuniform film | membrane in which a constituent material exists intermittently may be sufficient.

Details of the electron injection layer are also described in JP-A-6-325871, JP-A-9-17574, and JP-A-10-74586. Specific examples of materials preferably used for the electron injection layer include metals typified by strontium and aluminum, alkali metal compounds typified by lithium fluoride, sodium fluoride, and potassium fluoride, magnesium fluoride, and fluoride. Examples thereof include alkaline earth metal compounds typified by calcium, metal oxides typified by aluminum oxide, metal complexes typified by lithium 8-hydroxyquinolate (Liq), and the like. Moreover, it is also possible to use the above-mentioned electron transport material.
Moreover, the material used for said electron injection layer may be used independently, and may be used in combination of multiple types.

[Hole transport layer]
The hole transport layer is made of a material having a function of transporting holes. The hole transport layer is a layer having a function of transmitting holes injected from the anode to the light emitting layer.

In the organic EL device, the total thickness of the hole transport layer is not particularly limited, but is usually in the range of 5 nm to 5 μm, more preferably 2 nm to 500 nm, and further preferably 5 nm to 200 nm.

The material used for the hole transport layer (hereinafter referred to as a hole transport material) may have any of a hole injection property or a transport property and an electron barrier property. As the hole transport material, an arbitrary material can be selected and used from conventionally known compounds. The hole transport material may be used alone or in combination of two or more.

Hole transport materials include, for example, porphyrin derivatives, phthalocyanine derivatives, oxazole derivatives, oxadiazole derivatives, triazole derivatives, imidazole derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, hydrazone derivatives, stilbene derivatives, polyarylalkane derivatives, tria Reelamine derivatives, carbazole derivatives, indolocarbazole derivatives, isoindole derivatives, acene derivatives such as anthracene and naphthalene, fluorene derivatives, fluorenone derivatives, polyvinyl carbazole, polymer materials having aromatic amine introduced in the main chain or side chain, or Oligomer, polysilane, conductive polymer or oligomer (eg, PEDOT: PSS, aniline copolymer, polyaniline, polythiophene, etc.) And the like.

Examples of the triarylamine derivative include a benzidine type typified by α-NPD, a starburst type typified by MTDATA, and a compound having fluorene or anthracene in the triarylamine linking core part.

In addition, hexaazatriphenylene derivatives described in JP-T-2003-519432 and JP-A-2006-135145 can also be used as the hole transport material.
Furthermore, a hole transport layer having a high p property doped with impurities can also be used. For example, the configurations described in JP-A-4-297076, JP-A-2000-196140, 2001-102175, J. Appl. Phys., 95, 5773 (2004), etc. It can also be applied to the transport layer.
Also, so-called p-type hole transport materials and p-type materials as described in JP-A-11-251067 and J. Huang et.al. (Applied Physics Letters 80 (2002), p. 139). Inorganic compounds such as -Si and p-type -SiC can also be used. Further, ortho-metalated organometallic complexes having Ir or Pt as the central metal as typified by Ir (ppy) ₃ are also preferably used.

Although the above-mentioned materials can be used as the hole transport material, a triarylamine derivative, a carbazole derivative, an indolocarbazole derivative, an azatriphenylene derivative, an organometallic complex, or an aromatic amine is introduced into the main chain or side chain. The polymer materials or oligomers used are preferably used.

Specific examples of the hole transport material used for the organic EL element include, but are not limited to, the compounds described in the following documents in addition to the documents listed above.
Appl. Phys. Lett. 69, 2160 (1996), J. Lμmin. 72-74, 985 (1997), Appl. Phys. Lett. 78, 673 (2001), Appl. Phys. Lett. 90, 183503 (2007) ), Appl. Phys. Lett. 90, 183503 (2007), Appl. Phys. Lett. 51, 913 (1987), Synth. Met. 87, 171 (1997), Synth. Met. 91, 209 (1997), Synth. Met. 111,421 (2000), SID Symposiμm Digest, 37, 923 (2006), J. Mater. Chem. 3, 319 (1993), Adv. Mater. 6, 677 (1994), Chem. Mater. 15, 3148 (2003), US Patent Publication No. 20030162053, US Patent Publication No. 200201558242, US Patent Publication No. 20060240279, US Patent Publication No. 20080220265, US Patent No. 5061569, International Publication No. 2007002683, International Publication No. 2009018099. , EP650955, U.S. Patent Publication No. 20080124572, U.S. Pat. Publication No. 2007078938, U.S. Pat. No. 106,190, U.S. Patent Publication No. 20080018221, WO 2012115034, JP-T 2003-519432, JP 2006-135145, JP-U.S. Patent Application No. 13/585981

[Electron blocking layer]
The electron blocking layer is a layer having a function of a hole transport layer in a broad sense. Preferably, it is made of a material having a function of transporting holes and a small ability to transport electrons. The electron blocking layer can improve the probability of recombination of electrons and holes by blocking electrons while transporting holes.

Moreover, the structure of the above-described hole transport layer can be used as an electron blocking layer of an organic EL element as necessary. The electron blocking layer provided in the organic EL element is preferably provided adjacent to the anode side of the light emitting layer.

The thickness of the electron blocking layer is preferably in the range of 3 to 100 nm, and more preferably in the range of 5 to 30 nm.
As a material used for an electron blocking layer, the material used for the above-mentioned hole transport layer can be preferably used. Moreover, the material used as the above-mentioned host compound can also be preferably used as the electron blocking layer.

[Hole injection layer]
The hole injection layer (also referred to as “anode buffer layer”) is a layer provided between the anode and the light emitting layer in order to lower the driving voltage and improve the light emission luminance. An example of the hole injection layer is “Organic EL device and its industrialization front line (November 30, 1998, issued by NTT)”, Chapter 2, Chapter 2, “Electrode material” (pages 123-166). It is described in.
The hole injection layer is provided as necessary, and is provided between the anode and the light emitting layer or between the anode and the hole transport layer as described above.

Details of the hole injection layer are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like.
Examples of the material used for the hole injection layer include the materials used for the hole transport layer described above. Among them, phthalocyanine derivatives represented by copper phthalocyanine, hexaazatriphenylene derivatives as described in JP-T-2003-519432, JP-A-2006-135145, etc., metal oxides represented by vanadium oxide, amorphous Conductive polymers such as carbon, polyaniline (emeraldine) and polythiophene, orthometalated complexes represented by tris (2-phenylpyridine) iridium complex, and triarylamine derivatives are preferred.
The materials used for the hole injection layer described above may be used alone or in combination of two or more.

[Contains]
The light emitting functional layer constituting the organic EL element may further contain other inclusions.
Examples of the inclusion include halogen elements such as bromine, iodine, and chlorine, halogenated compounds, alkali metals such as Pd, Ca, and Na, alkaline earth metals, transition metal compounds, complexes, and salts.

The content of the inclusion can be arbitrarily determined, but is preferably 1000 ppm or less, more preferably 500 ppm or less, and even more preferably 50 ppm or less with respect to the total mass% of the contained layer. .
However, it is not within this range depending on the purpose of improving the transportability of electrons and holes or the purpose of favoring the exciton energy transfer.

[Method of forming light emitting functional layer]
A method for forming a light emitting functional layer (hole injection layer, hole transport layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) of the organic EL element will be described.
The method for forming the light emitting functional layer is not particularly limited, and can be formed by a conventionally known method such as a vacuum deposition method or a wet method (wet process).

Examples of the wet method include a spin coating method, a casting method, an ink jet method, a printing method, a die coating method, a blade coating method, a roll coating method, a spray coating method, a curtain coating method, and an LB method (Langmuir-Blodgett method). From the viewpoint of obtaining a homogeneous thin film easily and high productivity, a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, or a spray coating method is preferable.

Examples of the liquid medium for dissolving or dispersing the material of the light emitting functional layer in the wet method include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, and the like. Aromatic hydrocarbons such as mesitylene and cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, and organic solvents such as DMF and DMSO can be used.
Moreover, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

When a vapor deposition method is employed for forming each layer constituting the light emitting functional layer, the vapor deposition conditions vary depending on the type of compound used, etc., but generally the boat heating temperature is 50 ° C. to 450 ° C., and the degree of vacuum is 10 ⁻⁶ Pa to 10 ^−. It is desirable to appropriately select ² Pa, a deposition rate of 0.01 nm / second to 50 nm / second, a substrate temperature of −50 ° C. to 300 ° C., and a film thickness of 0.1 nm to 5 μm, preferably 5 nm to 200 nm.

For the formation of the organic EL element, it is preferable to consistently produce the light emitting functional layer to the cathode by a single evacuation, but it may be taken out halfway and subjected to different film forming methods. In that case, it is preferable to perform the work in a dry inert gas atmosphere.
Different formation methods may be applied for each layer.

[anode]
As an anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, and a mixture thereof having a high work function (4 eV or more, preferably 4.3 eV or more) is used. Specific examples of such an electrode substance include metals such as Au and Ag, alloys thereof, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used.

