JP5025182B2 - LIGHT EMITTING ELEMENT, LIGHT EMITTING DEVICE, AND ELECTRONIC DEVICE - Google Patents

Description

The present invention relates to a current excitation type light emitting element. In addition, the present invention relates to a light-emitting device and an electronic device each having a light-emitting element.

In recent years, research and development of light-emitting elements using light-emitting organic compounds have been actively conducted. The basic structure of these light-emitting elements is such that a layer containing a light-emitting organic compound is sandwiched between a pair of electrodes. By applying a voltage to this element, electrons and holes are respectively injected from the pair of electrodes into the layer containing a light-emitting organic compound, and a current flows. Then, these carriers (electrons and holes) recombine, whereby the light-emitting organic compound forms an excited state, and emits light when the excited state returns to the ground state. Due to such a mechanism, such a light-emitting element is referred to as a current-excitation light-emitting element.

Note that the excited states formed by the organic compound can be singlet excited state or triplet excited state. Light emission from the singlet excited state is called fluorescence, and light emission from the triplet excited state is called phosphorescence. ing.

Such a light-emitting element is formed of an organic thin film having a thickness of, for example, about 0.1 μm. In addition, since the time from the injection of the carrier to the light emission is about 1 μsec or less, one of the features is that the response speed is very fast. These characteristics are considered suitable for flat panel display elements.

In addition, since these light-emitting elements are formed in a film shape, planar light emission can be easily obtained by forming a large-area element. This is a feature that is difficult to obtain with a point light source typified by an incandescent bulb or LED, or a line light source typified by a fluorescent lamp, and therefore has a high utility value as a surface light source applicable to illumination or the like.

  By the way, display devices to be incorporated into various information processing devices that have been rapidly developed in recent years have a particularly high demand for low power consumption. In order to achieve this, attempts have been made to reduce the driving voltage of light-emitting elements. Yes.

  For example, in Patent Document 1, an effect of reducing driving voltage is obtained by using a layer in which vanadium oxide and α-NPD are co-evaporated.

However, the layer in which vanadium oxide and α-NPD are co-deposited has an absorption spectrum peak in the visible light region of 400 nm to 800 nm. In particular, large absorption is shown around 150 nm to 500 nm which is a blue region. Therefore, there is a problem that light emission obtained from the light-emitting substance is absorbed by the layer in which vanadium oxide and α-NPD are co-deposited, resulting in low external extraction efficiency of light emission.
JP 2005-123095 A

  Therefore, an object of the present invention is to provide a light-emitting element with high light emission efficiency. Another object is to provide a light-emitting element with a low driving voltage. Further, it is an object to provide a light-emitting device with low power consumption by manufacturing a light-emitting device using a light-emitting element. Another object is to provide an electronic device with low power consumption by using a light-emitting device as a display portion.

  As a result of intensive studies, the present inventors have found that the problem can be solved by applying a composite material containing an organic compound and an inorganic compound.

That is, one light-emitting element of the present invention is provided between a pair of electrodes so as to be in contact with a layer including a composite material formed by combining the first organic compound and an inorganic compound, and a layer including the composite material. A layer containing a second organic compound, and the second organic compound is an organic compound having no absorption spectrum peak in a wavelength region of 450 nm to 800 nm when combined with an inorganic compound. .

  According to one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining a first organic compound and an inorganic compound between a first electrode and a second electrode, and a layer including a composite material The second organic compound includes a layer containing a second organic compound and a light emitting layer containing a light emitting material, and the second organic compound has an absorption spectrum in a wavelength region of 450 nm to 800 nm when combined with an inorganic compound. The light-emitting substance emits light when a voltage is applied so that the potential of the first electrode is higher than the potential of the second electrode.

  According to one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining a first organic compound and an inorganic compound between a first electrode and a second electrode, and a layer including a composite material A layer including a second organic compound provided in contact with the light-emitting layer and a light-emitting layer including a light-emitting substance, and the layer including the composite material is provided in contact with the first electrode; , An organic compound that does not have an absorption spectrum peak in the wavelength region of 450 nm to 800 nm when combined with the inorganic compound, and the voltage is such that the potential of the first electrode is higher than the potential of the second electrode. The luminescent material emits light when sapphire is applied.

