JP5656765B2 - ORGANIC LIGHT EMITTING ELEMENT, LIGHT SOURCE DEVICE USING ORGANIC LIGHT EMITTING ELEMENT AND METHOD FOR PRODUCING THEM - Google Patents

Description

  The present invention relates to an organic light-emitting element, a light source device using the organic light-emitting element, and a method for manufacturing the same.

  Organic having at least three organic layers between a cathode and an anode in order to provide an organic EL element, an illuminating device and a display device having high external extraction quantum efficiency, long emission lifetime, and low driving voltage In the electroluminescence element, at least two layers A and B of the organic layer are each formed by a coating method using a non-aqueous solvent, and a mixed region is formed between the layer A and the layer B, and Patent Document 1 reports an organic electroluminescence device characterized in that the concentration distribution of the constituent components of the layer A or the layer B in the mixed region shows a continuous concentration gradient.

In Non-Patent Document 1, the layer A is formed by a coating method using an organic solvent, and the layer B is formed thereon by a coating method using an alcohol solvent, and mixed between the layer A and the layer B. An organic electroluminescence device characterized in that no region is formed has been reported.
The following patent documents 2 to 3 exist as other prior art documents related to the present invention.

JP 2007-42314 A JP 2009-267392 A WO 2006-103909

Organic Electronics, V. 12, p. 291 (2011)

  In order to improve the light emission efficiency of the organic light emitting device, it is necessary to efficiently generate an excited state by confining both carriers of electrons and holes in the light emitting layer. Therefore, it is necessary to adjoin a light-emitting layer with a carrier transport layer made of a carrier transport material that confines carriers that try to penetrate the light-emitting layer in the light-emitting layer. Moreover, in order to obtain white light, a plurality of light-emitting dopants are necessary. However, when a plurality of dopants are dispersed in one light-emitting layer, a long-wavelength light-emitting dopant shines strongly, and desired white light is emitted. There is a problem that cannot be obtained. For this problem, a plurality of light emitting layers in which one or two light emitting dopants are dispersed are effective. For the above reasons, it is effective to adopt a multilayer structure. However, in the coating method, there is a problem that the base layer is dissolved by the solvent of the upper organic layer when it is multi-layered, and conventionally, an organic light emitting device having an organic multilayer structure of four or more layers could not be manufactured.

  An object of the present invention is to provide an organic light-emitting element having a multilayer structure, a light source device using the organic light-emitting element, and a method for manufacturing the same.

  The organic light emitting device of the present invention includes a lower electrode, an upper electrode, a light emitting layer and a mixed layer disposed between the lower electrode and the upper electrode, and the mixed layer includes a first host. A first dopant and a charge transporting material, the light emitting layer includes a second host, the charge transporting material includes a first functional group, and the charge transporting material includes: The concentration is higher in the region of the mixed layer where the light emitting layer is not present than in the region of the mixed layer where the light emitting layer is present.

  According to the present invention, it is possible to provide an organic light-emitting device having a multilayer structure, a light source device using the organic light-emitting device, and a manufacturing method thereof. Since the first mixed layer can be pseudo-separated into a light emitting layer and a charge transport layer by using a multilayer structure, a highly efficient organic light emitting device can be realized.

It is sectional drawing in one Embodiment of a light source device. It is sectional drawing in one Embodiment of an organic light emitting element. It is sectional drawing in one Embodiment of an organic light emitting element. It is sectional drawing in one Embodiment of an organic light emitting element. It is sectional drawing in one Embodiment of an organic light emitting element. It is the layer structure 1 before and after a pseudo | simulated laminated structure is formed. It is the layer structure 2 before and after a pseudo | simulated laminated structure is formed. It is the layer structure 3 before and after a pseudo | simulated laminated structure is formed. It is the layer structure 4 before and after a pseudo | simulated laminated structure is formed. It is the layer structure 5 before and after a pseudo | simulated laminated structure is formed. It is the layer structure 6 before and after a pseudo | simulated laminated structure is formed. It is the layer structure 7 before and after a pseudo | simulated laminated structure is formed. It is the layer structure 8 before and after a pseudo | simulated laminated structure is formed. It is a block diagram of the light source device of this invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various modifications by those skilled in the art are within the scope of the technical idea disclosed in this specification. Changes and modifications are possible. In all the drawings for explaining the present invention, components having the same function are denoted by the same reference numerals, and repeated description thereof may be omitted. FIG. 1 is a cross-sectional view of an embodiment of a light source device according to the present invention. FIG. 1 shows a top emission type light source device that extracts light from the upper electrode 102 side. In FIG. 1, the lower electrode 101, the first bank 104, the second bank 105, the organic layer 103, the upper electrode 102, the resin layer 106, the sealing substrate 107, and the light extraction layer 108 are arranged on the substrate 100 in the above order. Has been placed. A light source device is provided by including a drive circuit and a housing not shown in FIG. The organic light emitting device has an upper electrode 102, a lower electrode 101, and an organic layer 103.

  The lower electrode 101 is an anode. The lower electrode 101 may be a cathode. The lower electrode 101 is formed by patterning by photolithography.

When the lower electrode 101 is an anode, the upper electrode 102 is a cathode. When the lower electrode 101 is a cathode, the upper electrode 102 is an anode. When the upper electrode 102 is ITO or IZO, when ITO or IZO is formed by sputtering, a buffer layer may be provided between the organic layer 103 and the upper electrode 102 in order to reduce damage caused by sputtering. For the buffer layer, a metal oxide such as molybdenum oxide or vanadium oxide, or an extremely thin film of MgAg alloy is used. The upper electrode 102 is connected to the lower electrode 101 of the adjacent light emitting unit.
Thereby, a light emission part can be connected in series.

  The first bank 104 formed on the side surface of the organic light emitting device has a forward taper, covers the end of the patterned lower electrode 101, and prevents a partial short-circuit failure of the light emitting unit. After the organic layer 103 is formed by coating, the first bank 104 is formed by developing and exposing using a predetermined photomask. The surface of the first bank 104 on the side where the organic layer 103 is present may be subjected to water repellency treatment. For example, the surface of the first bank 104 is subjected to a plasma treatment with a fluorine-based gas, and the surface of the first bank 104 is fluorinated to perform the water repellency treatment. Thereby, a water repellent layer is formed on the surface of the first bank 104. Photosensitive polyimide is preferable as the first bank 104. As the first bank 104, an acrylic resin, a novolac resin, a phenol resin, a non-photosensitive material, or the like can be used.

  The second bank 105 is formed on the first bank 104. The second bank 105 has a reverse taper and is used to prevent the upper electrode 102 of the adjacent light emitting portion from conducting. After the organic layer 103 is formed by coating, the second bank 105 is formed by developing and exposing using a predetermined photomask. The surface of the second bank 105 on the side where the organic layer 103 is present may be subjected to water repellency treatment. For example, the surface of the second bank 105 is subjected to a plasma treatment with a fluorine-based gas, and the surface of the second bank 105 is fluorinated to perform the water repellency treatment. Thereby, a water repellent layer is formed on the surface of the second bank 105. It is preferable to use a negative photoresist as the second bank 105. As the second bank 105, an acrylic resin, a polyimide resin, a novolac resin, a phenol resin, a non-photosensitive material, or the like can be used.