As the anode, a thin film is formed by depositing these electrode materials by a method such as vapor deposition or sputtering, and a pattern having a desired shape is formed by a photolithography method. Alternatively, when pattern accuracy is not so required (about 100 μm or more), the pattern may be formed through a mask having a desired shape when the electrode material is formed by vapor deposition or sputtering.
In the case of using a coatable material such as an organic conductive compound, a wet film forming method such as a printing method or a coating method can be used.

When the emitted light is extracted from the anode side, it is desirable that the transmittance be greater than 10%. The sheet resistance as the anode is several hundred Ω / sq. The following is preferred. Further, although the thickness of the anode depends on the material, it is usually selected in the range of 10 nm to 1 μm, preferably 10 nm to 200 nm.

[cathode]
As the cathode, an electrode substance made of a metal having a low work function (4 eV or less) (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, aluminum, rare earth metals and the like.

Among these, a mixture of an electron injecting metal and a second metal having a work function value larger and more stable than that of the electron injecting metal, for example, magnesium / Silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred.

The cathode can be produced by using the above electrode material by vapor deposition or sputtering. The sheet resistance of the cathode is several hundred Ω / sq. The following is preferred. The thickness of the cathode is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm.

In order to transmit the emitted light, if one of the electrodes of the organic EL element is transparent or translucent, the light emission luminance is improved and it is convenient.
A transparent or semi-transparent cathode can be produced by producing a conductive transparent material mentioned in the description of the anode on the cathode after producing the metal with a thickness of 1 nm to 20 nm. By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

[Support substrate]
The support substrate 20 (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL element is not particularly limited in the type of glass, plastic, etc., and even if it is transparent, it is opaque. It may be. When light is extracted from the support substrate 20 side, the support substrate 20 is preferably transparent. Examples of the transparent support substrate 20 preferably used include glass, quartz, and a transparent resin film. A particularly preferable support substrate 20 is a resin film capable of giving flexibility to the organic EL element.

Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate, cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfone , Polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylates, cyclone resins such as Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Etc.

On the surface of the resin film, a barrier film made of an inorganic film, an organic film, or a hybrid film of both may be formed. The barrier film had a water vapor transmission rate (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) of 0.01 g / (m ² · 24 h) measured by a method according to JIS K 7129-1992. The following barrier films are preferred. Furthermore, the oxygen permeability measured by a method according to JIS K 7126-1987 is 10 ⁻³ ml / (m ² · 24 h · atm) or less, and the water vapor permeability is 10 ⁻⁵ g / (m ² · 24h) The following high-barrier film is preferable.

The material for forming the barrier film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Furthermore, in order to improve the brittleness of the barrier film, it is more preferable to have a laminated structure of these inorganic layers and layers made of organic materials. Although there is no restriction | limiting in particular about the order of lamination | stacking of an inorganic layer and a light emitting functional layer, It is preferable to laminate | stack both alternately several times.

The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used. For example, an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is preferable.

Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, ceramic substrates, and the like.

[Sealing]
The organic EL element may include a sealing portion.
Although the organic EL emits light with a small amount of power, it is weak against moisture and a non-light emitting portion is formed by moisture absorption, so that it is preferably sealed with a sealing portion.

Examples of the sealing means used for sealing the organic EL element include a method of bonding a sealing member, an electrode, and a support substrate with an adhesive. As a sealing member, it should just be arrange | positioned so that the display area | region of an organic EL element may be covered, and it may be concave plate shape or flat plate shape. Moreover, transparency and electrical insulation are not particularly limited.

Specific examples include a glass plate, a polymer plate / film, and a metal plate / film.
Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz.
Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone.
Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.
For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

In order to reduce the thickness of the organic EL element, it is preferable to use a polymer film or a metal film. Further, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ ml / (m ² / 24h) or less, and was measured by a method according to JIS K 7129-1992. water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)%) is preferably at ^{^{1 × 10 -3 g / (m}} 2 / 24h) or less.

Examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

In addition, since an organic EL element may deteriorate by heat processing, what can be adhesively cured from room temperature to 80 ° C. or lower is preferable. Further, a desiccant may be dispersed in the adhesive. Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.

In addition, a sealing film is formed by forming an inorganic or organic layer on the electrode on the side facing the supporting substrate with the light emitting functional layer sandwiched between and covering the electrode and the light emitting functional layer. You can also In this case, the material for forming the sealing film may be any material having a function of suppressing entry of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used.

Furthermore, in order to improve the brittleness of the sealing film, it is preferable to have a laminated structure of an inorganic layer and a layer made of an organic material, like the above-described barrier film. The method for forming these films is not particularly limited. For example, vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

Injecting a gas phase with an inert gas such as nitrogen or argon or a liquid phase with an inert liquid such as fluorinated hydrocarbon or silicon oil into the gap between the sealing member and the display area of the organic EL element. Is preferred. Further, the gap between the sealing member and the display area of the organic EL element can be evacuated.

Furthermore, a hygroscopic compound can be enclosed in the gap between the sealing member and the display area of the organic EL element.
Examples of the hygroscopic compound include metal oxides such as sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, and aluminum oxide, sulfates such as sodium sulfate, calcium sulfate, magnesium sulfate, and cobalt sulfate, calcium chloride, Magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide and other metal halides, barium perchlorate, and perchloric acids such as magnesium perchlorate Can be mentioned. Anhydrous salts are preferably used as sulfates, metal halides and perchloric acids.

[Protective film, protective plate]
A protective film or a protective plate may be provided outside the sealing film or sealing film for sealing the organic EL element in order to increase the mechanical strength of the element. In particular, when the organic EL element is sealed with a sealing film, the mechanical strength is not necessarily high, and thus a protective film or a protective plate is preferably provided. Examples of the material that can be used as the protective film or the protective plate include a glass plate, a polymer plate / film, a metal plate / film, and the like, similar to the above-described sealing member. As the protective film or protective plate, it is preferable to use a polymer film that can be reduced in weight and thickness.

[Usage]
The organic EL element can be applied to electronic devices such as display devices, displays, and various light emission sources.
Examples of light-emitting light sources include lighting devices such as home lighting and interior lighting, backlights for clocks and liquid crystals, signboard advertisements, traffic lights, optical storage media and other light sources, light sources for electrophotographic copying machines, and light sources for optical communication processors. Examples include, but are not limited to, a light source of an optical sensor. In particular, it can be effectively used as a backlight of a liquid crystal display device and an illumination light source.

In the organic EL element, patterning may be performed by a metal mask, an inkjet printing method, or the like at the time of film formation as necessary. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire element layer may be patterned. In manufacturing the element, a conventionally known method can be used.

[Driving method]
In the organic EL element described above, in the first light emitting unit 18, the first light emitting functional layer 11 is sandwiched between the first electrode 14 and the second electrode 15. The second light emitting functional layer 12 is sandwiched between the second electrode 15 and the third electrode 16. In the second light emitting unit 19, the first light emitting functional layer 11 is sandwiched between the first electrode 14 and the second electrode 15. The third light emitting functional layer 13 is sandwiched between the second electrode 15 and the third electrode 16.

That is, in the first light emitting unit 18 and the second light emitting unit 19, the second electrode 15 is configured as a common electrode for the first light emitting functional layer 11 and the second light emitting functional layer 12 or the third light emitting functional layer 13. ing.
Therefore, for example, the second electrode 15 can function as a cathode common to the first light emitting functional layer 11, the second light emitting functional layer 12, and the third light emitting functional layer 13. The first electrode 14 and the third electrode 16 can function as the anode of the first light emitting functional layer 11 or the second light emitting functional layer 12 and the third light emitting functional layer 13.

FIG. 2 shows driving waveforms of the organic EL element having such a configuration.
As shown in FIG. 2, in the first light emitting unit 18, the first light emitting functional layer 11 and the second light emitting functional layer 12 can emit light simultaneously. Moreover, in the 2nd light emission unit 19, the 1st light emission functional layer 11 and the 3rd light emission functional layer 13 can be light-emitted simultaneously.
For this reason, the luminous efficiency of an organic EL element can be improved.

Furthermore, the first light emitting unit 18 and the second light emitting unit 19 can also be duty driven. For this reason, the 2nd light emission functional layer 12 and the 3rd light emission functional layer 13 can control light emission separately. Accordingly, any color adjustment of the organic EL element is possible.

In the organic EL element having the above-described configuration, the first light emitting functional layer 11 common to the first light emitting unit 18 and the second light emitting unit 19 is formed of a light emitting layer having inferior light emission efficiency, and the second light emitting functional layer 12 and the third light emitting functional layer 12 are provided. The light emitting functional layer 13 is preferably composed of a light emitting layer having a light emitting efficiency higher than that of the first light emitting functional layer 11.

When the first light emitting unit 18 and the second light emitting unit 19 are driven, the first light emitting functional layer 11 common to the first light emitting unit 18 and the second light emitting unit 19 can emit light. For this reason, two or more light emitting functional layers can emit light simultaneously, and the light emission efficiency of the organic EL element is improved.