  In a light-emitting element of the present invention, a second layer provided between a pair of electrodes is in contact with a layer including a composite material formed by combining a first organic compound and an inorganic compound, and a layer including the composite material. The layer containing the organic compound is laminated, and the laminate does not have an absorption spectrum peak in a wavelength region of 450 nm to 800 nm.

  In a light-emitting element of the present invention, a second layer provided between a pair of electrodes is in contact with a layer including a composite material formed by combining a first organic compound and an inorganic compound, and a layer including the composite material. And a layered body in which a layer containing the organic compound is laminated, and in the wavelength region of 450 nm to 800 nm, the composite material has a transmittance of 80% or more when the film thickness is 100 nm, and the second organic compound and A composite material formed by combining an inorganic compound has a transmittance of 80% or more when the film thickness is 100 nm.

In a light-emitting element of the present invention, a second layer provided between a pair of electrodes is in contact with a layer including a composite material formed by combining a first organic compound and an inorganic compound, and a layer including the composite material. And the second organic compound and the inorganic compound satisfy the relationship expressed by the formula (1) in the wavelength region of 450 nm to 800 nm. The absorbance of the composite material formed by combining the two satisfies the relationship expressed by the formula (1).

  According to one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining a first organic compound and an inorganic compound between a first electrode and a second electrode, and a layer including a composite material A stacked body in which a layer including a second organic compound and a light-emitting layer including a light-emitting substance provided so as to be in contact with each other and a layer including a composite material and a layer including a second organic compound are stacked, The luminescent substance emits light when a voltage is applied such that the first electrode has a higher potential than the second electrode without having an absorption spectrum peak in the wavelength region of 450 nm to 800 nm. Features.

  According to one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining a first organic compound and an inorganic compound between a first electrode and a second electrode, and a layer including a composite material In the wavelength region of 450 nm to 800 nm, the composite material has a transmittance of 80 nm when the film thickness is 100 nm in a wavelength region of 450 nm to 800 nm. %, And the composite material formed by combining the second organic compound and the inorganic compound has a transmittance of 80% or more when the film thickness is 100 nm, and the potential of the first electrode is the second. The luminescent material emits light when a voltage is applied so as to be higher than the potential of the electrode.

  According to one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining a first organic compound and an inorganic compound between a first electrode and a second electrode, and a layer including a composite material A layer including a second organic compound provided in contact with the light-emitting layer and a light-emitting layer including a light-emitting substance, the layer including the composite material provided to be in contact with the first electrode, and a layer including the composite material; The stacked body in which the layer containing the second organic compound is stacked does not have an absorption spectrum peak in the wavelength region of 450 nm to 800 nm, and the potential of the first electrode is higher than the potential of the second electrode. The light-emitting substance emits light when a voltage is applied so as to increase.

  According to one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining a first organic compound and an inorganic compound between a first electrode and a second electrode, and a layer including a composite material A layer including a second organic compound provided in contact with the light-emitting layer and a light-emitting layer including a light-emitting substance, and the layer including the composite material is provided in contact with the first electrode and has a wavelength region of 450 nm to 800 nm. The composite material has a transmittance of 80% or more when the film thickness is 100 nm, and the composite material formed by combining the second organic compound and the inorganic compound has a transmittance of 80% when the film thickness is 100 nm. As described above, the light-emitting substance emits light when a voltage is applied so that the potential of the first electrode is higher than the potential of the second electrode.

According to one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining a first organic compound and an inorganic compound between a first electrode and a second electrode, and a layer including a composite material A layer including a second organic compound provided in contact with the light-emitting layer and a light-emitting layer including a light-emitting substance, and the layer including the composite material is provided in contact with the first electrode and has a wavelength region of 450 nm to 800 nm. In the above, the absorbance of the first composite material satisfies the relationship represented by the formula (1), and the absorbance of the composite material formed by combining the second organic compound and the inorganic compound satisfies the relationship represented by the formula (1). The light-emitting substance emits light when a voltage is applied so that the potential of the first electrode is higher than the potential of the second electrode.

  In the above structure, the first organic compound is preferably an aromatic hydrocarbon. In particular, an anthracene derivative is preferable.