  The resin layer 106 is formed on the upper electrode 102 and the second bank 105. The resin layer 106 is used in order to seal the light emitting portion and prevent intrusion of gas and moisture that cause deterioration of the light emitting element. As the resin layer 106, various polymers such as an epoxy resin can be used. In order to improve the sealing performance, an inorganic passivation film on the upper electrode 102 can be used as the resin layer 106.

  The sealing substrate 107 is formed on the resin layer 106. The sealing substrate 107 is a glass substrate. However, other than the glass substrate, a plastic substrate having an appropriate gas barrier film can also be used.

  The light extraction layer 108 is formed on the sealing substrate 107. The light extraction layer 108 is used for efficiently extracting light emitted from the organic layer 103. As the light extraction layer 108, for example, a structure such as a microlens, or a film having scattering properties and diffuse reflection properties is used.

  The organic light emitting element used here may be a single element or an element divided into a plurality of elements. Examples of a method of connecting a plurality of elements include a method in which each element is connected in series, in parallel, or a combination thereof.

  FIG. 2 is a cross-sectional view of an organic light emitting device according to an embodiment of the present invention. The substrate 100, the lower electrode 101, the organic layer 103, and the upper electrode 102 are arranged in this order from the lower side of FIG. 2, and the organic light emitting device of FIG. 2 is a top emission type that extracts light emitted from the organic layer 103 from the upper electrode 102 side. is there. The lower electrode 101 is a reflective electrode serving as a cathode, and the upper electrode 102 is a transparent electrode serving as an anode. As long as the upper electrode 102 is a cathode and the lower electrode 101 is an anode, a bottom emission type element structure in which the upper electrode 102 is a reflective electrode and the lower electrode 101 is a transparent electrode may be used. The substrate 100 and the lower electrode 101, the lower electrode 101 and the organic layer 103, the organic layer 103 and the upper electrode 102 may be in contact with each other, and an inorganic buffer layer or an injection layer may be interposed between the layers. Examples of the inorganic buffer layer include vanadium oxide, molybdenum oxide, tungsten oxide, and the like. Examples of the injection layer include an electron injection layer and a hole injection layer.

  The organic layer 103 includes a charge transport layer 10, a light emitting layer 11, and a mixed layer 12. In FIG. 2, the thickness of the mixed layer 12 is larger than the thickness of the charge transport layer 10 and the light emitting layer 11, but the thickness of the mixed layer 12 is made equal to the thickness of the charge transport layer 10 or the light emitting layer 11. Alternatively, the thickness of the mixed layer 12 may be smaller than the thickness of the charge transport layer 10 or the light emitting layer 11. In FIG. 2, the lower electrode 101 is formed on the substrate 100, the charge transport layer 10 is formed on the lower electrode 101, the light emitting layer 11 is formed on the charge transport layer 10, and the light emitting layer 11 is formed. A mixed layer 12 is formed, and an upper electrode 102 is formed on the mixed layer 12. As shown in FIG. 3, the charge transport layer 10 is formed on the lower electrode 101, the mixed layer 12 is formed on the charge transport layer 10, the light emitting layer 11 is formed on the mixed layer 12, and the light emitting layer 11 is formed. An upper electrode 102 may be formed thereon.

  Examples of the charge transport layer 10 include an electron transport layer and a hole transport layer.

  The light emitting layer 11 contains a host, a second dopant, and a third dopant. In the light emitting layer 11, electrons and holes are recombined by the host, the second dopant, or the third dopant, and the light emitting layer 11 emits light. The portion that emits light may be in the layer of the light emitting layer 11 or may be an interface between the light emitting layer 11 and an adjacent layer.

  The mixed layer 12 includes a host, a first dopant, and a charge transport material. The mixed layer 12 may contain an electron donating material or an electron accepting material. In the mixed layer 12, electrons and holes are recombined by the host or the first dopant, and the mixed layer 12 emits light. The portion that emits light may be in the layer of the mixed layer 12 or an interface between the mixed layer 12 and a layer adjacent to the mixed layer 12.

  As the organic layer 103, layers other than the charge transport layer 10, the light emitting layer 11, and the mixed layer 12 may be included. Examples of the layer other than the charge transport layer 10, the light emitting layer 11, and the mixed layer 12 include one or more of an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer. The charge transport layer 10, the light emitting layer 11, and the mixed layer 12 may be in contact with each other, and an inorganic buffer layer, an injection layer, or the like may be interposed between the charge transport layer 10, the light emitting layer 11, and the mixed layer 12. Good.

  Examples of the first dopant, the second dopant, and the third dopant include a fluorescent compound and a phosphorescent compound. Moreover, a red dopant, a green dopant, a blue dopant, etc. are mentioned as a 1st dopant, a 2nd dopant, and a 3rd dopant.

  The manufacturing method of the organic light emitting device is roughly classified into a vacuum deposition method and a coating method. Among them, the coating method has advantages such as easy formation of a large area and high material utilization efficiency. In order to use the coating method, it is necessary to reduce the number of layers of the organic light emitting element, and it is required to make the light emitting layer a single layer or two layers.

  In an organic light emitting device manufactured by a conventional coating method, a mixed layer is formed by controlling a lower layer region to be redissolved when multiple layers are stacked by utilizing a difference in solubility of each material in a solvent. In this method, it is difficult to control the concentration of the material contained in the mixed layer.

  The charge transport material contains a first functional group. By the first functional group, the charge transport material is attracted to the opposite surface of the mixed layer 12 where the light emitting layer 11 is present.

The host contains a second functional group, and the first dopant contains a third functional group. In that case, the host and the first dopant are attracted to the surface of the mixed layer 12 on the side where the light emitting layer 11 exists by the second functional group and the third functional group. The host may not contain the first functional group. Further, the first dopant may not contain the third functional group. When the second functional group is contained in the host or the third functional group is contained in the first dopant, the concentration control of the first dopant becomes easy.
Hereinafter, the case where the host contains the second functional group and the first dopant contains the third functional group will be described in detail.

  It is desirable that the host of the light emitting layer 11 contains a fourth functional group. In that case, the interaction with the second functional group of the host of the mixed layer 12 and the third functional group of the first dopant becomes strong. Moreover, it is desirable that the emission color of the second dopant and the third dopant of the light emitting layer is different from the emission color of the first dopant. “Different emission colors” means that the wavelengths indicating the maximum intensities in the PL spectra of the respective dopants are different. One of the emission colors of the second dopant and the third dopant in the light emitting layer 11 is preferably red, and the other is preferably green. Thereby, the influence of the energy transfer from the second dopant to the third dopant or from the third dopant to the second dopant can be minimized. White light is emitted from the organic light emitting device by adjusting the maximum intensity of the PL spectrum of the first dopant and the second dopant.

  In the present invention, the mixed layer is a layer (charge transport material, host, dopant, etc.) contained in the layer moves in a predetermined film thickness direction in the layer by the function of the functional group. On the other hand, the light emitting layer is a layer in which the substances (host, dopant, etc.) contained in the layer are dispersed in principle.

