JP2006024711A - Organic electroluminescence element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize high transportation efficiency for a positive hole and an electron, and excellent light emitting characteristics with a simplified structure. <P>SOLUTION: An organic electroluminescence element comprises at least an organic thin film 3 formed between an positive electrode 2 and an anode electrode 4, wherein the organic thin film 3 comprises a single host material layer and a plurality of different kinds of dopants which are doped to the single host material layer with a distribution in the film thickness direction. One of the dopants is a dopant 12 which is provided with light emitting characteristics, and the others are a dopant 11 provided with positive hole implanting characteristics and/or positive hole transport characteristics, and a dopant 13 provided with electron implanting characteristics and/or electron transport characteristics. The manufacturing method has a step of sequentially forming in the film thickness direction of the host material layer a positive hole dopant region where the dopant 11 is implanted which is provided with the positive the positive hole implanting characteristics and/or positive hole transport characteristics, a light emitting region where the dopant 12 is doped which is provided with the light emitting characteristics, and an electron dopant region where the dopant 13 provided with the electron implanting characteristics and/or electron transport characteristics is doped. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic electroluminescent device comprising an organic thin film doped with a dopant with respect to a single host material layer.

  An organic electroluminescence (hereinafter referred to as “organic EL”) element is a self-luminous planar light source and is relatively easy to increase in size and flexibility. Therefore, it can be applied to a wide range of fields such as lighting devices and displays. Is expected.

  The basic structure of an organic EL element is called a single-layer structure in which a single-layer organic thin film in which a light-emitting material is uniformly distributed is sandwiched between a cathode and an anode, and efficiently transports holes and electrons. It is usually extremely difficult to realize an organic electroluminescence device having all the characteristics of obtaining excellent light emission characteristics with such a single layer structure.

  Therefore, as shown in FIG. 9, the organic EL element includes an organic thin film 104 sandwiched between an anode 102 and a cathode 103 formed on a glass substrate 101, for example, a hole injection layer 105 and a hole transport layer 106. In general, the light emitting layer 107, the electron transport layer 108, and the electron injection layer 109 are stacked in this order. By separating functions such as charge transport or light emission for each layer constituting the organic thin film 104 and selecting an optimum material according to the purpose of each layer, the characteristics of the organic EL element are improved over the entire multilayer structure. Yes.

As organic thin films of organic EL elements, various structures and compositions have been proposed so far. For example, an organic EL in which the light emitting material doping amount is changed in the thickness direction of the light emitting layer. An element has been proposed (see, for example, Patent Document 1).
JP 2003-229272 A

  By the way, an organic material has an inherent energy level (HOMO level and LUMO level), and the energy level is similar to an organic thin film having a multilayer structure in which layers of different organic materials are laminated as shown in FIG. In organic thin films in which layers with different levels are stacked, energy offsets and energy barriers occur at the interface between the layers, preventing charge injection and transport, increasing the light emission threshold voltage of the device, and increasing the amount of heat generation Cause various problems.

  Further, for example, when an organic thin film having a multilayer structure is formed by a vapor deposition method, a vacuum chamber for vapor deposition is required for each organic material (layer). For example, when forming a five-layer organic thin film 104 by vapor deposition as shown in FIG. 9, a large-scale and expensive film-forming apparatus having five vacuum chambers is usually required. The manufacturing cost is significantly increased. In addition, it takes time to move the substrate between the vacuum chambers and to put the substrate in and out of each vacuum chamber, and there is a problem that the production efficiency at the time of mass production is poor. This also raises the manufacturing cost.

  In Patent Document 1, there is a description about changing the doping amount of the dopant in the light emitting layer in the thickness direction, but it is assumed that the organic thin film is a multilayer and the function is separated into each layer. For example, in order to increase the charge transport efficiency, it is necessary to additionally form another layer in addition to the light emitting layer, which may increase the manufacturing cost.

  Therefore, the present invention has been proposed in view of such conventional circumstances, and provides an organic electroluminescence device capable of improving charge transport efficiency with a simple structure and obtaining excellent light emission characteristics. For the purpose.

  In order to solve the above-mentioned problems, an organic electroluminescent device according to the present invention is an organic electroluminescent device in which at least an organic thin film is formed between an anode and a cathode, and the organic thin film is a single host material. A plurality of types of dopants different from each other in the layer are doped with distribution in the film thickness direction.