Further, the second light emitting functional layer 12 and the third light emitting functional layer 13 can also drive the first light emitting unit 18 and the second light emitting unit 19 in accordance with the respective light emission efficiencies.
For this reason, arbitrary toning becomes possible in an organic EL element.

Further, the organic EL element having the above-described configuration can also emit the first light emitting unit 18 and the second light emitting unit 19 simultaneously. That is, the two first light emitting functional layers 11, the second light emitting functional layer 12, and the third light emitting functional layer 13 can emit light simultaneously. In this case, the light emission efficiency is improved as compared with the case where the light emitting layers of the respective colors of the organic EL element are driven by duty.

Further, in the organic EL element having the above configuration, even if the second electrode 15 is common, the first light emitting functional layer 11, the second light emitting functional layer 12, or the third light emitting functional layer 13 can be driven independently. Is possible. For this reason, more precise color matching can be achieved by arbitrarily driving each light emitting functional layer.

In the organic EL element having the above-described configuration, the above-described first light-emitting unit 18 and second light-emitting unit 19 are duty-driven, the first light-emitting unit 18 and the second light-emitting unit 19 are simultaneously emitted, and By combining arbitrary driving methods such as a method of driving each light emitting functional layer, it is possible to configure an organic EL element capable of achieving both precise color matching and improvement in light emission efficiency.

[effect]
In the organic EL element having the above-described configuration, the area of the light emitting layer with low light emission efficiency can be increased by using the light emitting layer with low light emission efficiency for the first light emitting functional layer 11. Therefore, the area of the light emitting layer with low light emission efficiency can be increased without reducing the aperture ratio of the light emitting layer with high light emission efficiency. As a result, the light emission efficiency and brightness of the organic EL element can be improved.
Further, by arbitrarily selecting a combination of emission colors of the first light emitting functional layer 11 and the second light emitting functional layer 12 or the third light emitting functional layer 13, an increase in the area of the light emitting layer having a lower light emitting efficiency or an opening The rate can be improved.

Therefore, for example, red light emission and green light emission use a phosphorescent material in order to obtain high light emission efficiency, and blue emits blue light in the first light emitting functional layer 11 even when a fluorescent material is used in order to obtain color purity. By providing the light emitting layer and providing the second light emitting functional layer 12 or the third light emitting functional layer 13 with the red or green light emitting layer, the area ratio of the blue light emitting layer is made larger than that of the red or green light emitting layer. be able to.
Since the life can be extended by greatly increasing the area of the blue light emitting layer, the life balance of each light emitting layer can be adjusted. Furthermore, even if the area of the blue light-emitting layer is greatly increased, it is not necessary to reduce the area of the green or red light-emitting layer, so that the aperture ratio can be reduced and the luminance gradient during color emission can be suppressed. .

Further, by adjusting the areas of the first light emitting unit 18 and the second light emitting unit 19, the luminance of the second light emitting functional layer 12 and the third light emitting functional layer 13 can be adjusted.
Also in this case, since the total area of the first light emitting unit 18 and the second light emitting unit 19 is the total area of the first light emitting functional layer 11, the luminance of the first light emitting functional layer 11 is improved. Moreover, the lifetime of the 1st light emission functional layer 11, the 2nd light emission functional layer 12, and the 3rd light emission functional layer 13 can be adjusted by changing an area according to light emission efficiency.

According to the configuration of the organic EL element described above, the aperture ratio of an arbitrary light emitting layer can be improved without narrowing the light emitting region of another light emitting layer, so that the luminous efficiency can be improved without impairing the visibility. Become. Therefore, the display quality of the organic EL element can be improved.

In addition, in the organic EL element, the stacking order of the light emitting functional layers of each color, the polarity of the electrodes, and the like are not limited to the above-described embodiments, and other configurations may be employed. It is only necessary that the light emitting functional layer is laminated via the common electrode. The common electrode may function as a cathode or an anode for the stacked light emitting functional layers, and the electrodes other than the common electrode may function as electrodes having a polarity opposite to the common electrode for the stacked light emitting functional layers. There are no particular limitations on the number of stacked light emitting functional layers, the area of the light emitting functional layers, the number of light emitting units, and the like.

In the above-described embodiment, the first to third light emitting functional layers are configured to include the light emitting layers having different light emission colors. However, the present invention is not limited to this, and the first to third light emitting functional layers have the same structure. A light emitting functional layer having the same light emitting color may be stacked, or a light emitting functional layer other than the first to third light emitting functional layers may be included in the light emitting unit. The configuration of the light emitting layer applied to the light emitting functional layer and the combination of the color tone are not particularly limited, and any configuration can be adopted.

Furthermore, in the above-described embodiment, in FIG. 1, the layers from the first electrode to the third electrode are separated by the first light emitting unit and the second light emitting unit. As long as it functions as an organic EL element, the first light emitting unit and the second light emitting unit may have a common configuration. For example, the first electrode may have a common configuration for the first light emitting unit and the second light emitting unit. Further, for example, each layer constituting the first light emitting functional layer, in particular, the electron transport layer, the hole transport layer, and the like may be configured in common between the first light emitting unit and the second light emitting unit.

<2. Organic Electroluminescence Element (Second Embodiment and Modification)>
Next, a second embodiment of the organic electroluminescence element (organic EL element) will be described. In addition, the organic EL element of 2nd Embodiment is the structure similar to the above-mentioned 1st Embodiment except that the laminated structure of each light emitting functional layer and an electrode differs. For this reason, description is abbreviate | omitted about the structure similar to the above-mentioned 1st Embodiment.

[Configuration of organic electroluminescence element]
In FIG. 3, the schematic block diagram (sectional drawing) of the organic EL element of 2nd Embodiment is shown.
The organic EL element shown in FIG. 3 includes a first electrode 34, a first light emitting functional layer 31, a second electrode 35, a second light emitting functional layer 32, a third light emitting functional layer 33, and a third electrode 36. 39. In addition, the light emitting unit 39 having these configurations is mounted on the support substrate 20. Furthermore, an insulating layer 37 surrounding the light emitting region of the light emitting unit 39 is provided.

In the light emitting unit 39, the first electrode 34 is provided on the support substrate 20. Further, in the light emitting unit 39, the first electrode 34 is continuously provided over the entire area in a predetermined region of the light emitting region of the light emitting unit 39. The 1st electrode 34 is connected to the power circuit of the drive part of the organic EL element which is not illustrated.

The first light emitting functional layer 31 is provided on the first electrode 34. Similar to the first electrode 34, the first light emitting functional layer 31 is continuously provided over the entire area within a predetermined region of the light emitting region of the light emitting unit 39.

The second electrode 35 is provided on the first light emitting functional layer 31. Similar to the first electrode 34, the second electrode 35 is provided continuously over the entire region within a predetermined region of the light emitting region of the organic EL element. Similar to the first electrode 34 described above, the second electrode 35 is connected to a power supply circuit of an organic EL element driving unit (not shown).

The second light emitting functional layer 32 and the third light emitting functional layer 33 are provided on the second electrode 35. The second light emitting functional layer 32 and the third light emitting functional layer 33 are provided independently at predetermined intervals. The second light emitting functional layers 32 and the third light emitting functional layers 33 are alternately arranged.

The third electrode 36 is provided on the second light emitting functional layer 32 and the third light emitting functional layer 33. The third electrode 36 is provided independently on the second light emitting functional layer 32 and the third light emitting functional layer 33 that are provided separately from each other, and is independent of the second light emitting functional layer 32 or the third light emitting functional layer 33. Thus, a potential can be supplied. The third electrode 36 is connected to a power supply circuit of a driving unit (not shown) of the organic EL element, similarly to the first electrode 34 described above.

The first light-emitting functional layer 31, the second light-emitting functional layer 32, and the third light-emitting functional layer 33 can have the same configuration as the light-emitting functional layer described in the first embodiment, and include at least one layer. The organic light emitting layer is provided.

In addition, the 2nd light emission functional layer 32 and the 3rd light emission functional layer 33 may each be comprised with the same area, and may be comprised with a different area. Further, in the organic EL element of this example, a configuration in which a plurality of second light emitting functional layers 32 and third light emitting functional layers 33 are provided in one light emitting unit 39 is shown. In addition, at least one third light emitting functional layer 33 may be provided. Further, the organic EL element may be configured to include a plurality of light emitting units 39, or may be configured to include a plurality of second light emitting functional layers 32 and a third light emitting functional layer 33 in a single light emitting unit 39. . In the case where a plurality of light emitting units 39 are provided in the organic EL element, an insulating layer 37 is disposed between the light emitting units 39.