  One of the light-emitting elements of the present invention is provided between a pair of electrodes so as to be in contact with a layer including a composite material formed by combining the first organic compound and an inorganic compound and the layer including the composite material. A layered body in which a layer containing a second organic compound is stacked is provided, and the first organic compound is an aromatic hydrocarbon.

  One of the light-emitting elements of the present invention is provided between a pair of electrodes so as to be in contact with a layer including a composite material formed by combining the first organic compound and an inorganic compound and a layer including the composite material. It has a stacked body in which a layer containing a second organic compound is stacked, and the first organic compound is an anthracene derivative.

より好ましくは、下記式で表される関係を満たすことが好ましい。

さらに好ましくは、下記式で表される関係を満たすことが好ましい。

In the above structure, the ionization potential of the second organic compound is larger than the ionization potential of the first organic compound, and the difference is preferably 0.5 eV or less. More preferably, it is 0.3 eV or less. More preferably, it is 0.1 eV or less. That is, when the ionization potential of the first organic compound is Ip (1) and the ionization potential of the second organic compound is Ip (2), it is preferable that the relationship represented by the following formula is satisfied.

More preferably, it is preferable to satisfy the relationship represented by the following formula.

More preferably, it is preferable to satisfy the relationship represented by the following formula.

  In the above structure, the second organic compound is preferably an aromatic hydrocarbon or a carbazole derivative. In particular, an anthracene derivative is preferable.

  In the above structure, the thickness of the layer containing the second organic compound is preferably 1 nm to 20 nm.

  In the above structure, the inorganic compound preferably exhibits an electron accepting property with respect to the first organic compound.

  The inorganic compound is preferably a transition metal oxide. In particular, an oxide of a metal belonging to Groups 4 to 8 in the periodic table is preferable. More preferably, any of vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide is preferable.

  One of the light-emitting elements of the present invention includes a layer including a composite material formed by combining an organic compound and an inorganic compound between a pair of electrodes, and an organic compound provided so as to be in contact with the layer including the composite material. And the composite material is characterized by having no absorption spectrum peak in a wavelength region of 450 nm to 800 nm.

  One of the light-emitting elements of the present invention includes a layer including a composite material formed by combining an organic compound and an inorganic compound between a pair of electrodes, and an organic compound provided so as to be in contact with the layer including the composite material. In the wavelength region of 450 nm to 800 nm, the transmittance when the thickness of the composite material is 100 nm is 80% or more.

In one embodiment of the light-emitting element of the present invention, a layer including a composite material obtained by combining an organic compound and an inorganic compound between a pair of electrodes, and the organic compound provided so as to be in contact with the layer including the composite material In the wavelength region of 450 nm to 800 nm, the absorbance of the composite material satisfies the relationship represented by formula (1).

  In one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining an organic compound and an inorganic compound and a layer including a composite material are in contact between the first electrode and the second electrode. The composite material has a layer containing an organic compound and a light-emitting layer containing a light-emitting substance, and the composite material does not have an absorption spectrum peak in the wavelength region of 450 nm to 800 nm, and the potential of the first electrode Is characterized in that the light-emitting substance emits light when a voltage is applied so as to be higher than the potential of the second electrode.

  In one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining an organic compound and an inorganic compound and a layer including a composite material are in contact between the first electrode and the second electrode. And having a layer containing an organic compound and a light emitting layer containing a light emitting substance, and having a transmittance of 80% or more when the thickness of the composite material is 100 nm in a wavelength region of 450 nm to 800 nm, The light-emitting substance emits light when a voltage is applied so that the potential of one electrode is higher than the potential of the second electrode.

  In one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining an organic compound and an inorganic compound and a layer including a composite material are in contact between the first electrode and the second electrode. A layer containing an organic compound and a light emitting layer containing a light emitting substance, the layer containing a composite material is provided so as to be in contact with the first electrode, and the composite material is in a wavelength region of 450 nm to 800 nm. The light-emitting substance emits light when a voltage is applied so that it does not have an absorption spectrum peak and the potential of the first electrode is higher than the potential of the second electrode.