  In addition, one of the dopants is a dopant that imparts light emission characteristics, and the other dopant has any one of hole injection characteristics and / or hole transport characteristics, electron injection characteristics, and / or electron transport characteristics. It is the dopant to provide, It is characterized by the above-mentioned.

  Furthermore, in the film thickness direction of the host material layer, a hole dopant region in which a dopant imparting hole injection properties and / or hole transport properties is implanted, a light emitting region doped with a dopant imparting light emission properties, and An electron dopant region doped with a dopant imparting electron injection characteristics and / or electron transport characteristics is formed sequentially.

  In the organic electroluminescence device of the present invention, the characteristics of each dopant are given in the film thickness direction of one organic thin film by changing the type and concentration distribution of the dopant in the film thickness direction of a single host material layer. Areas are formed. At this time, the host material which is the main component of the organic thin film is common to the entire organic thin film. For example, a dopant that imparts hole injection characteristics and / or hole transport characteristics, a dopant that imparts light emission characteristics, a dopant that imparts electron injection characteristics and / or electron transport characteristics, and the like have a distribution in the film thickness direction of the organic thin film. By doping, a region having a function corresponding to a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, or the like is formed in one organic thin film. For this reason, an organic electroluminescence device excellent in both charge injection and / or transport efficiency and light emission characteristics can be realized without dividing the organic thin film into a multilayer structure. That is, in the organic electroluminescence element of the present invention, the function that has been realized in the past by the organic thin film having a multilayer structure is realized by an organic thin film having a simple layer structure such as a single layer structure.

  Further, it is preferable that the light emitting region and at least one of the hole dopant region or the electron dopant region partially overlap in the film thickness direction. By arranging the dopants so that the distributions of the respective dopants partially overlap, charge transport is achieved more efficiently.

  In addition, the above-mentioned invention of Patent Document 1 only changes the doping amount of the dopant inside the light emitting layer, and by doping a single host material layer with a plurality of types of dopants, The idea is fundamentally different from the present invention that creates regions corresponding to a hole injection layer and / or a hole transport layer, a light emitting layer, an electron injection layer, and / or an electron transport layer.

  According to the present invention, a plurality of different types of dopants are doped with a distribution in the film thickness direction with respect to a single host material layer, so that, for example, a light-emitting dopant region, a hole dopant region, or an electron dopant region is organic. Since it is formed in the film thickness direction of the thin film, it is possible to provide an organic electroluminescence device that is excellent in both charge transport efficiency and light emission characteristics, without forming the organic thin film into a multilayer structure. In addition, since the organic thin film does not have to have a multilayer structure, the influence of energy offset and energy barrier caused by stacking layers of different organic materials can be suppressed, the light emission threshold voltage is low, and the organic electroluminescence has a small calorific value. An element can be provided. In addition, according to the present invention, the structure of the organic thin film becomes very simple, so that the number of vacuum chambers required for forming the organic thin film can be reduced, and the decrease in production efficiency can be suppressed. The manufacturing cost of the luminescence element can be greatly reduced.

  Hereinafter, an organic electroluminescence (hereinafter referred to as organic EL) element to which the present invention is applied will be described in detail with reference to the drawings.

  Fig.1 (a) is sectional drawing of the organic EL element to which this invention is applied. As shown in FIG. 1A, an organic EL element is formed on a substrate 1 made of a transparent insulating material such as glass, an anode 2 made of a transparent conductive material such as ITO (indium tin oxide), and an organic material. An organic thin film 3 and a cathode 4 made of a metal such as Al are laminated in this order, and these are sealed by a sealing film (not shown) or the like. In this organic EL element, light emitted from the organic thin film 3 is extracted from the back surface of the substrate 1 of the organic EL element.

  The organic thin film 3 is configured by doping a single host material layer with a plurality of types of dopants with distribution in the film thickness direction. The host material that is the main component of the organic thin film 3 is common to the entire region of the organic thin film 3. FIG. 1B is a schematic diagram showing, for example, the concentration distribution of three types of dopants in the organic thin film 3, where the horizontal axis indicates the dopant concentration and the vertical axis indicates the film thickness direction of the organic thin film. As shown in FIG. 1B, the organic thin film 3 is doped with a dopant (hereinafter referred to as a hole dopant) 11 imparting hole injection characteristics and / or hole transport characteristics from the anode 2 side. A hole dopant region, a light-emitting dopant region imparted with light-emitting properties (hereinafter referred to as light-emitting dopant) 12, and a dopant that imparts electron injection properties and / or electron transport properties (hereinafter referred to as electronic dopants). .) 13 has an electron dopant region doped, and doped regions of each dopant are sequentially formed in the film thickness direction.