[Driving method]
The organic EL element described above has a configuration in which the second light emitting functional layer 32 or the third light emitting functional layer 33 is laminated on the first light emitting functional layer 31 via the second electrode 35 in the light emitting unit 39. The first light emitting functional layer 31 is sandwiched between the first electrode 34 and the second electrode 35. The second light emitting functional layer 32 and the third light emitting functional layer 33 are shared by the first light emitting functional layer 31, the second light emitting functional layer 32, and the third light emitting functional layer 33, respectively. It is sandwiched between independent third electrodes 36.

In the organic EL element, the first electrode 34 and the third electrode 36 have the same polarity, and the second electrode 35 has the opposite polarity to the first electrode 34 and the third electrode 36.
For example, in the present example, the first electrode 34 described above functions as a cathode with respect to the first light emitting functional layer 31. Similarly, the third electrode 36 functions as a cathode with respect to the second light emitting functional layer 32 and the third light emitting functional layer 33 in this example.
In addition, the second electrode 35 functions as an anode with respect to the first light emitting functional layer 31 in this example. Further, the second electrode 35 also functions as an anode for the second light emitting functional layer 32 and the third light emitting functional layer 33 provided on the second electrode 35.

That is, the second electrode 35 is configured as a common electrode for the first light emitting functional layer 31 and the second light emitting functional layer 32 and the third light emitting functional layer 33 formed on the second electrode 35. Since the third electrode 36 is formed independently, the second light emitting functional layer 32 and the third light emitting functional layer 33 can be driven independently.

FIG. 4 shows driving waveforms of the organic EL element having such a configuration.
As shown in FIG. 4, when the first electrode 34 and the second electrode 35 are driven, the first light emitting functional layer 31 provided in the entire light emitting region can emit light. The third electrode 36 provided on the second light emitting functional layer 32 and the third electrode 36 provided on the third light emitting functional layer 33 in accordance with the driving of the first electrode 34 and the second electrode 35. Are independently driven, the second light emitting functional layer 32 and the third light emitting functional layer 33 can arbitrarily emit light.

Thus, the 1st light emission functional layer 31 and the 2nd light emission functional layer 32 can be light-emitted simultaneously. Moreover, the 1st light emission functional layer 31 and the 3rd light emission functional layer 33 can be light-emitted simultaneously. Further, the first light emitting functional layer 31, the second light emitting functional layer 32, and the third light emitting functional layer 33 can emit light simultaneously.
For this reason, the luminous efficiency of an organic EL element can be improved.

Further, by driving the second electrode 35 and the third electrode 36 without driving the first electrode 34, the second light emitting functional layer 32 and the third light emitting function are not emitted without causing the first light emitting functional layer 31 to emit light. The layer 33 can also emit light simultaneously or independently. Further, by driving only the first electrode 34 and the second electrode 35, it is possible to cause only the first light emitting functional layer 31 to emit light.

Thus, even if the second electrode 35 is common, the first light emitting functional layer 31, the second light emitting functional layer 32, or the third light emitting functional layer 33 can be independently driven. . For this reason, for example, duty driving can be performed according to the light emission efficiency of each light emitting layer. In other words, precise color matching is possible by setting each light emitting functional layer to an arbitrary duty drive.

Therefore, in the configuration of the organic EL element of this example, the first light emitting functional layer 31, the second light emitting functional layer 32, and the third light emitting functional layer 33 are driven by duty, simultaneously emitted, and the first light emitting function. By arbitrarily combining driving methods such as the method of causing the layer 31 and the second light emitting functional layer 32 or the third light emitting functional layer 33 to emit light at the same time, it is possible to achieve both precise color matching and improvement in light emission efficiency. .

[effect]
In the organic EL element having the above configuration, for example, the area can be increased by using a light emitting layer having low light emission efficiency for the first light emitting functional layer 31. Therefore, the area of the light emitting layer with low light emission efficiency can be increased without reducing the aperture ratio of the light emitting layer with high light emission efficiency. As a result, the light emission efficiency and brightness of the organic EL element can be improved.

For this reason, for example, red light emission and green light emission use a phosphorescent material in order to obtain high light emission efficiency, and blue emits blue light in the first light emitting functional layer 31 even when a fluorescent material is used in order to obtain color purity. By providing the light emitting layer and providing the second light emitting functional layer 32 or the third light emitting functional layer 33 with the red or green light emitting layer, the area ratio of the blue light emitting layer is formed larger than that of the red or green light emitting layer. be able to.
For this reason, since the area of a blue light emitting layer can be increased significantly and the life difference with another light emitting layer can be offset, the life balance of each light emitting layer can be adjusted. Further, since it is not necessary to reduce the area of the green or red light emitting layer, it is possible to reduce the aperture ratio and suppress the luminance gradient during color emission.

Further, by adjusting the areas of the second light emitting functional layer 32 and the third light emitting functional layer 33, the luminance of the second light emitting functional layer 32 and the third light emitting functional layer 33 can be adjusted.
Also in this case, the total area of the first light emitting functional layer 31 is equal to or greater than the total area of the second light emitting functional layer 32 and the third light emitting functional layer 33, and the first light emitting functional layer 31 and the second light emitting functional layer. 32 and the lifetime of the third light emitting functional layer 13 can be adjusted.

As described above, in the organic EL element of the second embodiment, the area ratio of the first light emitting functional layer, the second light emitting functional layer, and the third light emitting functional layer can be arbitrarily adjusted. For this reason, even when the light emission efficiency of the first light emission functional layer, the second light emission functional layer, and the third light emission functional layer is different, the difference in light emission efficiency can be corrected by the area ratio. Therefore, the emission color of the organic EL element can be arbitrarily adjusted by adjusting the area ratio of the first light emitting functional layer, the second light emitting functional layer, and the third light emitting functional layer.

Furthermore, by arbitrarily selecting a combination of emission colors of the first light emitting functional layer 31 and the second light emitting functional layer 32 or the third light emitting functional layer 33, an increase in the area of the light emitting layer with low light emission efficiency, or an opening The rate can be improved.

[Modified example of organic electroluminescence element]
Next, a modified example of the organic electroluminescence element (organic EL element) of the second embodiment will be described. In addition, in the organic EL element of the modification of 2nd Embodiment, description is abbreviate | omitted about the structure similar to the above-mentioned 2nd Embodiment.

The structure of the organic EL element of the modification of 2nd Embodiment is shown in FIG.
The organic EL element shown in FIG. 5 differs from the second embodiment described above only in the polarities of the first electrode 34, the second electrode 35, and the third electrode 36. That is, in the organic EL element of the second embodiment described above, the first electrode 34 becomes the anode of the first light emitting functional layer 31. The second electrode 35 serves as the cathode of the first light emitting functional layer 31 and the anode of the second light emitting functional layer 32 and the third light emitting functional layer 33. Further, the third electrode 36 serves as a cathode of the second light emitting functional layer 32 and the third light emitting functional layer 33.

In the first light emitting functional layer 31, the arrangement of the cathode and the anode is opposite to that in the second embodiment. For this reason, when the 1st light emission functional layer 31 is provided with an electron carrying layer, a hole transport layer, etc. other than a light emitting layer, the lamination | stacking order of the 1st light emission functional layer 31 becomes reverse to the above-mentioned 2nd Embodiment. .

Further, in the organic EL element shown in FIG. 5, a switch 38 for switching driving of the first electrode 34, the second electrode 35, and the third electrode 36 is provided in the circuit of the driving unit. In the organic EL element shown in FIG. 5, a switch 38 having one circuit and two contacts is illustrated as a switch for switching in the circuit of the driving unit.

In the organic EL element having the above-described configuration, the driving of the first electrode 34 and the second electrode 35 or the driving of the second electrode 35 and the third electrode 36 can be arbitrarily controlled by switching the switch 38. For this reason, by driving the first electrode 34 and the second electrode 35, the first electrode 34 becomes an anode and the second electrode 35 becomes a cathode, and the first light emitting functional layer 31 emits light. Further, by driving the second electrode 35 and the third electrode 36, the second electrode 35 becomes an anode and the third electrode 36 becomes a cathode, and the second light emitting functional layer 32 and the third light emitting functional layer 33 emit light. .

As described above, in the organic EL element, the second electrode 35 is shared by the first light emitting functional layer 31, the second light emitting functional layer 32, or the third light emitting functional layer 33. Then, the first light emitting functional layer 31, the second light emitting functional layer 32, or the third light emitting functional layer 33 is arbitrarily selected by switching the polarity of the second electrode 35 between the cathode and the anode according to the driving timing. Can be emitted.

In this configuration, the first light emitting functional layer 31 and the second light emitting functional layer 32 or the third light emitting functional layer 33 cannot emit light simultaneously, but the second light emitting functional layer 32 and the third light emitting functional layer 33 are It is possible to emit light simultaneously. In addition, since the formation area of the first light emitting functional layer 31, the second light emitting functional layer 32, and the third light emitting functional layer 33 is the same as that of the second embodiment, the area of the light emitting layer is increased and the aperture ratio is improved. Can be made.
Furthermore, since the first light emitting functional layer 31, the second light emitting functional layer 32, or the third light emitting functional layer 33 can be driven independently, each layer can be arbitrarily driven to perform more precise color matching. Is possible.
Therefore, it is possible to configure an organic EL element capable of achieving both improvement in luminous efficiency and arbitrary color matching.