  In one embodiment of the light-emitting element of the present invention, a layer including a composite material formed by combining an organic compound and an inorganic compound and a layer including a composite material are in contact between the first electrode and the second electrode. A layer containing an organic compound and a light emitting layer containing a light emitting substance, and the layer containing a composite material is provided so as to be in contact with the first electrode, and in the wavelength region of 450 nm to 800 nm, the composite material The light-emitting substance emits light when a voltage is applied such that the transmittance when the film thickness is 100 nm is 80% or more and the potential of the first electrode is higher than the potential of the second electrode. Features.

One of the light-emitting elements of the present invention is in contact with a layer including a composite material formed by combining an organic compound and an inorganic compound and a layer including the composite material between the first electrode and the second electrode. A layer containing an organic compound and a light-emitting layer containing a light-emitting substance, and the layer containing a composite material is provided so as to be in contact with the first electrode, and in the wavelength region of 450 nm to 800 nm, The absorbance satisfies the relationship represented by the formula (1), and the luminescent substance emits light when a voltage is applied so that the potential of the first electrode is higher than the potential of the second electrode. Light emitting element.

  In the above structure, the organic compound is preferably an aromatic hydrocarbon. In particular, an anthracene derivative is preferable.

  In one embodiment of the light-emitting element of the present invention, a layer including a composite material obtained by combining an organic compound and an inorganic compound between a pair of electrodes, and the organic compound provided so as to be in contact with the layer including the composite material And the organic compound is an aromatic hydrocarbon.

  One of the light-emitting elements of the present invention includes a layer including a composite material formed by combining an organic compound and an inorganic compound between a pair of electrodes, and an organic compound provided so as to be in contact with the layer including the composite material. And the organic compound is an anthracene derivative.

  In the above structure, the thickness of the layer containing an organic compound is preferably 1 nm to 20 nm.

  In the above structure, the inorganic compound preferably exhibits an electron accepting property with respect to the first organic compound.

  The inorganic compound is preferably a transition metal oxide. In particular, an oxide of a metal belonging to Groups 4 to 8 in the periodic table is preferable. More preferably, any of vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide is preferable.

  The present invention also includes a light emitting device having the above-described light emitting element. The light-emitting device in this specification includes an image display device, a light-emitting device, or a light source (including a lighting device). A panel in which a light emitting element is formed is provided with a connector such as an FPC (Flexible Printed Circuit) or TAB (Tape Automated Bonding) tape or TCP (Tape Carrier Package), or a printed wiring board at the end of a TAB tape or TCP. The light-emitting device also includes a module provided with an IC or an IC (integrated circuit) directly mounted on a light-emitting element by a COG (Chip On Glass) method.

  An electronic device using the light-emitting element of the present invention for the display portion is also included in the category of the present invention. Therefore, an electronic device according to the present invention includes a display portion, and the display portion includes the above-described light emitting element and a control unit that controls light emission of the light emitting element.

  By applying the present invention, a light-emitting element with high emission efficiency can be obtained.

  In addition, by applying the present invention, a light-emitting element driven at a low voltage can be obtained.

  In addition, by applying the present invention, a light-emitting device with low power consumption can be obtained.

  In addition, by applying the present invention, an electronic device with low power consumption can be obtained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

(Embodiment 1)
In this embodiment mode, a composite material used for the light-emitting element of the present invention will be described. Note that in this specification, the term “composite” means that not only two materials are mixed but also mixed at a molecular level so that charge can be transferred between the materials.

The composite material used in the present invention is a composite material formed by combining a first organic compound and an inorganic compound. As the first organic compound used for the composite material, various compounds such as an aromatic amine compound, a carbazole derivative, an aromatic hydrocarbon, and a high molecular compound (oligomer, dendrimer, polymer, or the like) can be used. Note that the first organic compound used for the composite material is preferably an organic compound having a high hole-transport property. Specifically, a substance having a hole mobility of 10 ⁻⁶ cm ² / Vs or higher is preferable. Note that other than these substances, any substance that has a property of transporting more holes than electrons may be used. Below, the 1st organic compound which can be used for a composite material is listed concretely.