  Each dopant has a concentration distribution that continuously changes in the film thickness direction. For example, the hole dopant 11 and the electron dopant 13 in FIG. 1B are doped with a concentration distribution such that the concentration is highest at the interface with the electrode and gradually decreases toward the counter electrode. Further, the light emitting dopant 12 is doped with a concentration distribution such that the concentration gradually decreases toward the cathode 2 and the anode 4 with the high concentration region as the center.

  In the organic EL device of the present invention, for example, as shown in FIG. 1B, the distribution of the hole dopant 11 and the distribution of the light emitting dopant 12 partially overlap, and the distribution of the light emitting dopant 12 and the distribution of the electron dopant 13. Are arranged so that they partially overlap. A single host material that is the main component of the organic thin film is used, and the light emitting region and at least one of the hole dopant region or the electron dopant region partially overlap in the film thickness direction, that is, the distribution of each dopant is appropriately overlapped. As a result, the effects of energy offset and energy barrier can be reliably suppressed. By appropriately setting the overlapping degree of each region, the charge transport efficiency can be further increased, the light emission threshold voltage of the organic EL element can be lowered, and the amount of heat generation can be reduced. The degree of overlapping of the concentration distributions of the respective dopants is appropriately determined according to the type of dopant. If the dopant distribution is not overlapped, the region where the dopant concentration is zero may act as an interface in the organic thin film, and an energy barrier may be created to hinder charge transport.

  As the host material, basically, a material having a wide energy gap, for example, a material having a band gap of 2.7 eV or more is preferable. As a specific host material, 4,4 ′, 4 ″ -tris [N- (1-naphthyl) -N-phenylamino] -triphenylamine (2-TNATA: 4,4 ′, 4 ″- tris [N- (1-naphthyl) -N-phenylamino] -triphenylamine), N, N′-di (naphthalen-1-yl) -N, N′diphenyl-benzidine (NPD: N, N′-Di (naphthalen) -1-yl) -N, N'diphenyl-benzidine), 4,4'-bis (carbazol-9-yl) biphenyl (CBP: 4,4'-Bis (carbazol-9-yl) biphenyl) It is done. A host material having such a wide energy gap has a high glass transition point of, for example, 80 ° C. or more and is stable against heat. Therefore, by using such a host material as the main component of the organic thin film 3, an organic EL element having excellent thermal stability is realized.

  In addition, in the conventional organic EL element in which the organic thin film has a multilayer structure, since the function is separated in each layer, the use of a material having a narrow energy gap according to the characteristics of each layer is assumed. The use of such a material having a wide energy gap was hardly expected. In general, since a material having a narrow energy gap has low thermal stability, a conventional organic EL element using the material for an organic thin film has a problem in heat resistance.

  As the hole dopant 11, tetrafluorotetracyanoquinodimethane (F4-TCNQ: tetrafluorotetracyanoquinodimethane), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ: 2,3-dichrolo-5, 6-dicyano-1,4-benzoquinone), 7,7,8,8-tetracyanoquinodimethane (TCNQ: 7,7,8,8-tetracyanoquinodimethane), 1,4,5,8-naphthalene-tetracarboxylic Acid dianhydride (NTCDA: 1,4,5,8-naphthalene-tetracaboxylic-dianhydride), perylene-3,4,9,10-tetracarboxylic acid-3,4,9,10-dianhydride (PTCDA: perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride). Among them, it is preferable to use F4-TCNQ, DDQ, or the like as a dopant imparting hole injection characteristics. Moreover, as a dopant which provides a hole transport characteristic, it is preferable to use F4-TCNQ, PTCDA, or the like.