  As shown in FIG. 2, when the charge transport layer 10, the light emitting layer 11, the mixed layer 12, and the upper electrode 102 are formed in this order, examples of the first functional group include a fluoroalkyl group, a perfluoroalkyl group, and an alkyl group. And a group (provided that the number of C is 10 or more), a perfluoropolyether group, and a siloxy group (—Si—O—Si—). Considering the surface energy, a fluoroalkyl group and a perfluoropolyether group are desirable, and a perfluoroalkyl group is more desirable. The host and the first dopant may have at least one of these functional groups, but they may have a plurality of types. These groups may be introduced directly into the main skeleton, but may be introduced via an amide bond or an ester bond as in (Chemical Formula 1).

  Unlike the inside (bulk), the surface of a substance is generally unstable because of the absence of the same kind of molecules on one side and no attractive force. Therefore, a force (surface tension) for deforming the surface area to reduce the surface energy acts. In addition, when there is a molecule having a functional group with low surface energy in the substance, the surface energy is lowered and stabilized by exposing the functional group to the surface. For example, in the case of water and a surfactant (amphiphilic molecule), the surfactant has a hydrophobic group, which is a functional group having a low surface energy, in the molecule, and the single molecule on the surface of the water in the form of releasing the hydrophobic group from the water surface. The surface energy of the water surface is reduced by forming a film.

  The molecule of the present invention has a functional group having a low surface energy such as a fluoroalkyl group in the molecule. Sites such as the benzene ring have higher surface energy. When a film is formed, a force acts to bring out the functional group having a low surface energy on the surface in order to reduce the surface energy. In a molecule to which a functional group is added as in (Chemical Formula 1), a functional group having a low surface energy can be moved to the film surface by this action.

  In the case of utilizing the interaction with the underlayer, the functional group is attracted to the underlayer by the action of intermolecular force, hydrogen bond, and coordination bond that acts between the underlayer and the functional group.

  By adding the first functional group to the charge transport material, the charge transport material is unevenly distributed and localized on the surface of the mixed layer 12 on the side where the upper electrode 102 exists. That is, the charge transport material forms a concentration gradient in the mixed layer 12. By adding the first functional group to the charge transport material, the position where the concentration of the charge transport material peaks in the film thickness direction of the mixed layer 12 exists on the upper electrode 102 side from the center of the mixed layer 12. It will be.

The second functional group, the third functional group, and the fourth functional group are classified as follows depending on the type of the host material of the light emitting layer. Examples of the material in which the host of the light emitting layer has a high hole transporting property include a phenylamino group, a carbazole group, and a hydrazone group. Examples of the material having a high electron transporting property as the host material of the light emitting layer include an oxadiazole group, a triazole group, and a phenanthroline group. When the host material of the light emitting layer is a material having a high hole transport property and electron transport property, a hydroxy group (—OH), a thiol group (—SH), a carboxyl group (—COOH), a sulfo group (—SO ₃ H), etc. Can be given. These groups may be introduced directly into the main skeleton as in (Chemical Formula 2), but introduced through an alkyl chain or the like in consideration of the amide bond, ester bond, or molecular size as in (Chemical Formula 3). It doesn't matter. Further, the host and the first dopant may have at least one of these functional groups, but may have a plurality of types.

  As shown in FIG. 3, when the charge transport layer 10, the mixed layer 12, the light emitting layer 11, and the upper electrode 102 are formed in this order, the first functional group depends on the type of the charge transport layer 10 in contact with the mixed layer 12. It is divided as follows.

  When the charge transport layer 10 is a hole transport layer, the same structure as the hole transport layer is introduced into the first functional group. Specific examples include a phenylamino group, a carbazole group, and a hydrazone site.

  When the charge transport layer 10 is an electron transport layer, a structure similar to that of the electron transport layer is introduced into the first functional group. Specific examples include an oxadiazole group, a triazole group, a phenanthroline site, and the like.

  Examples of the second functional group and the third functional group include a fluoroalkyl group, a perfluoroalkyl group, an alkyl group (however, the number of C is 10 or more), a perfluoropolyether group, and a siloxy group. (-Si-O-Si-). Considering the surface energy, a fluoroalkyl group and a perfluoropolyether group are desirable, and a perfluoroalkyl group is more desirable. The host and the first dopant may have at least one of these functional groups, but they may have a plurality of types. These groups may be directly introduced into the main skeleton, but may be introduced via an amide bond or an ester bond as in (Chemical Formula 1).

  As the charge transport material, a hole transport material or an electron transport material can be considered. Examples of the hole transporting material include starburst amine compounds, stilbene derivatives, hydrazone derivatives, thiophene derivatives, and fluorene derivatives. Examples of the electron transporting material include bis (2-methyl-8-quinolinolato) -4- (phenylphenolato) aluminum (BAlq), tris (8-quinolinolato) aluminum (Alq3), Tris (2, 4, 6- trimethyl-3- (pyridin-3-yl) phenyl) borane (3TPYMB), 1,4-Bis (triphenylsilyl) benzene (UGH2), oxadiazole derivatives, triazole derivatives, fullerene derivatives, phenanthroline derivatives, quinoline derivatives, silole derivatives Etc.

When a hole transporting material is used as the charge transporting material, an electron accepting material may be added to the mixed layer 12 in order to reduce the resistance of the mixed layer 12 and reduce the driving voltage. The electron-accepting material refers to a material that easily receives electrons from molecules other than the electron-accepting material. Examples of the electron-accepting material include 7, 7, 8, 8-tetracyanoquinodimethane (TCNQ) derivatives. The electron-accepting material in the mixed layer 12 may contain a second functional group.
By including the second functional group in the electron-accepting material, the electron-accepting material in the light-emitting layer region is reduced, and the light emission efficiency can be improved.

  When an electron transporting material is used as the charge transporting material, an electron donating material may be added to the mixed layer 12 in order to reduce the resistance of the mixed layer 12 and reduce the driving voltage of the element. The electron-accepting material refers to a material that easily emits electrons (easy to pass to molecules other than the electron-accepting material). Examples of electron donating materials include N-ethyl-1, 10-phenanthrolium (NEP) derivatives, Methyltriphenylphosphonium (MTPP) derivatives, N, N, N, N-tetramethyl-p-phenylenendiamine (TMPD) derivatives, rhodamine B chloride derivatives. , Pyroin B chloride derivatives, 8-hydroxyquinolinolato-lithium (Liq) derivatives, and the like. The electron-donating material in the mixed layer 12 may contain a second functional group. By including the second functional group in the electron donating material, the electron donating material in the light emitting layer region is reduced, and the light emission efficiency can be improved.

<Layer structure 1>
As the layer configuration 1, consider the case of lower electrode 101 / hole transport layer (charge transport layer 10) / light emitting layer 11 (light emitting layer) / mixed layer 12 (light emitting layer + electron transport layer) / upper electrode 102. Layer structure 1 corresponds to FIG.