<3. Organic Electroluminescence Element (Third Embodiment)>
Next, a third embodiment of the organic electroluminescence element (organic EL element) will be described. In addition, the organic EL element of 3rd Embodiment is the structure similar to the above-mentioned 1st Embodiment except the laminated structure of each light emitting functional layer and an electrode. For this reason, description is abbreviate | omitted about the structure similar to the above-mentioned 1st Embodiment.

[Configuration of organic electroluminescence element]
In FIG. 6, the schematic block diagram (sectional drawing) of the organic EL element of 3rd Embodiment is shown.
The organic EL element shown in FIG. 6 includes a first electrode 44, a first light emitting functional layer 41, a second electrode 45, a second light emitting functional layer 42, a third electrode 46, a third light emitting functional layer 43, and a fourth electrode. 47 is provided. Further, the light emitting unit 49 having these configurations is mounted on the support substrate 20. Further, an insulating layer 48 serving as a partition wall is provided between the light emitting units 49.

The first electrode 44 is provided independently for each light emitting unit 49 on the support substrate 20. The first electrodes 44 are insulated from each other by an insulating layer 48. Further, the first electrode 44 is connected to a power supply circuit of an organic EL element driving unit (not shown).
A first light emitting functional layer 41 is provided on the first electrode 44.

A second electrode 45 is provided on the first light emitting functional layer 41. Similar to the first electrode 44 described above, the second electrode 45 is connected to a power supply circuit of an organic EL element driving unit (not shown).
A second light emitting functional layer 42 is provided on the second electrode 45.

A third electrode 46 is provided on the second light emitting functional layer 42. Similar to the first electrode 44 described above, the third electrode 46 is connected to a power supply circuit of a driving unit (not shown) of the organic EL element.
A third light emitting functional layer 43 is provided on the third electrode 46.

The fourth electrode 47 is provided on the third light emitting functional layer 43. The fourth electrode 47 is connected to a power supply circuit of a driving unit (not shown) of the organic EL element, similar to the first electrode 44 described above.

The first light-emitting functional layer 41, the second light-emitting functional layer 42, and the third light-emitting functional layer 43 can have the same configuration as the light-emitting functional layer described in the first embodiment, and include at least one layer. The organic light emitting layer is provided. In the organic EL element, the first light emitting functional layer 41, the second light emitting functional layer 42, and the third light emitting functional layer 43 have different light emitting layers.

The light emitting unit 49 includes three light emitting functional layers, a first light emitting functional layer 41, a second light emitting functional layer 42, and a third light emitting functional layer 43. Therefore, for example, the first light emitting functional layer 41 is configured to have a green (G) light emitting layer, the second light emitting functional layer 42 is configured to have a blue (B) light emitting layer, and the third light emitting functional layer 43 is formed. A structure having a red (R) light emitting layer is adopted.
As described above, in the organic EL element, the light emitting unit 49 includes the three light emitting functional layers, so that it is possible to obtain three colors of emitted light of RGB.

Further, the first light emitting functional layer 41 is sandwiched between the first electrode 44 and the second electrode 45. The second light emitting functional layer 42 is sandwiched between the second electrode 45 and the third electrode 46. Further, the third light emitting functional layer 43 is sandwiched between the third electrode 46 and the fourth electrode 47.
That is, the second electrode 45 is configured as a common electrode for the first light emitting functional layer 41 and the second light emitting functional layer 42 formed on the second electrode 45. Further, the third electrode 46 is configured as a common electrode for the second light emitting functional layer 42 and the third light emitting functional layer 43 formed on the third electrode 46.

The first electrode 44 and the third electrode 46 are electrodes having the same polarity, and the second electrode 45 and the fourth electrode 47 are electrodes having opposite polarities to the first electrode 44 and the third electrode 46. For example, in the present example, the first electrode 44 described above functions as a cathode with respect to the first light emitting functional layer 41. The second electrode 45 functions as an anode with respect to the first light emitting functional layer 41 and the second light emitting functional layer 42. The third electrode 46 functions as a cathode with respect to the second light emitting functional layer 42 and the third light emitting functional layer 43. The fourth electrode 47 functions as an anode with respect to the third light emitting functional layer 43.

[Driving method]
FIG. 7 shows drive waveforms in the organic EL element described above.
In the light emitting unit 49 of the organic EL element, the first electrode 44 and the third electrode 46 have the same polarity, and the second electrode 45 and the fourth electrode 47 are connected to the first electrode 44 and the light emitting functional layer. It functions as a polarity opposite to that of the third electrode 46. Therefore, as shown in FIG. 7, the first electrode 44, the second electrode 45 and the third electrode 46 serving as the shared electrode, and the fourth electrode 47 can be driven simultaneously. As a result, the first light emitting functional layer 41, the second light emitting functional layer 42, and the third light emitting functional layer 43 can emit light simultaneously.
For this reason, the luminous efficiency of an organic EL element can be improved.

Further, as shown in FIG. 7, the first light emitting functional layer 41 and the second light emitting functional layer 42 are caused to emit light simultaneously by simultaneously driving the first electrode 44, the second electrode 45, and the third electrode 46. Can do. Furthermore, as shown in FIG. 7, the second light emitting functional layer 42 and the third light emitting functional layer 43 are caused to emit light simultaneously by driving the second electrode 45, the third electrode 46, and the fourth electrode 47 simultaneously. Can do.

That is, in the light emitting unit 49, any one of the first light emitting functional layer 41 and the second light emitting functional layer 42 or the second light emitting functional layer 42 and the third light emitting functional layer 43 can be arbitrarily selected to emit light. it can. This can be selected by switching the electrode to be driven between the first electrode 44 and the fourth electrode 47.

At this time, the second light emitting functional layer 42 emits light during both the period during which the first light emitting functional layer 41 emits light and the period during which the third light emitting functional layer 43 emits light. Therefore, the second light emitting functional layer 42 has a longer light emission period than the first light emitting functional layer 41 and the third light emitting functional layer 43, and can increase the lighting rate. Therefore, for example, even when the second light emitting functional layer 42 is formed of a light emitting layer having inferior light emission efficiency, it is not necessary to increase the area for improving the luminance.

Further, the first light emitting functional layer 41 and the third light emitting functional layer 43 can be duty-driven according to the respective light emission efficiencies. For this reason, arbitrary toning becomes possible in an organic EL element.

As described above, according to the present embodiment, two or more light emitting functional layers can be caused to emit light simultaneously in the organic EL element. Furthermore, an organic EL element capable of arbitrary toning by duty driving can be configured. Therefore, it is possible to configure an organic EL element capable of achieving both improvement in luminous efficiency and arbitrary color matching.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[Production of Organic EL Element of Sample 101]
A sample 101 of the organic EL element having the configuration shown in FIG. 3 was prepared as follows.

(Support substrate)
First, a transparent substrate having an outer size of 90 mm × 90 mm was prepared as a support substrate for forming an organic EL element. The transparent substrate was then subjected to acetone ultrasonic cleaning, semi-clean ultrasonic cleaning, and ozone cleaning to clean the surface of the substrate.

(First electrode)
Next, the 1st electrode used as the anode of an organic EL element was formed on the wash | cleaned board | substrate. As a 1st electrode, 300 nm of ITO layers were formed using sputtering method. The first electrode is approximately 5 Ω / sq. It formed so that it might become a sheet resistance value of a grade.

DC magnetron sputtering was used for sputtering. The substrate was placed under a vacuum level of 90 ° C. and a vacuum level of 1 × 10 ⁻⁴ (Pa), oxygen 2% mixed argon gas was introduced at 0.5 Pa, and 500 W DC was applied to the ITO. An ITO layer was formed on the substrate by adding to the target. The ITO layer used in this example is approximately 5 Ω / sq. It was designed to have a sheet resistance value of about.

Next, the ITO layer was patterned in the shape of an electrode so that the light emitting portion was 80 mm × 80 mm. For patterning, a resist is spin-coated on a substrate by 1 μm, pre-baked at 80 ° C. for 5 minutes, exposed by an exposure machine, developed by immersing in NaOH for 3 minutes, rinsed with pure water, spin-dried and post-baked Was carried out at 100 ° C. for 40 minutes.

Etching of the ITO layer uses 15% aqueous ferric chloride solution, rinses with pure water after etching, soaks in NaOH for 3 minutes to strip the resist, strips the resist, similarly rinses with pure water, spin-dry By applying, it was etched into a desired shape.

(Insulating layer)
Next, an insulating layer made of polyimide was formed in order to prevent an electrical short in the vicinity of the ITO pattern edge serving as the anode.
First, the substrate on which the ITO patterning was completed was again subjected to acetone ultrasonic cleaning, semi-clean ultrasonic cleaning, spin drying, and ozone cleaning. Thereafter, polyimide was spin-coated to a thickness of 1 μm. Then, prebaking was performed at 85 ° C. for 3 minutes, and after exposure with an exposure machine, development was performed by immersing in 3% TMAH for 5 minutes. After development, pure water rinsing was performed, and post-baking was performed at 100 ° C. for 80 minutes after spin drying.