  For example, as an aromatic amine compound, N, N′-di (p-tolyl) -N, N′-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4′-bis [N- (4- Diphenylaminophenyl) -N-phenylamino] biphenyl (abbreviation: DPAB), 4,4′-bis (N- {4- [N- (3-methylphenyl) -N-phenylamino] phenyl} -N-phenyl Amino) biphenyl (abbreviation: DNTPD), 1,3,5-tris [N- (4-diphenylaminophenyl) -N-phenylamino] benzene (abbreviation: DPA3B), and the like can be given.

  Specific examples of the carbazole derivative that can be used for the composite material include 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA1), 3 , 6-Bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA2), 3- [N- (1-naphthyl) -N- (9- Phenylcarbazol-3-yl) amino] -9-phenylcarbazole (abbreviation: PCzPCN1) and the like.

  In addition, 4,4′-di (N-carbazolyl) biphenyl (abbreviation: CBP), 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene (abbreviation: TCPB), 9- [4- ( N-carbazolyl)] phenyl-10-phenylanthracene (abbreviation: CzPA), 2,3,5,6-triphenyl-1,4-bis [4- (N-carbazolyl) phenyl] benzene, and the like can be used. .

As an aromatic hydrocarbon that can be used for the composite material, for example, 9,10-di (naphthalen-2-yl) -2-tert-butylanthracene (abbreviation: t-BuDNA), 9,10-di (Naphthalen-1-yl) -2-tert-butylanthracene, 9,10-bis (3,5-diphenylphenyl) anthracene (abbreviation: DPPA), 9,10-di (4-phenylphenyl) -2-tert -Butylanthracene (abbreviation: t-BuDBA), 9,10-di (naphthalen-2-yl) anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation) : T-BuAnth), 9,10-di (4-methylnaphthalen-1-yl) anthracene (abbreviation: DMNA), -Tert-butyl-9,10-bis [2- (naphthalen-1-yl) phenyl] anthracene, 9,10-bis [2- (naphthalen-1-yl) phenyl] anthracene, 2,3,6,7 -Tetramethyl-9,10-di (naphthalen-1-yl) anthracene, 2,3,6,7-tetramethyl-9,10-di (naphthalen-2-yl) anthracene, 9,9'-bianthryl, 10,10′-diphenyl-9,9′-bianthryl, 10,10′-di (2-phenylphenyl) -9,9′-bianthryl, 10,10′-bis [(2,3,4,5, 6-pentaphenyl) phenyl] -9,9′-bianthryl, anthracene derivatives such as anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra (tert-butyl) perylene, etc. It is below. In addition, pentacene, coronene, and the like can also be used. Thus, it is more preferable to use an aromatic hydrocarbon having a hole mobility of 1 × 10 ⁻⁶ cm ² / Vs or more and having 14 to 42 carbon atoms.

  Note that the aromatic hydrocarbon that can be used for the composite material may have a vinyl skeleton. As the aromatic hydrocarbon having a vinyl group, for example, 4,4′-bis (2,2-diphenylvinyl) biphenyl (abbreviation: DPVBi), 9,10-bis [4- (2,2- Diphenylvinyl) phenyl] anthracene (abbreviation: DPVPA) and the like.

  Alternatively, a high molecular compound such as poly (N-vinylcarbazole) (abbreviation: PVK) or poly (4-vinyltriphenylamine) (abbreviation: PVTPA) can be used.

  As the inorganic compound used for the composite material, a transition metal oxide is preferable. In addition, an oxide of a metal belonging to Groups 4 to 8 in the periodic table is preferable. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferable because of their high electron accepting properties. Among these, molybdenum oxide is particularly preferable because it is stable in the air, has a low hygroscopic property, and is easy to handle.

  Note that any method may be used for manufacturing the layer including the composite material regardless of a wet method or a dry method. For example, the layer including the composite material can be manufactured by co-evaporation of the organic compound and the inorganic compound described above. Moreover, it can also obtain by apply | coating and baking the solution containing the organic compound and metal alkoxide which were mentioned above. Molybdenum oxide is easy to evaporate in a vacuum and is preferable from the viewpoint of the manufacturing process.

  The composite material used in the present invention is a material having no absorption peak in the wavelength region of 450 nm to 800 nm. In addition, in the wavelength region of 450 nm to 800 nm, the composite material has a transmittance of 80% or more when the film thickness is 100 nm. Therefore, light emitted from the light emitting region can be efficiently extracted outside.