The light emitting layer 11 includes a second host, a second dopant, and a third dopant.
The mixed layer 12 includes a first host, a first dopant, and an electron transporting material. In this case, the lower electrode 101 is an anode and the upper electrode 102 is a cathode (top cathode). The hole transport layer is preferably insolubilized with respect to the mixed layer forming solvent in order to prevent re-dissolution when the light emitting layer 11 is applied. Examples of the hole transport layer insolubilized in the mixed layer forming solvent include materials having the structures (1.a) to (6.a) described in JP-A-2009-267392. .

  FIG. 6 shows the layer structure 1 before and after the pseudo laminated structure is formed. The first functional group to be added to the electron transport material of the mixed layer 12 moves the electron transport material to the side where the upper electrode 102 exists, the second functional group to be added to the first host, and the first functional group. The third functional group added to one dopant moves the first host and the first dopant to the side where the lower electrode 101 exists, thereby forming a pseudo stacked structure (light emitting layer / electron transport layer). ).

  With the above configuration, the light emitting layer containing the second dopant and the third dopant and the light emitting layer containing the first dopant are pseudo-clipped between the hole transport layer and the electron transport layer by a coating method. An organic layer having a four-layer structure is obtained. With this structure, the first to third dopants can emit light efficiently, and a high-efficiency organic light-emitting device can be produced.

  Here, the movement of the first dopant means that the ratio of the first dopant existing at the destination increases and the concentration thereof increases. This is the same when other dopants or hosts move. The same applies to other layer configurations.

<Layer structure 2>
As layer structure 2, consider the case of lower electrode 101 / electron transport layer (charge transport layer 10) / light emitting layer 11 (light emitting layer) / mixed layer 12 (light emitting layer + hole transport layer) / upper electrode 102. Layer structure 2 corresponds to FIG. The light emitting layer 11 includes a second host, a second dopant, and a third dopant. The mixed layer 12 includes a first host, a first dopant, and a hole transporting material. In this case, the lower electrode 101 is a cathode, and the upper electrode 102 is an anode (top anode). The electron transport layer is preferably insolubilized in the mixed layer forming solvent in order to prevent re-dissolution when the light emitting layer 11 is applied. Examples of the electron transport layer insolubilized in the mixed layer forming solvent include materials described in JP-A-2006-279007.

  FIG. 7 shows the layer structure 2 before and after the pseudo laminated structure is formed. The first functional group added to the hole transport material of the mixed layer 12 moves the hole transport material to the side where the upper electrode 102 exists, and the second functional group added to the first host, And the third functional group added to the first dopant moves the first host and the first dopant to the side where the lower electrode 101 exists, thereby forming a pseudo stacked structure (light emitting layer / positive layer). Hole transport layer).

  With the above configuration, a pseudo-light emitting layer containing the second dopant and the third dopant and the light emitting layer containing the first dopant are sandwiched between the electron transport layer and the hole transport layer by a coating method. An organic layer having a four-layer structure is obtained. With this structure, the first to third dopants can emit light efficiently, and a high-efficiency organic light-emitting device can be produced.

<Layer structure 3>
As layer structure 3, consider the case of lower electrode 101 / hole transport layer (charge transport layer 10) / mixed layer 12 (hole transport layer + light emitting layer) / light emitting layer 11 (light emitting layer) / upper electrode 102. Layer structure 3 corresponds to FIG.

The light emitting layer 11 includes a second host, a second dopant, and a third dopant.
The mixed layer 12 includes a first host, a first dopant, and a hole transporting material. The lower electrode 101 serves as an anode, and the upper electrode 102 serves as a cathode (top cathode). The hole transport layer is preferably the same as the material of the layer structure 1.

  FIG. 8 shows the layer structure 3 before and after the pseudo laminated structure is formed. The second functional group added to the first host and the third functional group added to the first dopant move the first host and the first dopant to the side where the upper electrode 102 exists. In addition, the first functional group added to the hole transporting material moves the hole transporting material to the side where the lower electrode 101 exists, so that a pseudo laminated structure (hole transporting layer / Light emitting layer).

  With the above configuration, a high-efficiency organic light-emitting element having a pseudo four-layered organic layer including the mixed layer 12 by a coating method can be produced.

  In this configuration, the hole transport material of the mixed layer is made of a material having a high triplet energy state that does not deactivate the excited state of the first dopant, or low enough to block electrons penetrating the light emitting layer of the mixed layer. High efficiency light emission can be obtained by using an electron affinity material.

<Layer structure 4>
As the layer structure 4, consider the case of lower electrode 101 / electron transport layer (charge transport layer 10) / mixed layer 12 (electron transport layer + light emitting layer) / light emitting layer 11 (light emitting layer) / upper electrode 102. Layer structure 4 corresponds to FIG.

The light emitting layer 11 includes a second host, a second dopant, and a third dopant.
The mixed layer 12 includes a first host, a first dopant, and an electron transporting material. In this case, the lower electrode 101 is a cathode, and the upper electrode 102 is an anode (top anode). The electron transport layer is preferably the same as the material of the layer structure 2.

  FIG. 9 shows the layer structure 4 before and after the pseudo laminated structure is formed. The first functional group added to the electron transporting material moves the electron transporting material to the side where the lower electrode 101 exists, and is added to the second functional group added to the host and the first dopant. The third functional group to move forms the pseudo laminated structure (electron transport layer / light emitting layer) by moving the host and the first dopant to the side where the upper electrode 102 exists.

  With the above configuration, a high-efficiency organic light-emitting element having a pseudo four-layered organic layer including the mixed layer 12 by a coating method can be produced.

  In this configuration, the electron transport material of the mixed layer is used as a material having a high triplet energy state that does not deactivate the excited state of the first dopant, or a high ionization potential that blocks holes penetrating the light emitting layer of the mixed layer. By using this material, high-efficiency light emission can be obtained.

<Layer structure 5>
As the layer structure 5, consider the case of lower electrode 101 / hole transport layer (charge transport layer 10) / second mixed layer 13 / first mixed layer 12 / upper electrode 102. Layer structure 5 corresponds to FIG.
The first mixed layer 12 includes a first host, a first dopant, and an electron transport material.
The second mixed layer contains a second host, a second dopant, and a third dopant. In this case, the lower electrode 101 is an anode and the upper electrode 102 is a cathode (top cathode).

  FIG. 10 shows the layer structure 5 before and after the pseudo laminated structure is formed. The hole transport material used for the hole transport layer has a phenylamino group, a carbazole group, a hydrazone site, and the like. Therefore, the second dopant moves to the charge transport layer 10 side due to the sixth functional group similar to the above-mentioned site added to the second dopant. Further, the third dopant moves to the first mixed layer 12 side by the added seventh functional group. Therefore, the second mixed layer 13 functions as a light emitting layer having a pseudo two-layer structure. In the present configuration, a third host may be included in the second mixed layer. The third host moves to the first mixed layer 12 side by the added eighth functional group and functions as the main host of the third dopant.