(First light emitting functional layer)
Next, a first light emitting functional layer emitting blue light was formed on the first electrode by vacuum deposition.
First, UV cleaning was performed for 5 minutes to activate the surface state of the first electrode, and then the substrate was placed in a vacuum deposition apparatus and evacuated to a vacuum degree of 1 × 10 ⁻⁵ (Pa).

After the evacuation was completed, each layer constituting the first light emitting functional layer was formed by vapor deposition as needed.
First, 30 nm of MoO ₃ was deposited as a hole injection layer and 50 nm of α-NPD was deposited as a hole transport layer on the first electrode.
Next, as a light emitting layer, a light emitting dopant having a blue light emitting color and a light emitting host material were deposited by evaporation so as to have a concentration of 3 to 5% of the light emitting dopant.
Next, 30 nm of Alq3 was formed as an electron transport layer, and 1 nm of LiF was formed as an electron injection layer.

(Second electrode)
Next, a second electrode serving as a cathode was formed on the first light emitting functional layer.
The second electrode was formed by depositing 15 nm of Al by EB vapor deposition so as to cover the first light emitting functional layer. The second electrode was taken out on one side of the substrate.

(Second light emitting functional layer, third light emitting functional layer)
Next, a second light emitting functional layer emitting green light and a third light emitting functional layer emitting red light were formed on the second electrode. The second light-emitting functional layer and the third light-emitting functional layer were each formed in a strip shape on the second electrode by being separately applied using a vapor deposition mask.
The second light emitting functional layer was formed so that the light emitting area line was 1 mm × 70 mm. The third light emitting functional layer was formed so that the light emitting area line was 2.3 mm × 70 mm. The space between the second light emitting functional layer and the third light emitting functional layer was formed to be 60 μm.
The alignment of the vapor deposition mask was corrected with a CCD camera having an accuracy of ± 5 μm, and a vapor deposition apparatus was used so that the desired position was obtained.
The second light emitting functional layer and the third light emitting functional layer were formed simultaneously as a common layer except for the light emitting layer and the third electrode.

First, as an electron injection layer for injecting electrons from Al of the second electrode, 1 nm of LiF was formed as a common layer of the second light emitting functional layer and the third light emitting functional layer. Next, similarly for the electron transport layer, Alq3 of 30 nm was formed as a common layer of the second light emitting functional layer and the third light emitting functional layer.

Next, only the light-emitting layer of the second light-emitting functional layer that emits green light is used to form a light-emitting dopant and a light-emitting host material at a concentration of 3% using a vapor deposition mask that opens the light-emitting region of the second light-emitting functional layer. Thus, 30 nm was formed by vapor deposition.

Next, only the light-emitting layer of the third light-emitting functional layer that emits red light is used to form a light-emitting dopant and a light-emitting host material with a light-emitting dopant of 0.5% using an evaporation mask having an opening in the light-emitting region of the third light-emitting functional layer. In order to obtain a concentration, 30 nm was deposited.

Next, using a vapor deposition mask capable of simultaneously forming the light emitting region of the second light emitting functional layer and the light emitting region of the third light emitting functional layer, the common holes of the second light emitting functional layer and the third light emitting functional layer are used. As a transport layer, α-NPD was formed to a thickness of 30 nm. Next, similarly, the hole injection layer was formed with 30 nm of MoO ₃ as a common layer of the second light emitting functional layer and the third light emitting functional layer.

(Third electrode)
Next, a third electrode serving as an anode was formed on the second light emitting functional layer and the third light emitting functional layer. As the third electrode, an Al layer having a thickness of 150 nm was formed by EB vapor deposition. For forming the third electrode, an opening capable of simultaneously forming the light emitting regions of the second light emitting functional layer and the third light emitting functional layer, and an opening of the lead routing portion to the end of the substrate for electrical connection of the third electrode A vapor deposition mask having the following was used.

(Sealing)
In order to seal the light emitting unit formed by the above steps, a sealing portion was formed. In this example, sealing was performed using a sealing substrate subjected to counterboring.
Specifically, engraving a 0.7mm counterbore into a glass can (t = 1.1mm) with an external size of 85mm x 85mm so as to leave leads on four sides, and attaching a hygroscopic agent to the same part, Was applied to adsorb.

In addition, a UV curable epoxy adhesive resin was applied as an adhesive to a region where the counterbore digging was not formed in a portion where the sealing substrate and the element substrate were in contact with each other, and was pressed against the element substrate.
Furthermore, in order to cure the adhesive, UV irradiation is performed from the sealing substrate side so that the integrated illuminance becomes 10 J with metal halide, and further, the adhesive is cured by thermal curing at 80 ° C. for about 1 hour to cure the adhesive. The curing of the agent was promoted, and the sealing substrate and the transparent substrate as the element substrate were bonded.

(Organic EL device)
Through the above steps, a sample 101 of the organic EL element was produced.
In the sample 101 described above, the first light-emitting functional layer is formed in a normal lamination in which a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer are stacked in this order on the first electrode. did. Further, the second light emitting functional layer and the third light emitting functional layer were formed by reverse lamination in which an electron injection layer, an electron transport layer, a light emitting layer, a hole transport layer, and a hole injection layer were stacked in this order on the second electrode. .
That is, in the sample 101, the first light emitting functional layer was formed by normal lamination, and the second light emitting functional layer and the third light emitting functional layer were formed by reverse lamination.

In the sample 101, the light emitting layers of the second light emitting functional layer and the third light emitting functional layer, and the third electrode were formed by patterning using an evaporation mask. For this reason, in consideration of vapor deposition blur due to wraparound from the vapor deposition mask, a large space area of the light emitting layer between the second light emitting functional layer and the third light emitting functional layer is formed in order to suppress short circuit and mixed color light emission due to vapor deposition blur.
The organic EL element of Sample 101 thus manufactured had an aperture ratio of 95% for the blue light emitting region, 28% for the green light emitting region, and 64% for the red light emitting region.

[Production of organic EL element of sample 102]
A sample 102 of the organic EL element having the configuration shown in FIG. 1 was prepared as follows.

(Support substrate)
Similar to the sample 101 described above, a transparent substrate having an outer size of 90 mm × 90 mm was prepared as a support substrate for forming the organic EL element. The transparent substrate was then subjected to acetone ultrasonic cleaning, semi-clean ultrasonic cleaning, and ozone cleaning to clean the surface of the substrate.

(First electrode)
Next, the 1st electrode used as the cathode of an organic EL element was formed on the wash | cleaned board | substrate. As the first electrode, an ITO layer having a thickness of 300 nm was formed. The first electrode is approximately 5 Ω / sq. Using a sputtering method. It formed so that it might become a sheet resistance value of a grade.

DC magnetron sputtering was used for sputtering. The substrate was placed under a vacuum level of 90 ° C. and a vacuum level of 1 × 10 ⁻⁴ (Pa), oxygen 2% mixed argon gas was introduced at 0.5 Pa, and 500 W DC was applied to the ITO. An ITO layer was formed on the substrate by adding to the target.

(Insulating layer)
Next, an insulating layer made of polyimide was formed in order to prevent an electrical short in the vicinity of the ITO pattern edge serving as the cathode.
First, the substrate on which the ITO patterning was completed was again subjected to acetone ultrasonic cleaning, semi-clean ultrasonic cleaning, spin drying, and ozone cleaning. Thereafter, polyimide was spin-coated to a thickness of 1 μm. Then, prebaking was performed at 85 ° C. for 3 minutes, and after exposure with an exposure machine, development was performed by immersing in 3% TMAH for 5 minutes. After development, pure water rinsing was performed, and post-baking was performed at 100 ° C. for 80 minutes after spin drying.

(Element isolation)
In addition, an inversely tapered insulating layer serving as a partition wall for element separation between the first light emitting unit and the second light emitting unit of the organic EL element was formed.
This insulating layer was formed by spin-coating polyimide to a thickness of 2.5 μm, pre-baking at 85 ° C. for 3 minutes, exposing with an exposure machine, and then developing by immersing in 3% TMAH for 5 minutes. . After the development, rinsing with pure water was performed, and post-baking was performed at 250 ° C. for 30 minutes after spin drying.
The insulating layer for element isolation has a light emitting area line of the first light emitting unit of 1 mm × 70 mm, a light emitting area line of the second light emitting unit of 2.3 mm × 70 mm, and a space between the first light emitting unit and the second light emitting unit. Was formed into a pattern having a thickness of 60 μm.