  In the conventional organic EL element having a multilayer structure, it is necessary to form an organic thin film between the electrodes very thinly in order to avoid an increase in resistance value. In this case, the organic EL element is adversely affected by the ITO spike used for the anode, There are inconveniences such as a reduction in luminous efficiency because the light resonance effect cannot be obtained. On the other hand, in the present invention, even when the organic thin film 3 is made thicker than before by using a charge transfer complex such as TCNQ as the hole dopant 11 and thickening the region doped with this dopant. The increase in the resistance value of the organic thin film 3 is suppressed. For this reason, since the organic thin film of an organic EL element can be thickened compared with the past, the influence of the spike of the anode 2, etc. can be reduced. In addition, since the organic film of the organic EL element can be made thicker than in the past, it is easy to design the organic thin film 3 with a film thickness having a light resonance structure, and the attenuation of light emission can be suppressed. Efficiency can be increased.

  Examples of the luminescent dopant 12 include rubrene (orange), perylene (blue), [7-diethylamino-3- (2-thienyl) chromen-2-ylidene] -2,2-dicyanovinylamine (ACY: [7-diethylamino- 3- (2-thienyl) chromen-2-ylidene] -2,2-dicyanovinylamine) (red), 7,16-dihydro-7,16-dimethylbenzo [a] benzo [5,6] quino [3,2 -I] acridine-9,18-dione (QD: (7,16-dihydro-7,16-dimethylbenzo [a] benzo [5,6] quino [3,2-I] acridine-9,18-dion) (Green), coumarin (red to blue), a mixture of these dopants, and the like can be used.

  Examples of the electron dopant 13 include alkali metals such as Cs (cesium), Li (lithium), K (potassium), Na (sodium), and Rb (rubidium), alkaline earth metals, bis (ethylenedithio) tetrathiafulvalene (BEDT). Organic compounds such as -TFF: bis (ethylenedithio) tetrathiafulvalene) can be used. Among them, Cs or the like is preferably used as a dopant that imparts electron injection characteristics. In addition, BEDT-TFF is preferably used as a dopant that imparts electron transport properties.

  As described above, in the organic EL device, the hole dopant 11, the light emitting dopant 12, and the electron dopant 13 are doped with distribution in the film thickness direction, and the hole dopant region, the light emitting dopant region, and the electron dopant region are anodes. By providing in order from the second side, for example, a hole injection and / or hole transport layer, a light emitting layer, and a region corresponding to the electron injection and / or electron transport layer are formed in the organic thin film 3. Since a region for improving hole injection and / or hole transport efficiency, electron injection and / or electron transport efficiency and a region having excellent light emission characteristics are formed, the hole and electron injection efficiency and transport efficiency are excellent. An organic EL element having excellent light emission characteristics can be realized with an organic thin film having a very simple structure. At this time, since the host material layer is a single layer, there is no unnecessary interface as in the conventional organic thin film having a multilayer structure, and the influence of energy offset and energy barrier can be reduced. Therefore, an organic EL element with a low driving voltage and a small calorific value is realized. Further, by partially overlapping each dopant region in the film thickness direction, the charge transport efficiency can be further improved.

  The organic thin film of the organic EL element as described above is formed by a vapor phase method, for example, a vapor deposition method. For forming an organic thin film by vapor deposition, for example, a crucible 51a for a host material, a crucible 51b for a light emitting dopant, and a hole dopant for a hole dopant in a vacuum chamber (not shown) as shown in FIG. A film forming apparatus including a crucible 51c and an electron dopant crucible 51d can be used. In the vicinity of the opening of each crucible 51a, 51b, 51c, 51d, there are provided shutters 52a, 52b, 52c, 52d for controlling the vapor deposition rate of the material contained in the crucible 51, and for controlling the film thickness and vapor deposition rate. Crystal oscillation sensors 53a, 53b, 53c, and 53d. Each crucible 51 is partitioned by a partition wall 54.

  When an organic thin film is formed using such a film forming apparatus, the inside of the vacuum chamber into which the substrate 1 on which the anode 2 made of ITO or the like is formed is brought into a predetermined reduced pressure state, and the substrate 1 is rotated. However, the material in each crucible 51 is vapor-deposited on the anode 2, and a host material and a dopant are co-evaporated. At this time, the shutter 52a corresponding to the crucible 51a for the host material is kept open, and the deposition of the host material is maintained. Then, by controlling the opening and closing of the shutters 52b, 52c, and 52d while depositing the host material, the hole dopant 11, the light emitting dopant 12, and the electron dopant 13 are arranged so that the distribution of each dopant partially overlaps. By sequentially depositing, an organic thin film 3 having each region as shown in FIG. 1B is formed.