(Embodiment 2)
In this embodiment, a layer containing a second organic compound provided so as to be in contact with a composite material formed by combining the first organic compound and the inorganic compound described in Embodiment 1 will be described.

  The second organic compound contained in the layer containing the second organic compound provided in contact with the layer containing the composite material has an absorption peak in the wavelength region of 450 nm to 800 nm when combined with the inorganic compound contained in the composite material. It is an organic compound that does not have The composite material containing the inorganic compound and the second organic compound mixed at the same ratio as the mixing ratio of the first organic compound and the inorganic compound in the layer containing the composite material is a film in a wavelength region of 450 nm to 800 nm. The transmittance when the thickness is 100 nm is 80% or more.

As the second organic compound, various compounds such as an aromatic amine compound, a carbazole derivative, an aromatic hydrocarbon, and a polymer compound (oligomer, dendrimer, polymer, etc.) can be used. Note that the second organic compound is preferably an organic compound having a high hole-transport property. Specifically, a substance having a hole mobility of 10 ⁻⁶ cm ² / Vs or higher is preferable. Note that other than these substances, any substance that has a property of transporting more holes than electrons may be used. Hereinafter, the second organic compound is specifically listed.

  For example, as an aromatic amine compound, N, N′-di (p-tolyl) -N, N′-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4′-bis [N- (4- Diphenylaminophenyl) -N-phenylamino] biphenyl (abbreviation: DPAB), 4,4′-bis (N- {4- [N- (3-methylphenyl) -N-phenylamino] phenyl} -N-phenyl Amino) biphenyl (abbreviation: DNTPD), 1,3,5-tris [N- (4-diphenylaminophenyl) -N-phenylamino] benzene (abbreviation: DPA3B), and the like can be given.

  As a carbazole derivative, specifically, 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis [ N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA2), 3- [N- (1-naphthyl) -N- (9-phenylcarbazole-3- Yl) amino] -9-phenylcarbazole (abbreviation: PCzPCN1) and the like.

  In addition, 4,4′-di (N-carbazolyl) biphenyl (abbreviation: CBP), 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene (abbreviation: TCPB), 9- [4- ( N-carbazolyl)] phenyl-10-phenylanthracene (abbreviation: CzPA), 2,3,5,6-triphenyl-1,4-bis [4- (N-carbazolyl) phenyl] benzene, and the like can be used. .

Examples of the aromatic hydrocarbon include 9,10-di (naphthalen-2-yl) -2-tert-butylanthracene (abbreviation: t-BuDNA) and 9,10-di (naphthalen-1-yl). 2-tert-butylanthracene, 9,10-bis (3,5-diphenylphenyl) anthracene (abbreviation: DPPA), 9,10-di (4-phenylphenyl) -2-tert-butylanthracene (abbreviation: t) -BuDBA), 9,10-di (naphthalen-2-yl) anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9 , 10-di (4-methylnaphthalen-1-yl) anthracene (abbreviation: DMNA), 2-tert-butyl-9,1 -Bis [2- (naphthalen-1-yl) phenyl] anthracene, 9,10-bis [2- (naphthalen-1-yl) phenyl] anthracene, 2,3,6,7-tetramethyl-9,10- Di (naphthalen-1-yl) anthracene, 2,3,6,7-tetramethyl-9,10-di (naphthalen-2-yl) anthracene, 9,9′-bianthryl, 10,10′-diphenyl-9 , 9'-Bianthryl, 10,10'-di (2-phenylphenyl) -9,9'-bianthryl, 10,10'-bis [(2,3,4,5,6-pentaphenyl) phenyl]- Examples include anthracene derivatives such as 9,9′-bianthryl and anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra (tert-butyl) perylene, and the like. In addition, pentacene, coronene, and the like can also be used. Thus, it is more preferable to use an aromatic hydrocarbon having a hole mobility of 1 × 10 ⁻⁶ cm ² / Vs or more and having 14 to 42 carbon atoms.

  The aromatic hydrocarbon may have a vinyl skeleton. As the aromatic hydrocarbon having a vinyl group, for example, 4,4′-bis (2,2-diphenylvinyl) biphenyl (abbreviation: DPVBi), 9,10-bis [4- (2,2- Diphenylvinyl) phenyl] anthracene (abbreviation: DPVPA) and the like.