(First light emitting functional layer)
Next, a first light-emitting functional layer that emits blue light was formed by vacuum deposition on the first electrode in a region surrounded by the element isolation insulating layer.
First, in order to activate the surface state of the first electrode, UV cleaning was performed for 5 minutes, and then the substrate was put into a vacuum vapor deposition machine and evacuated until a vacuum degree of 1 × 10 ⁻⁵ (Pa) was obtained.
Next, after the evacuation was completed, each layer constituting the first light emitting functional layer was formed by vapor deposition at any time using an evaporation mask in which only the formation region of the first light emitting functional layer was opened.

First, Al was formed to 0.5 nm on the first electrode by EB vapor deposition. Then, 1 nm of LiF was formed as the electron injection layer, and 30 nm of Alq3 was formed as the electron transport layer.
Then, as a light emitting layer, a light emitting dopant having a blue light emitting color and a light emitting host material were deposited by evaporation so as to have a concentration of 3 to 5% of the light emitting dopant.
Furthermore, 50 nm of α-NPD was formed as a hole transport layer, and 30 nm of MoO ₃ was formed as a hole injection layer.

(Second electrode)
Next, a second electrode serving as an anode was formed on the patterned first light emitting functional layer. The second electrode was formed by sputtering IZO so as to cover the first light emitting functional layer. The second electrode was patterned by using C magnetron sputtering for sputtering and using a mask method.

First, the substrate is placed under a degree of vacuum of 1 × 10 ⁻⁴ (Pa), an argon gas mixed with 2.5% oxygen is introduced at 0.75 Pa, and 300 W of DC is applied to the IZO target. Thus, an IZO electrode was formed on the first light emitting functional layer. The second electrode has an IZO sheet resistance value of approximately 6 Ω / sq. Designed to be about.
The second electrode was taken out on one side of the substrate.

(Second light emitting functional layer, third light emitting functional layer)
Next, a second light emitting functional layer emitting green light and a third light emitting functional layer emitting red light were formed on the second electrode. The second light-emitting functional layer and the third light-emitting functional layer were each formed in a strip shape on the second electrode by being separately applied using a vapor deposition mask.
The second light emitting functional layer was formed so that the light emitting area line was 1 mm × 70 mm. The third light emitting functional layer was formed so that the light emitting area line was 2.3 mm × 70 mm. The space between the second light emitting functional layer and the third light emitting functional layer was formed to be 60 μm.

First, using a vapor deposition mask capable of simultaneously forming the light emitting region of the second light emitting functional layer and the light emitting region of the third light emitting functional layer, MoO ₃ was formed to 30 nm as a hole injection layer. Next, 30 nm of α-NPD was formed as a hole transport layer.

Next, 30 nm of Alq3 was formed as an electron transport layer using a vapor deposition mask capable of simultaneously forming the light emitting region of the second light emitting functional layer and the light emitting region of the third light emitting functional layer. Next, 1 nm of LiF was formed as an electron injection layer.

(Third electrode)
Next, a third electrode serving as a cathode was formed on the second light emitting functional layer and the third light emitting functional layer. As the third electrode, an Al layer having a thickness of 150 nm was formed by EB vapor deposition. For forming the third electrode, an opening capable of simultaneously forming the light emitting regions of the second light emitting functional layer and the third light emitting functional layer, and an opening of the lead routing portion to the end of the substrate for electrical connection of the third electrode A vapor deposition mask having the following was used.

(Sealing)
Next, the first light-emitting unit and the second light-emitting unit were sealed in the same manner as in the above-described sample 101, and a sample 102 of an organic EL element was manufactured.

(Organic EL device)
In the sample 102 manufactured through the above steps, IZO, which is a transparent electrode, was formed by a sputtering method using the second electrode as a common anode. Since the second electrode was used as a common anode and a transparent oxide electrode having high transmittance was formed, an organic EL device having good transmittance and luminous efficiency was produced.
The organic EL element of Sample 102 thus manufactured had an aperture ratio of 93% for the blue light emitting region, 28% for the green light emitting region, and 64% for the red light emitting region.

[Production of Organic EL Element of Sample 103]
A sample 103 of the organic EL element having the configuration shown in FIG. 5 was prepared as follows.

(Support substrate to second electrode)
First, a first electrode serving as an anode, an insulating layer, a first light emitting functional layer, and a second electrode serving as a cathode and an anode were formed on a supporting substrate using a method similar to that of the sample 101 described above.

First, the second light emitting functional layer, the third light emitting functional layer, and the second light emitting functional layer are formed on the second electrode using an evaporation mask capable of simultaneously forming the light emitting region of the second light emitting functional layer and the light emitting region of the third light emitting functional layer. As a common hole injection layer, MoO ₃ was formed to a thickness of 30 nm. Next, using the same vapor deposition mask, 30 nm of α-NPD was formed as a hole transport layer.

Next, a common electron transporting layer for the second light emitting functional layer and the third light emitting functional layer using a vapor deposition mask capable of simultaneously forming the light emitting region of the second light emitting functional layer and the light emitting region of the third light emitting functional layer As a result, 30 nm of Alq3 was formed. Next, 1 nm of LiF was formed as an electron injection layer using the same vapor deposition mask.

(3rd electrode to sealing)
Next, after the third electrode was formed using a method similar to that of the sample 101 described above, the formed light emitting unit was sealed using a method similar to the sample 101 described above.

(Organic EL device)
Through the above steps, a sample 103 of the organic EL element was produced.
In the sample 103, the first electrode serves as an anode with respect to the first light emitting functional layer. The second electrode serves as a cathode for the first light emitting functional layer and serves as an anode for the second light emitting functional layer and the third light emitting functional layer. The third electrode serves as a cathode for the first light emitting functional layer.

In sample 103, the first light-emitting functional layer was formed on the first electrode by a normal stacking in which a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer were stacked in this order. In addition, the second light-emitting functional layer and the third light-emitting functional layer were formed in a normal stack in which a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer were stacked in this order on the second electrode. .
As described above, in the sample 103, the first light-emitting functional layer, the second light-emitting functional layer, and the third light-emitting functional layer are both formed in a normal stack.

The organic EL element of Sample 103 thus produced had an aperture ratio of 95% for the blue light emitting region, 28% for the green light emitting region, and 64% for the red light emitting region.

[Production of Organic EL Element of Sample 104]
A sample 104 of the organic EL element having the configuration shown in FIG. 1 was prepared as follows. Note that the sample 104 has a structure in which an insulating layer for element isolation is removed from the structure shown in FIG.

(Support substrate to insulating layer)
Using a method similar to that of the sample 102 described above, an insulating layer was formed on the supporting substrate in order to prevent a first electrode serving as a cathode and an electrical short circuit near the pattern edge of the first electrode.

(First light emitting functional layer)
Next, a first light emitting functional layer was formed on the first electrode by vacuum deposition.
First, in order to activate the surface state of the first electrode, UV cleaning was performed for 5 minutes, and then the substrate was put into a vacuum vapor deposition machine and evacuated until a vacuum degree of 1 × 10 ⁻⁵ (Pa) was obtained.
Next, after completing the evacuation, each layer constituting the first light emitting functional layer was formed by vapor deposition as needed using a vapor deposition mask having only the formation region of the first light emitting functional layer opened.

In the first light emitting functional layer, the light emitting area line of the first light emitting unit is 1 mm × 70 mm, the light emitting area line of the second light emitting unit is 2.3 mm × 70 mm, and there is a space between the first light emitting unit and the second light emitting unit. It formed in the pattern used as 60 micrometers.

First, Al was formed to 0.5 nm on the first electrode by EB vapor deposition. Then, 1 nm of LiF was formed as the electron injection layer, and 30 nm of Alq3 was formed as the electron transport layer.
Then, as a light emitting layer, a light emitting dopant having a blue light emitting color and a light emitting host material were deposited to a thickness of 3 to 5% so as to have a concentration of 3-5%.
Furthermore, 50 nm of α-NPD was formed as a hole transport layer, and 30 nm of MoO ₃ was formed as a hole injection layer.

(Second electrode to sealing)
Next, a second electrode serving as an anode was formed on the patterned first light-emitting functional layer using a method similar to that of the sample 102 described above. Further, a second light emitting functional layer that emits green light is formed on the second electrode of the first light emitting unit using the same method as that of the sample 102 described above, and red light is emitted on the second electrode of the second light emitting unit. A third light emitting functional layer was formed.

Next, after the third electrode is formed on the second light emitting functional layer and the third light emitting functional layer using the same method as that of the sample 102 described above, the formed light emitting unit is similar to the sample 101 described above. Sealed using the method.

(Organic EL device)
Through the above steps, a sample 104 of the organic EL element was produced.
The sample 104 has a structure in which an insulating layer serving as a partition wall for element isolation is removed from the sample 102 described above.
The organic EL element of Sample 104 thus produced had an aperture ratio of 93% for the blue light emitting region, 28% for the green light emitting region, and 64% for the red light emitting region.

[Production of Organic EL Element of Sample 105]
A sample 105 of an organic EL element was produced using the following conventional method. In sample 105, each color light emitting layer of RGB was formed by a conventionally known vapor deposition coating method.