  As described above, the formation of the organic thin film of the organic EL element can be realized only by controlling the deposition timing of the dopant by opening and closing the shutter, for example, in one vacuum chamber. For this reason, 3 to 5 vacuum chambers are required in the manufacture of the conventional organic thin film, whereas in the present invention, a small number of vacuum chambers such as 1 or 2 may be used. The organic EL element can be manufactured at a very low cost. In addition, since the number of vacuum chambers can be reduced, the time for moving the substrate in and out of the vacuum chamber and the time for moving the substrate between the vacuum chambers can be greatly shortened, and the production efficiency during mass production can be increased. The manufacturing cost of the EL element can be further reduced.

  In the above description, the organic thin film 3 has a single layer structure, and the three regions of the region doped with the hole dopant 11, the region doped with the light emitting dopant 12, and the region doped with the electron dopant 13 are organic. Although the organic EL element formed in the thin film 3 was mentioned as an example, this invention is not limited to this.

  For example, as the light emitting dopant 12, in addition to using the dopant alone as shown in FIG. 1B, a plurality of kinds of dopants may be used to obtain light emission of an arbitrary color. For example, in order to obtain white light emission, as shown in FIG. 3, as a light emission dopant, a dopant 12R that gives red (R) light emission, a dopant 12G that gives green (G) light emission, and blue (B) light emission are given. This is realized by mixing and using the dopant 12B. In addition, as shown in FIG. 4, white light emission includes a dopant 12R that imparts red (R) light emission, a dopant 12G that imparts green (G) light emission, and a dopant 12B that imparts blue (B) light emission, It is also realized by doping so that the dopant distribution partially overlaps in the film thickness direction. Note that the color of light emitted from the light-emitting dopant region is not limited to the above-described white example, and a desired color can be emitted by appropriately selecting the type of dopant. Further, the combination of dopant colors and the arrangement order of the dopants are not limited to the above examples.

  In the organic EL device of the present invention, for example, as shown in FIG. 5, two types of dopants, that is, a metal dopant 14 and an organic dopant 15 are used as the electron dopant 13 and the metal dopant 14 is doped. It is preferable that a region doped with the organic dopant 15 is disposed between the region doped with the light emitting dopant 12. Considering the injectability of electrons from the cathode 4, it is preferable to use the metal dopant 14 as the electron dopant 13, but when the distribution of the metal dopant 14 is partially overlapped with the distribution of the light emission dopant 12, it is generated in the light emission dopant region. This is because part of the energy may be converted into heat and the luminous efficiency may decrease.

  Further, the configuration of the organic thin film 3 is not limited to an example in which three regions of a region doped with the hole dopant 11, a region doped with the light emitting dopant 12, and a region doped with the electron dopant 13 are formed. For example, as shown in FIG. 6, two types of dopants, a dopant (hole injection dopant) 16 excellent in hole injection property and a dopant (hole transport dopant) 17 excellent in hole transport property, as the hole dopant 11. And four regions may be formed in the organic thin film 3 by arranging so that the distribution of each dopant partially overlaps. Moreover, as shown in FIG. 7, two types of dopants, ie, a dopant (electron injection dopant) 18 excellent in electron injection property and a dopant (electron transport dopant) 19 excellent in electron transport property are used as the electron dopant 13, Four regions may be formed in the organic thin film 3 by arranging so that the distributions of the respective dopants partially overlap. Further, as shown in FIG. 8, a hole injection dopant 16 and a hole transport dopant 17 are used as the hole dopant 11, an electron injection dopant 18 and an electron transport dopant 19 are used as the electron dopant 13, and five regions are formed in the organic thin film 3. May be formed. By forming a region in which the functions are more finely separated in the film thickness direction of the organic thin film 3, the charge injection and transport efficiency of the organic thin film 3 can be further increased, and the characteristics of the organic EL element can be further improved.

  In the organic EL device of the present invention, a layer other than the organic thin film may be disposed between the anode and the cathode. For example, an electron transport layer and / or an electron injection layer may be added between the organic thin film and the cathode. In this case, in the organic thin film, the hole dopant and the light emitting dopant are doped with different concentration distributions in order from the anode side. Further, a hole transport layer and / or a hole injection layer may be added between the organic thin film and the anode. In this case, in the organic thin film, the light emitting dopant and the electron dopant are doped with different concentration distributions in order from the anode side.