  Alternatively, a high molecular compound such as poly (N-vinylcarbazole) (abbreviation: PVK) or poly (4-vinyltriphenylamine) (abbreviation: PVTPA) can be used.

  The layer containing the second organic compound does not have an absorption spectrum peak in the wavelength region of 450 nm to 800 nm when combined with the inorganic compound included in the composite material. Further, the transmittance per 100 nm is 80% or more in a wavelength region of 450 nm to 800 nm when compounded with an inorganic compound so as to have the same ratio as the mixing ratio of the first organic compound and the inorganic compound in the layer containing the composite material. It is. Therefore, when the layer containing the composite material and the layer containing the second organic compound are in contact with each other, the layer containing the composite material is included in the interface between the layer containing the composite material and the layer containing the second organic compound. Even when the inorganic compound and the second organic compound are in contact with each other and exist as a composite material, light can be efficiently transmitted without absorbing light emitted from the light-emitting substance, and external extraction efficiency can be improved. That is, a light emitting element with high luminous efficiency can be obtained.

(Embodiment 3)
The light-emitting element of the present invention has a plurality of layers between a pair of electrodes. The plurality of layers have a high carrier injection property and carrier transport so that a light emitting region is formed at a position away from the electrode, that is, a carrier (carrier) is recombined at a position away from the electrode. The layers are formed by combining layers made of highly specific materials.

  One embodiment of a light-emitting element of the present invention is described below with reference to FIG.

  In this embodiment, the light-emitting element includes a first electrode 102, a first layer 103, a second layer 104, a third layer 105, and a fourth layer 106 that are sequentially stacked over the first electrode 102. And a second electrode 107 provided thereon. Note that in this embodiment mode, the first electrode 102 functions as an anode and the second electrode 107 functions as a cathode.

  The substrate 101 is used as a support for the light emitting element. As the substrate 101, for example, glass or plastic can be used. Note that other materials may be used as long as the light-emitting element functions as a support in the manufacturing process.

  As the first electrode 102, various metals, alloys, electrically conductive compounds, and mixtures thereof can be used. For example, indium tin oxide (ITO), indium tin oxide containing silicon, IZO (Indium Zinc Oxide) in which 2 to 20 wt% zinc oxide (ZnO) is mixed with indium oxide, gold ( Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), titanium (Ti), copper (Cu), palladium ( Pd), aluminum (Al), aluminum-silicon (Al-Si), aluminum-titanium (Al-Ti), aluminum-silicon-copper (Al-Si-Cu), or a nitride of metal material (TiN), etc. However, when the first electrode is used as an anode, the work function is high (work It is preferably formed by such as the number 4.0eV or higher).

  Note that in the light-emitting element of the present invention, the first electrode 102 is not limited to a material having a high work function, and a material having a low work function can also be used.

  The first layer 103 is a layer including the composite material described in Embodiment 1. That is, the layer includes a composite material in which the first organic compound and the inorganic compound are combined.

  The composite material included in the first layer 103 does not have an absorption spectrum peak in a wavelength region of 450 nm to 800 nm. Further, the composite material included in the first layer 103 has a transmittance of 80% or more when the film thickness is 100 nm over the entire wavelength region of 450 nm to 800 nm. Therefore, light emitted from the light-emitting substance can be efficiently transmitted and external extraction efficiency can be improved. That is, a light emitting element with high luminous efficiency can be obtained.

  Note that any method may be used for manufacturing the layer including the composite material regardless of a wet method or a dry method. For example, the layer including the composite material can be manufactured by co-evaporation of the organic compound and the inorganic compound described above. Moreover, it can also obtain by apply | coating and baking the solution containing the organic compound and metal alkoxide which were mentioned above. Molybdenum oxide is easy to evaporate in a vacuum and is preferable from the viewpoint of the manufacturing process.

  The second layer 104 is a layer including the second organic compound described in Embodiment 2. That is, it is a layer that includes the second organic compound that does not have an absorption spectrum peak in the wavelength region of 450 nm to 800 nm when combined with the inorganic compound included in the composite material included in the first layer 103.