First, an ITO layer was patterned as a first electrode on a support substrate in a strip shape. The cleaning of the support substrate, the formation of the ITO layer, the patterning of the ITO layer, and the formation of the insulating film at the pattern edge of the ITO layer were performed in the same manner as in the sample 101 described above.

In the patterning of the first electrode, in consideration of the luminous efficiency and lifetime of each light emitting functional layer, the aperture ratio was determined so that the lifetime of each color was the same, and the first electrode was formed with dimensions based on this aperture ratio. The pattern of the first light emitting functional layer that emits blue light is 2.5 mm × 70 mm, the second light emitting functional layer that emits green light is 500 μm × 70 mm, and the third light emitting functional layer that emits red light is 1000 μm × 70 mm. Was formed as 20 μm.

In addition, the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer have the same structure as each light-emitting functional layer, and the above-described sample 101 is formed using a vapor deposition mask having openings that can be formed simultaneously. The second light emitting functional layer and the third light emitting functional layer were formed by the same method.
Further, a second electrode made of Al was formed on each light emitting functional layer using the same method as the formation of the third electrode of the sample 101 described above.

Through the above steps, a sample 105 of the organic EL element was produced.
The manufactured organic EL element of Sample 105 had an aperture ratio of 58% in the blue light emitting region, an aperture ratio in the green light emitting region of 12%, and an aperture ratio in the red light emitting region of 23%.

[Production of Organic EL Element of Sample 106]
A sample 106 of an organic EL element was produced using the following conventional method. In the sample 106, each color light emitting layer of RGB was formed by a method of vertically stacking on a conventionally known transparent substrate.

Next, a first light emitting functional layer emitting blue light was formed on the first electrode.
The first light-emitting functional layer has, in order from the first electrode side, 30 nm of MoO ₃ as a hole injection layer, 50 nm of α-NPD as a hole transport layer, 30 nm of a blue light-emitting layer, 30 nm of Alq3 as an electron transport layer, As an injection layer, 1 nm of LiF was formed.
Next, Al was formed as a second electrode with a thickness of 10 nm on the first light emitting functional layer using an EB vapor deposition method.

Next, a second light emitting functional layer that emits green light was formed on the second electrode.
The second light emitting functional layer has, in order from the second electrode side, 30 nm of MoO ₃ as the hole injection layer, 30 nm of α-NPD as the hole transport layer, 30 nm of the green light emitting layer, 30 nm of Alq3 as the electron transport layer, As an injection layer, 1 nm of LiF was formed.
Next, Al was formed as a third electrode with a thickness of 10 nm on the second light emitting functional layer using an EB vapor deposition method.

Next, a third light emitting functional layer that emits red light was formed on the third electrode.
The third light emitting functional layer is, in order from the third electrode side, 30 nm of MoO ₃ as a hole injection layer, 30 nm of α-NPD as a hole transport layer, 30 nm of a green light emitting layer, 30 nm of Alq3 as an electron transport layer, As an injection layer, 1 nm of LiF was formed.
Next, Al was formed as a fourth electrode with a thickness of 150 nm on the third light emitting functional layer using an EB vapor deposition method.

Through the above steps, a sample 106 of the organic EL element was produced.
The organic EL element of the produced sample 106 had an aperture ratio of 95% for the blue, red, and green light emitting regions.

[Evaluation of Samples in Examples]
The samples 101 to 106 prepared as described above were measured for luminous efficiency, half life, chromaticity, and sensory evaluation. The results are shown in Table 1 below.

[Luminescence efficiency]
The luminous efficiency of this evaluation is the result of measuring each color under the actual driving condition of 1,000 cd / m ^{2 in} a room temperature environment.

[Half life]
The half life in this evaluation indicates a life result in which the luminance is reduced by half with respect to the initial luminance when actually driven in a room temperature environment.

[Chromaticity]
The chromaticity in this evaluation indicates the chromaticity when red, blue, and green are individually emitted under the actual driving conditions.

[sensory evaluation]
The sensory evaluation of this evaluation is the result of evaluating the visibility of appearance when RGB and white which is a mixed color are displayed to 10 people.

[Evaluation results of Examples]
As shown in Table 1, when comparing the organic EL elements of Samples 101 to 104 with the organic EL elements of Samples 105 to 106, the organic EL elements of Samples 101 to 104 have good luminous efficiency and chromaticity. The lifetime was long, and good results were obtained even in sensory evaluation accompanying visual recognition.

In the organic EL element of Sample 105, the simple coloring method according to the conventional example is adopted, so that the chromaticity is good, but the lifetime is reduced because the luminance required for each light emitting layer is increased. In particular, the lifetime of a blue light-emitting layer using a fluorescent material with low emission efficiency is lower than that of the organic EL elements of Samples 101 to 104.

Further, in the organic EL element of Sample 105, the green light emitting layer is 500 μm, which is narrower than the blue light emitting layer of 2.5 mm and the red light emitting layer of 1000 μm. An unfavorable result was obtained in the sensory evaluation.

In the organic EL element of the sample 106, since each light emitting functional layer is formed by stacking, each light emitting layer has the same area and a large aperture ratio. For this reason, although the sensory evaluation of visibility was preferable, it was confirmed that the color change, the light emission efficiency was lowered, and the life was lowered depending on the light emission efficiency of each light emitting layer.

On the other hand, the organic EL element of the sample 101 has 95, 28, and 64% aperture ratios in the blue, green, and red emission regions, and can sufficiently compensate for the difference in emission efficiency between blue, green, and red. . For this reason, the lifetime of each light emitting layer can be improved. In particular, it is possible to improve the lifetime of the blue light emitting layer and suppress the decrease in light emission efficiency.

Similarly, in the organic EL elements of Samples 102 to 104, the aperture ratio of the blue light emitting layer is large, and the difference in light emission efficiency can be sufficiently compensated. For this reason, the lifetime of each light emitting layer can be improved and the fall of luminous efficiency can be suppressed.

From the above results, the organic EL device using the configuration of the present invention can improve the aperture ratio of the light emitting layer with low light emission efficiency, and thus suppress the improvement of the life of the light emitting layer and the decrease of the light emission efficiency. Can do. Accordingly, it is possible to suppress a decrease in luminance of the organic EL element.

Note that the present invention is not limited to the configuration described in the above embodiment, and various modifications and changes can be made without departing from the configuration of the present invention.

11, 31, 41... 1st light emitting functional layer, 12, 32, 42... 2nd light emitting functional layer, 13, 33, 43... 3rd light emitting functional layer, 14, 34, 44.

1st electrode

15, 35, 45 ... 2nd electrode, 16, 36, 46 ... 3rd electrode, 17, 37, 48 ... Insulating layer, 18 ... 1st light emission unit, 19 * ..Second light emitting unit, 20 ... support substrate, 38 ... switch, 39,49 ... light emitting unit, 47 ... fourth electrode

Claims

A first electrode;
A first light emitting functional layer provided on the first electrode;
A second electrode provided on the first light emitting functional layer;
A second light emitting functional layer provided on the second electrode;
A third electrode provided on the second light emitting functional layer,
The first electrode and the third electrode are electrodes of the same polarity;
The organic electroluminescence element, wherein the second electrode is an electrode having a polarity opposite to that of the first electrode and the third electrode.
2. The organic electroluminescence device according to claim 1, further comprising a third light emitting functional layer on the second electrode at a position different from the second light emitting functional layer, and the third electrode provided on the third light emitting functional layer. .
The organic electro according to claim 2, wherein the common first electrode, the first light emitting functional layer, and the second electrode are provided for the second light emitting functional layer and the third light emitting functional layer. Luminescence element.
A first light emitting unit and a second light emitting unit;
The first light emitting unit includes the first electrode, the first light emitting functional layer, the second electrode, the second light emitting functional layer, and the third electrode;
The organic electroluminescent element according to claim 2, wherein the second light emitting unit includes the first electrode, the first light emitting functional layer, the second electrode, the third light emitting functional layer, and the third electrode.
An electrode having a third light emitting functional layer provided on the third electrode and a fourth electrode provided on the third light emitting functional layer, wherein the first electrode and the third electrode have the same polarity. The organic electroluminescent element according to claim 1, wherein the second electrode and the fourth electrode are electrodes having opposite polarities to the first electrode and the third electrode.
A first electrode;
A first light emitting functional layer provided on the first electrode;
A second electrode provided on the first light emitting functional layer;
A second light emitting functional layer provided on the second electrode;
A third light emitting functional layer provided on the second electrode at a position different from the second light emitting functional layer;
A third electrode provided on the second light emitting functional layer and the third light emitting functional layer;
With
The first electrode and the third electrode are electrodes of opposite polarities;
The organic electroluminescence element in which the second electrode is an electrode having a polarity opposite to that of the first light emitting functional layer, the second light emitting functional layer, and the third light emitting functional layer.
An electronic apparatus comprising the organic electroluminescence element according to any one of claims 1 to 6.