Next, the second host is a phenylamino group, carbazole group, hydrazone group, oxadiazole group, triazole group, phenanthroline group, hydroxy group (—OH), thiol group (—SH), carboxyl group (—COOH). , A sulfo group (—SO ₃ H) and the like are added, and by adding a second functional group and a third functional group similar to the first host and the first dopant, the first functional group is added. The host and the first dopant move to the second mixed layer 13 side. Further, the electron transporting material moves to the upper electrode 102 side by the added first functional group. Therefore, the first mixed layer 12 functions as a pseudo laminated structure including a light emitting layer and an electron transport layer. As described above, the light emitting layer containing the second dopant, the light emitting layer containing the third dopant, and the light emitting layer containing the first dopant were sandwiched between the hole transport layer and the electron transport layer by the coating method. An organic layer having a pseudo five-layer structure is obtained. Since the first to third dopants are particularly separated from the second dopant and the third dopant, the first to third dopants can emit light more efficiently and become a high-efficiency organic light-emitting device.

<Layer structure 6>
As the layer structure 6, consider the case of lower electrode 101 / electron transport layer (charge transport layer 10) / second mixed layer 13 / first mixed layer 12 / upper electrode 102. The layer structure 6 corresponds to FIG.
The first mixed layer 12 includes a first host, a first dopant, and a hole transport material.
The second mixed layer contains a second host, a second dopant, and a third dopant. In this case, the lower electrode 101 is a cathode, and the upper electrode 102 is an anode (top anode).

  FIG. 11 shows the layer structure 6 before and after the pseudo laminated structure is formed. The electron transport material used for the electron transport layer has an oxadiazole group, a triazole group, a phenanthroline site, and the like. Therefore, the second dopant moves to the charge transport layer 10 side due to the sixth functional group similar to the above-mentioned site added to the second dopant. Further, the third dopant moves to the first mixed layer 12 side by the added seventh functional group. Therefore, the second mixed layer 13 functions as a light emitting layer having a pseudo two-layer structure. In the present configuration, a third host may be included in the second mixed layer. The third host moves to the first mixed layer 12 side by the added eighth functional group and functions as the main host of the third dopant.

Next, the second host is a phenylamino group, carbazole group, hydrazone group, oxadiazole group, triazole group, phenanthroline group, hydroxy group (—OH), thiol group (—SH), carboxyl group (—COOH). , A sulfo group (—SO ₃ H) and the like are added, and by adding a second functional group and a third functional group similar to the first host and the first dopant, the first functional group is added. The host and the first dopant move to the second mixed layer 13 side. The hole transporting material moves to the upper electrode 102 side by the added first functional group. Therefore, the first mixed layer 12 functions as a pseudo stacked structure including a light emitting layer and a hole transport layer. As described above, the light-emitting layer containing the second dopant, the light-emitting layer containing the third dopant, and the light-emitting layer containing the first dopant were sandwiched between the electron transport layer and the hole transport layer by the coating method. A pseudo five-layer laminated structure is obtained. Since the first to third dopants are particularly separated from the second dopant and the third dopant, the first to third dopants can emit light more efficiently and become a high-efficiency organic light-emitting device.

<Layer structure 7>
As the layer structure 7, consider the case of lower electrode 101 / hole transport layer (charge transport layer 10) / first mixed layer 12 / second mixed layer 13 / upper electrode 102. The layer structure 7 corresponds to FIG.
The first mixed layer includes a first host, a first dopant, and a hole transport material. The second mixed layer contains a second host, a second dopant, and a third dopant.
In this case, the lower electrode 101 is an anode and the upper electrode 102 is a cathode (top cathode).

  FIG. 12 shows the layer structure 7 before and after the pseudo laminated structure is formed.

  The hole transport material used for the hole transport layer has a phenylamino group, a carbazole group, a hydrazone site, and the like. Therefore, the hole transport material contained in the first mixed layer moves to the charge transport layer 10 side due to the above-described site or a similar first functional group. Further, the first dopant moves to the second mixed layer 13 side by the added third functional group. Therefore, the first mixed layer 12 functions as a pseudo stacked structure including a light emitting layer and a hole transport layer.

Next, the first host is phenylamino group, carbazole group, hydrazone group, oxadiazole group, triazole group, phenanthroline group, hydroxy group (—OH), thiol group (—SH), carboxyl group (—COOH). , A sulfo group (—SO ₃ H) and the like are added, and the second host, the fifth functional group similar to the third dopant, and the seventh functional group are added, whereby the second The host and the third dopant move to the first mixed layer 12 side. Further, the second dopant moves to the upper electrode 102 side by the added sixth functional group.
Therefore, the second mixed layer 13 functions as a pseudo two-layer structure including two light emitting layers. In the present configuration, a third host may be included in the second mixed layer. The third host moves to the upper electrode 102 side by the added eighth functional group and functions as the main host of the third dopant.

  As described above, a pseudo hole transport layer, a light emitting layer containing a first dopant, a light emitting layer containing a second dopant, and a light emitting layer containing a third dopant are formed by a coating method. An organic layer having a five-layer structure is obtained. In this configuration, the hole transport material of the first mixed layer is used as a material having a high triplet energy state that does not deactivate the excited state of the first dopant, or blocks electrons penetrating the light emitting layer of the first mixed layer. By using such a low electron affinity material, high-efficiency light emission can be obtained.

<Layer structure 8>
As the layer structure 8, consider the case of lower electrode 101 / electron transport layer (charge transport layer 10) / first mixed layer 12 / second mixed layer 13 / upper electrode 102. The layer structure 8 corresponds to FIG.
The first mixed layer 12 includes a first host, a first dopant, and an electron transport material.
The second mixed layer contains a second host, a second dopant, and a third dopant. In this case, the lower electrode 101 is an anode and the upper electrode 102 is a cathode (top cathode).

  FIG. 13 shows the layer structure 8 before and after the pseudo laminated structure is formed.

The electron transport material used for the electron transport layer has an oxadiazole group, a triazole group, a phenanthroline site, and the like. Therefore, the electron transport material contained in the first mixed layer moves to the charge transport layer 10 side due to the above-described site or a similar first functional group.
Further, the first dopant moves to the second mixed layer 13 side by the added third functional group. Therefore, the first mixed layer 12 functions as a pseudo laminated structure including a light emitting layer and an electron transport layer.

Next, the first host is phenylamino group, carbazole group, hydrazone group, oxadiazole group, triazole group, phenanthroline group, hydroxy group (—OH), thiol group (—SH), carboxyl group (—COOH). , A sulfo group (—SO ₃ H) and the like are added, and the second host, the fifth functional group similar to the third dopant, and the seventh functional group are added, whereby the second The host and the third dopant move to the first mixed layer 12 side. Further, the second dopant moves to the upper electrode 102 side by the added sixth functional group.
Therefore, the second mixed layer 13 functions as a pseudo two-layer structure including two light emitting layers. In the present configuration, a third host may be included in the second mixed layer. The third host moves to the upper electrode 102 side by the added eighth functional group and functions as the main host of the third dopant.

  As described above, a pseudo 5 consisting of an electron transport layer, a light emitting layer containing a first dopant, a light emitting layer containing a second dopant, and a light emitting layer containing a third dopant by a coating method. An organic layer having a layered structure is obtained. In this configuration, the electron transport material of the first mixed layer is used as a material having a high triplet energy state that does not deactivate the excited state of the first dopant, or holes that penetrate the light emitting layer of the first mixed layer are blocked. By using such a material with a high ionization potential, high-efficiency light emission can be obtained. A high-efficiency organic light-emitting device having a pseudo five-layer organic layer including two mixed layers (first mixed layer 12 and second mixed layer 13) can be manufactured.