  In the above-described embodiment, an organic EL element having a structure in which the anode (transparent electrode) 4, the organic thin film 3, and the cathode 4 are laminated in this order on the substrate 2 and light emission is extracted from the back surface of the substrate 2 is taken as an example. Although described, the present invention is not limited to this. For example, the present invention can be applied to a so-called top emission type organic EL element in which, for example, a cathode, an organic thin film, and an anode (transparent electrode) are laminated in this order on a substrate and light emission is taken out from the anode side.

  Moreover, the apparatus which can apply the organic EL element of this invention is not specifically limited, For example, it can apply to a display, an illuminating device, etc.

(A) is a schematic sectional drawing which shows an example of the organic EL element to which this invention is applied, (b) shows the dopant concentration distribution in the film thickness direction of the organic thin film of the organic EL element shown to (a). It is a figure shown typically. It is a perspective view which shows the inside of the vacuum chamber of the film-forming apparatus for forming an organic thin film. It is another example of the organic EL element to which this invention is applied, and is a figure which shows typically the dopant concentration distribution in the film thickness direction of an organic thin film. It is another example of the organic EL element to which this invention is applied, and is a figure which shows typically the dopant concentration distribution in the film thickness direction of an organic thin film. It is a further example of the organic EL element to which this invention is applied, and is a figure which shows typically the dopant concentration distribution in the film thickness direction of an organic thin film. It is a further example of the organic EL element to which this invention is applied, and is a figure which shows typically the dopant concentration distribution in the film thickness direction of an organic thin film. It is a further example of the organic EL element to which this invention is applied, and is a figure which shows typically the dopant concentration distribution in the film thickness direction of an organic thin film. It is a further example of the organic EL element to which this invention is applied, and is a figure which shows typically the dopant concentration distribution in the film thickness direction of an organic thin film. It is a schematic sectional drawing which shows an example of the conventional organic EL element.

Explanation of symbols

1 substrate, 2 anode, 3 organic thin film, 4 cathode, 11 hole dopant, 12 light emitting dopant, 13 electron dopant, 14 metal dopant, 15 organic dopant, 16 hole injection dopant, 17 hole transport dopant, 18 electron Implanted dopant, 19 Electron transport dopant

Claims (7)

An organic electroluminescence device in which at least an organic thin film is formed between an anode and a cathode,
The organic thin film is configured by doping a plurality of different dopants with a distribution in the film thickness direction with respect to a single host material layer.   One of the dopants is a dopant that imparts light emission characteristics, and the other dopant imparts any of hole injection characteristics and / or hole transport characteristics, electron injection characteristics, and / or electron transport characteristics. The organic electroluminescence device according to claim 1, wherein the organic electroluminescence device is a dopant.   In the film thickness direction of the host material layer, a hole dopant region in which a dopant imparting hole injection properties and / or hole transport properties is implanted, a light emitting region doped with a dopant imparting light emission properties, and electron injection 3. The organic electroluminescence device according to claim 2, wherein an electron dopant region doped with a dopant imparting characteristics and / or electron transport characteristics is formed sequentially.   The organic electroluminescence device according to claim 3, wherein the light emitting region and at least one of the hole dopant region and the electron dopant region partially overlap in the film thickness direction.   The light emitting region doped with the dopant that imparts the light emission characteristics is doped with a dopant that imparts red light emission characteristics, a dopant that imparts green light emission characteristics, and a dopant that imparts blue light emission characteristics. The organic electroluminescence element according to claim 2, wherein the organic electroluminescence element is characterized in that   The light emitting region doped with the dopant imparting the light emission characteristics includes a region doped with a dopant imparting red light emission characteristics, a region doped with a dopant imparting green light emission characteristics, and a dopant imparting blue light emission characteristics. The organic electroluminescence device according to any one of claims 2 to 4, wherein the organic electroluminescence device has a doped region in a film thickness direction.   The region doped with the dopant imparting the electron injection property and / or the electron transport property includes an organic dopant region doped with an organic dopant and a metal dopant region doped with a metal dopant in the film thickness direction. 5. The organic dopant region is disposed between a light emitting region doped with a dopant that imparts the light emission characteristics and the metal dopant region. 6. The organic electroluminescence element according to item.

Images