<Host>
As the host, it is preferable to use a carbazole derivative, a fluorene derivative, an arylsilane derivative, or the like. In order to obtain efficient light emission, it is preferable that the excitation energy of the host is sufficiently larger than the excitation energy of the blue dopant. The excitation energy is measured using an emission spectrum.

<Blue dopant>
Blue dopants have a maximum PL spectrum intensity at room temperature between 400 nm and 500 nm. Examples of the main skeleton of the blue dopant include perylene and iridium complexes (Bis (3, 5-difluoro-2- (2-pyridyl) phenyl- (2-carboxypyridyl) iridium (III)): FIrpic and the like). Among them, the iridium complex represented by (Chemical Formula 11) is more preferable in terms of light emission characteristics. In the formula, X1 represents an aromatic heterocycle containing N, and X2 represents an aromatic hydrocarbon ring or an aromatic heterocycle.

  Examples of the aromatic heterocycle represented by X1 include quinoline ring, isoquinoline ring, pyridine ring, quinoxaline ring, thiazole ring, pyrimidine ring, benzothiazole ring, oxazole ring, benzoxazole ring, indole ring and isoindole ring. . Examples of the aromatic hydrocarbon ring or aromatic heterocycle represented by X2 include a benzene ring, naphthalene ring, anthracene ring, thiophene ring, benzothiophene ring, furan ring, benzofuran ring, and fluorene ring. In the formula, X3 includes acetylacetonate derivatives, picolinate derivatives, tetrakispyrazolyl borate derivatives and the like. X3 may be the same as X1-X2.

  From the viewpoint of luminous efficiency and carrier conduction, the concentration of the blue dopant in the mixed layer 12 is preferably 10 wt% or more with respect to the host. The weight average molecular weight of the blue dopant is preferably 500 or more and 3000 or less.

<Green dopant>
The green dopant has a maximum PL spectrum intensity at room temperature between 500 nm and 590 nm. Examples of the main skeleton of the green dopant include coumarin and derivatives thereof, and iridium complexes (Tris (2-phenylpyridine) iridium (III): hereinafter Ir (ppy) 3, etc.). Among them, the iridium complex represented by (Chemical Formula 11) is more preferable in terms of light emission characteristics. In the formula, X1 represents an aromatic heterocycle containing N, and X2 represents an aromatic hydrocarbon ring or an aromatic heterocycle.

  Examples of the aromatic heterocycle represented by X1 include quinoline ring, isoquinoline ring, pyridine ring, quinoxaline ring, thiazole ring, pyrimidine ring, benzothiazole ring, oxazole ring, benzoxazole ring, indole ring and isoindole ring. . Examples of the aromatic hydrocarbon ring or aromatic heterocycle represented by X2 include a benzene ring, naphthalene ring, anthracene ring, thiophene ring, benzothiophene ring, furan ring, benzofuran ring, and fluorene ring. X3 is an acetylacetonate derivative, and the same as X1-X2.

  From the viewpoint of luminous efficiency, suppression of energy transfer from the blue dopant, and carrier conduction, the concentration of the green dopant in the mixed layer 12 is preferably 1 wt% or less with respect to the host. The weight average molecular weight of the green dopant is preferably 500 or more and 3000 or less.

<Red dopant>
The red dopant has a maximum PL spectrum intensity at room temperature between 590 nm and 780 nm. Examples of the main skeleton of the red dopant include rubrene, (E) -2- (2- (4- (dimethylamino) styryl) -6-methyl-4H-pyran-4-ylidene) malononitrile (DCM) and its derivatives, iridium Complexes (Bis (1-phenylisoquinoline) (acetylacetonate) iridium (III) etc.), osmium complexes, and europium complexes can be mentioned. Among them, the iridium complex represented by (Chemical Formula 11) is more preferable in terms of light emission characteristics. In the formula, X1 represents an aromatic heterocycle containing N, and X2 represents an aromatic hydrocarbon ring or an aromatic heterocycle.

  Examples of the aromatic heterocycle represented by X1 include quinoline ring, isoquinoline ring, pyridine ring, quinoxaline ring, thiazole ring, pyrimidine ring, benzothiazole ring, oxazole ring, benzoxazole ring, indole ring and isoindole ring. . Examples of the aromatic hydrocarbon ring or aromatic heterocycle represented by X2 include a benzene ring, naphthalene ring, anthracene ring, thiophene ring, benzothiophene ring, furan ring, benzofuran ring, and fluorene ring. X3 is preferably an acetylacetonate derivative or the like.

  From the viewpoint of suppression of energy transfer from the blue dopant and carrier conduction, the concentration of the red dopant in the mixed layer 12 is preferably 1 wt% or less with respect to the host. The weight average molecular weight of the red dopant is preferably 500 or more and 3000 or less.

<Hole injection layer>
The hole injection layer is used for the purpose of improving luminous efficiency and lifetime. Moreover, although it is not essential, it is used for the purpose of relaxing the unevenness of the anode. A single hole injection layer or a plurality of hole injection layers may be provided. The hole injection layer is preferably a conductive polymer such as PEDOT (poly (3,4-ethylenedioxythiophene)): PSS (polystyrene sulfonate). In addition, polypyrrole-based or triphenylamine-based polymer materials can be used. Further, phthalocyanine compounds and starburst amine compounds that are often used in combination with a low molecular weight (weight average molecular weight 10,000 or less) material system are also applicable.

<Hole transport layer>
The hole transport layer is a layer that supplies holes to the light emitting layer. In a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. A single hole transport layer or a plurality of hole transport layers may be provided. As the hole transport layer, a starburst amine compound, a stilbene derivative, a hydrazone derivative, a thiophene derivative, a fluorene derivative, or the like can be used. Further, the present invention is not limited to these materials, and two or more of these materials may be used in combination. In order to lower the resistance of the hole transport layer and reduce the driving voltage, an electron accepting material may be added to the hole transport layer.

<Electron transport layer>
The electron transport layer is a layer that supplies electrons to the light emitting layer. In a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. A single layer or a plurality of electron transport layers may be provided. Examples of the material for the electron transport layer include bis (2-methyl-8-quinolinolato) -4- (phenylphenolato) aluminum (BAlq), tris (8-quinolinolato) aluminum (Alq3), Tris (2, 4,6-trimethyl-3- (pyridin-3-yl) phenyl) borane (3TPYMB), 1,4-Bis (triphenylsilyl) benzene (UGH2), oxadiazole derivative, triazole derivative, fullerene derivative, phenanthroline derivative, quinoline Derivatives, silole derivatives and the like can be used. In order to lower the resistance of the electron transport layer and reduce the driving voltage of the device, an electron donating material may be added to the electron transport layer.

<Electron injection layer>
The electron injection layer improves the electron injection efficiency from the cathode to the electron transport layer. Specifically, lithium fluoride, magnesium fluoride, calcium fluoride, strontium fluoride, barium fluoride, magnesium oxide, and aluminum oxide are desirable. Of course, the material is not limited to these materials, and two or more of these materials may be used in combination.

<Board>
Examples of the substrate 100 include a glass substrate, a metal substrate, a plastic substrate on which an inorganic material such as SiO ₂ , SiN _x , and Al ₂ O ₃ is formed. Examples of the metal substrate material include alloys such as stainless steel and 42 alloy. Examples of the plastic substrate material include polyethylene terephthalate, polyethylene naphthalate, polymethyl methacrylate, polysulfone, polycarbonate, and polyimide.

<Anode>
As the anode material, any material having a high work function can be used. Specifically, examples of materials that can be used as the transparent electrode include conductive oxides such as ITO and IZO, and metals having a high work function such as thin Ag. Moreover, as a reflective electrode, what laminated | stacked ITO on Al, ITO / Ag / ITO laminated film, Cr, Mo, etc. are mentioned. In the case of the lower electrode, the electrode pattern is generally formed by using photolithography on a substrate such as glass, and in the case of the upper electrode, it is performed by using a metal mask at the time of film formation. it can.

<Cathode>
The cathode material is preferably a metal having a small work function. Specifically, as a material used as the reflective electrode, a laminate of LiF and Al, an Mg: Ag alloy, or the like is preferably used. Examples of the transparent cathode include a thin Mg: Ag alloy, a thin Mg: Ag alloy laminated on ITO, and a laminate of LiF and IZO. Moreover, it is not limited to these materials, For example, a Cs compound, Ba compound, Ca compound etc. can be used instead of LiF. The patterning of the electrode can be performed in the same manner as the anode.

  Examples of the coating method for forming the light emitting layer 11 and the mixed layer 12 include spin coating, casting, dip coating, spray coating, screen printing, and inkjet printing. The light emitting layer 11 and the mixed layer 12 are formed using one of these methods.

  The present invention will be described in more detail with reference to specific examples.

  As a first example of the present invention, a white light emitting device having the structure shown in FIG. 2 was produced. An ITO electrode was used for the lower electrode 101, and a polymer material was used for the hole transport layer (charge transport layer 10). In the light emitting layer 11, (Chemical Formula 1) was used as a host, (Chemical Formula 2) was used as a green dopant, and (Chemical Formula 3) was used as a red dopant. The weight ratio of each material was 100: 10: 1.

  These hosts, green dopant material, and red dopant material were dissolved in toluene to prepare a coating solution. The solid component concentration of the coating liquid was set to 1 wt%. Using this coating solution, a light emitting layer was formed by spin coating.

  Next, in the mixed layer 12, (Chemical Formula 4) was used as the host, (Chemical Formula 5) was used as the blue dopant, and (Chemical Formula 6) was used as the electron transporting material.

  The weight ratio of each material was 100: 10: 100. These host, blue dopant material, and electron transport material were dissolved in 2-propanol to prepare a coating solution. The solid component concentration of the coating liquid was set to 1 wt%. Using this coating solution, a light emitting layer was formed by spin coating. Subsequently, a laminate of LiF and Al was formed as the upper electrode 102, and a target organic light emitting device was produced.

  In this organic light-emitting device, the electron transport material contained in the mixed layer is localized on the upper surface side by the substituent when the mixed film is formed, and a pseudo electron transport layer is formed. Therefore, in this organic light emitting element, a pseudo laminated structure of red green light emitting layer / blue light emitting layer / electron transport layer is formed. As a comparative example, an organic light emitting device was produced under the same conditions using a mixed layer forming coating solution not containing an electron transport material. When voltage was applied to the produced organic light emitting device, this example showed better light emission characteristics than the comparative example.

  As a second example of the present invention, a white light emitting device having the structure shown in FIG. 4 was produced. An ITO electrode was used for the lower electrode 101, and a polymer material was used for the hole transport layer (charge transport layer 10). In the first mixed layer 12, (Chemical formula 7) was used as the host, (Chemical formula 2) was used as the green dopant, and (Chemical formula 8) was used as the red dopant.

  The weight ratio of each material was 100: 10: 1. These hosts, green dopant material, and red dopant material were dissolved in toluene to prepare a coating solution. The solid component concentration of the coating liquid was set to 1 wt%. Using this coating solution, a light emitting layer was formed by spin coating.

  Next, (Chemical 9) was used as the host in the second mixed layer 13, (Chemical 10) was used as the blue dopant, and (Chemical 6) was used as the electron transporting material.

  The weight ratio of each material was 100: 10: 100. These host, blue dopant material, and electron transport material were dissolved in 2-propanol to prepare a coating solution. The solid component concentration of the coating liquid was set to 1 wt%. Using this coating solution, a light emitting layer was formed by spin coating. Subsequently, a laminate of LiF and Al was formed as the upper electrode 102, and a target organic light emitting device was produced.

  In the present organic light emitting layer device, the red dopant contained in the first mixed layer is localized on the upper surface of the film by a substituent during film formation. Therefore, the first mixed layer has a structure in which a green light emitting layer and a red light emitting layer are artificially stacked. Further, the electron transport material contained in the second mixed layer is localized on the upper surface side by the substituent when the mixed film is formed, and a pseudo electron transport layer is formed. Therefore, in this organic light emitting device, a pseudo laminated structure of green light emitting layer / red light emitting layer / blue light emitting layer / electron transport layer is formed. As a comparative example, an organic light emitting device was produced under the same conditions using a mixed layer forming coating solution not containing an electron transport material. When voltage was applied to the produced organic light emitting device, this example showed better light emission characteristics than the comparative example.

  As an example of the present invention, a light source device 506 shown in FIG. 14 was produced. The organic light-emitting element, which is a component of the light source device 506, includes the same substrate 100, lower electrode 101, organic layer 103, and upper electrode 102 as in the first embodiment. The organic light emitting element is sealed with a sealing tube glass 501 with a desiccant so that the organic layer 103 is shielded from the outside air. The lower electrode 101 and the upper electrode 102 are connected to the drive circuit 503 through the wiring 502, respectively. Then, the organic light emitting element with the sealing tube glass 501 and the drive circuit 503 are covered with a housing 505 to form the light source device 506 as a whole. Note that the drive circuit 503 is lit by being connected to an external power source through the plug 504.

10 charge transport layer 11 light emitting layer 12 first mixed layer (mixed layer)
13 Second mixed layer 100 Substrate 101 Lower electrode 102 Upper electrode 103 Organic layer 104 First bank 105 Second bank 106 Resin layer 107 Sealing substrate 108 Light extraction layer 501 Sealing tube glass 502 Wiring 503 Drive circuit 504 Plug 505 Case 506 Light source device

Claims (18)

A lower electrode;
An upper electrode;
An organic light emitting device having a light emitting layer and a mixed layer disposed between the lower electrode and the upper electrode,
The mixed layer includes a first host, a first dopant, and a charge transport material,
The light emitting layer includes a second host,
The charge transport material includes a first functional group,
The concentration of the charge transporting material is higher in a region of the mixed layer where the light emitting layer is not present than in a region of the mixed layer where the light emitting layer is present,
The first dopant includes a third functional group,
The concentration of the first dopant is an organic light emitting device in which the region of the mixed layer on the side where the light emitting layer is present is higher than the region of the mixed layer where the light emitting layer is not present. In claim 1,
The difference in the concentration of the charge transporting material is an organic light emitting device that is generated by the charge transporting material moving to a region of the mixed layer where the light emitting layer is not present. In claim 1,
The first host includes a second functional group;
The organic light emitting device in which the concentration of the first host is higher in a region of the mixed layer where the light emitting layer is present than in a region of the mixed layer where the light emitting layer is not present. A lower electrode;
An upper electrode;
An organic light emitting device having a light emitting layer and a mixed layer disposed between the lower electrode and the upper electrode,
The mixed layer includes a first host, a first dopant, and a charge transport material,
The light emitting layer includes a second host,
The charge transport material includes a first functional group,
The concentration of the charge transporting material is higher in a region of the mixed layer where the light emitting layer is not present than in a region of the mixed layer where the light emitting layer is present,
A charge transport layer is formed on the lower electrode;
The light emitting layer is formed on the charge transport layer;
The mixed layer is formed on the light emitting layer,
The upper electrode is formed on the mixed layer;
When the second host is a material having a high hole transporting property, the first host or the first dopant includes one of a phenylamino group, a carbazole group, and a hydrazone group,
When the second host is a material having a high electron transporting property, the first host or the first dopant includes one of an oxadiazole group, a triazole group, and a phenanthroline group,
In the case where the second host is a material having a high hole transporting property and electron transporting property, the first host or the first dopant is a hydroxy group (—OH), a thiol group (—SH), a carboxyl group (— COOH), an organic light emitting device containing one of sulfo groups (—SO ₃ H). In claim 4,
The first functional group is an organic light-emitting element including one of a fluoroalkyl group, a perfluoroalkyl group, an alkyl group (the number of C is 10 or more), a perfluoropolyether group, and a siloxy group. A lower electrode;
An upper electrode;
An organic light emitting device having a light emitting layer and a mixed layer disposed between the lower electrode and the upper electrode,
The mixed layer includes a first host, a first dopant, and a charge transport material,
The light emitting layer includes a second host,
The charge transport material includes a first functional group,
The concentration of the charge transporting material is higher in a region of the mixed layer where the light emitting layer is not present than in a region of the mixed layer where the light emitting layer is present,
A charge transport layer is formed on the lower electrode;
The mixed layer is formed on the charge transport layer;
The light emitting layer is formed on the mixed layer,
The upper electrode is formed on the light emitting layer;
When the charge transport layer is a hole transport layer, the first functional group includes one of a phenylamino group, a carbazole group, and a hydrazone group,
When the charge transport layer is an electron transport layer, the first functional group is an organic light emitting device including one of an oxadiazole group, a triazole group, and a phenanthroline group. In claim 6,
The first host or the first dopant includes one of a fluoroalkyl group, a perfluoroalkyl group, an alkyl group (the number of C is 10 or more), a perfluoropolyether group, and a siloxy group. Organic light-emitting device having a group. A lower electrode;
An upper electrode;
An organic light emitting device having a light emitting layer and a mixed layer disposed between the lower electrode and the upper electrode,
The mixed layer includes a first host, a first dopant, and a charge transport material,
The light emitting layer includes a second host,
The charge transport material includes a first functional group,
The concentration of the charge transporting material is higher in a region of the mixed layer where the light emitting layer is not present than in a region of the mixed layer where the light emitting layer is present,
The light emitting layer includes a second dopant and a third dopant,
The emission color of the second dopant is different from the emission color of the first dopant,
The organic light-emitting element in which the emission color of the third dopant is different from the emission color of the first dopant and the emission color of the second dopant. In claim 8,
The organic light emitting element whose luminescent color of said 1st dopant is blue. A lower electrode;
An upper electrode;
An organic light emitting device having a first mixed layer and a second mixed layer disposed between the lower electrode and the upper electrode,
The first mixed layer includes a first host, a first dopant and a charge transport material,
The charge transport material includes a first functional group,
The second mixed layer includes at least a second host, a second dopant, and a third dopant,
The third dopant includes a seventh functional group,
The concentration of the charge transporting material is higher in a region of the first mixed layer in which the second mixed layer is not present than in a region of the first mixed layer in which the second mixed layer is present. Is higher,
The concentration of the third dopant is higher in the region of the second mixed layer in which the first mixed layer is present than in the region of the second mixed layer in which the first mixed layer is not present. Higher organic light emitting device. In claim 10,
The difference in the concentration of the charge transporting material is caused by the charge transporting material moving to a region of the first mixed layer where the second mixed layer is not present,
The difference in the concentration of the third dopant is an organic light-emitting element that is generated when the third dopant moves to a region of the second mixed layer where the first mixed layer is present. In claim 10,
The first dopant includes a third functional group,
The concentration of the first dopant is higher than that in the region where the second mixed layer is present in the first mixed layer than in the region where the second mixed layer is not present in the first mixed layer. Higher organic light emitting device. In claim 10,
The first host includes a second functional group;
The concentration of the first host is higher than the region of the first mixed layer where the second mixed layer is present than the region of the first mixed layer where the second mixed layer is not present. Higher organic light emitting device. In claim 10,
The second dopant includes a sixth functional group,
The concentration of the second dopant is higher than that in the region where the first mixed layer is not present in the second mixed layer than in the region where the first mixed layer is present in the second mixed layer. Higher organic light emitting device. In claim 10,
The second mixed layer includes a third host;
The third host includes an eighth functional group;
The concentration of the third host is higher in the region of the second mixed layer where the first mixed layer is not present than in the region of the second mixed layer where the first mixed layer is present. Higher organic light emitting device.   A light source device comprising the organic light emitting device according to claim 1. A method for producing an organic light emitting device comprising a lower electrode, an upper electrode, and a light emitting layer and a mixed layer disposed between the lower electrode and the upper electrode,
The mixed layer includes a first host, a first dopant, and a charge transport material,
The light emitting layer includes a second host,
The charge transport material includes a first functional group,
The concentration of the charge transporting material is higher in a region of the mixed layer where the light emitting layer is not present than in a region of the mixed layer where the light emitting layer is present,
The first dopant includes a third functional group,
The concentration of the first dopant is higher in the region of the mixed layer where the light emitting layer is present than in the region of the mixed layer where the light emitting layer is not present,
The said light emitting layer and mixed layer are the manufacturing methods of the organic light emitting element produced by application | coating. A method for producing an organic light emitting device comprising a lower electrode, an upper electrode, and a light emitting layer and a mixed layer disposed between the lower electrode and the upper electrode,
The mixed layer includes a first host, a first dopant, and a charge transport material,
The light emitting layer includes a second host,
The charge transport material includes a first functional group,
The concentration of the charge transporting material is higher in a region of the mixed layer where the light emitting layer is not present than in a region of the mixed layer where the light emitting layer is present,
The light emitting layer includes a second dopant and a third dopant,
The emission color of the second dopant is different from the emission color of the first dopant,
The emission color of the third dopant is different from the emission color of the first dopant and the emission color of the second dopant,
The said light emitting layer and mixed layer are the manufacturing methods of the organic light emitting element produced by application | coating.