より好ましくは、下記式で表される関係を満たすことが好ましい。

さらに好ましくは、下記式で表される関係を満たすことが好ましい。

Note that the ionization potential of the second organic compound included in the second layer 104 is larger than the ionization potential of the first organic compound included in the first layer 103, and the difference is 0.5 eV or less. Is preferred. More preferably, it is 0.3 eV or less. More preferably, it is 0.1 eV or less. That is, when the ionization potential of the first organic compound is Ip (1) and the ionization potential of the second organic compound is Ip (2), it is preferable that the relationship represented by the following formula is satisfied.

More preferably, it is preferable to satisfy the relationship represented by the following formula.

More preferably, it is preferable to satisfy the relationship represented by the following formula.

  Since the ionization potential of the second organic compound and the ionization potential of the first organic compound satisfy the above formula, the carrier injection barrier from the first layer 103 to the second layer 104 is reduced. The driving voltage can be reduced. Therefore, when an organic compound having a high ionization potential such as an aromatic hydrocarbon is used as the first organic compound included in the first layer 103, the second organic compound that can be used for the second layer 104 is used. As a result, the range of ionization potentials of the second organic compound is expanded. For example, an aromatic hydrocarbon can be used as the first organic compound included in the first layer 103, and an aromatic hydrocarbon can be used as the second organic compound included in the second layer 104. In this manner, a light-emitting element that does not contain an amine compound can be manufactured.

  Table 1 shows specific measurement values of ionization potentials of compounds that can be used as the first organic compound or the second organic compound.

  In this specification, photoelectron spectroscopy in the atmosphere is used as a method for measuring the ionization potential. For example, as an apparatus used for such measurement, there are AC-2 and Riken Keiki Co., Ltd. As a measurement object, a thin film formed on a glass substrate by a vapor deposition method was used.

  When aromatic hydrocarbon is used as the first organic compound contained in the first layer 103 and aromatic hydrocarbon is used as the second organic compound contained in the second layer 104, light emission with high heat resistance is achieved. An element can be manufactured. In general, when a bond between a heteroatom such as oxygen, nitrogen, or sulfur and carbon exists in the molecule, the flexibility of the molecular skeleton is improved, so that the thermal properties such as the glass transition temperature and the melting point are lowered. Therefore, if the molecular structure is similar, the aromatic hydrocarbon has higher thermal properties than the aromatic amine compound. Therefore, a light-emitting element with high heat resistance can be obtained by using an aromatic hydrocarbon as compared with the case of using an aromatic amine compound having a similar molecular structure.

  In addition, when a high glass transition temperature or a high melting point is imparted to the amine compound, it is necessary to increase the molecular weight. For this reason, starburst type amine compounds and linear oligoamine compounds have been synthesized so far, but these compounds have a large number of synthesis steps and the time required to obtain the desired material. Is long and expensive. Therefore, the use of aromatic hydrocarbons can reduce the cost required to obtain a light-emitting element having similar heat resistance.

  In addition, when the organic compounds included in the first layer 103 and the second layer 104 are the same substance, that is, when the first organic compound and the second organic compound are the same substance, the first layer 103 and the second layer 104 are preferable because the carrier injection barrier becomes small. In addition, in the case where the first layer 103 and the second layer 104 are formed by an evaporation method, it is possible to form a film continuously, so that the process can be simplified and productivity is further improved. be able to.

  Note that the thickness of the second layer 104 is preferably 1 nm to 20 nm.

Note that as illustrated in FIG. 3, a layer 108 containing a substance having a high hole-transport property may be provided between the second layer 104 and the third layer 105. As a substance having a high hole-transport property, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB or α-NPD), N, N′-bis (3 -Methylphenyl) -N, N′-diphenyl- [1,1′-biphenyl] -4,4′-diamine (abbreviation: TPD), 4,4 ′, 4 ″ -tris (N, N-diphenylamino) ) Triphenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 4,4′-bis An aromatic amine compound such as [N-phenyl-N- (spirofluoren-2-yl)] biphenyl (abbreviation: BSPB) (that is, a compound having a benzene ring-nitrogen bond) or the like can be used. The substances described here are mainly substances having a hole mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that other than these substances, any substance that has a property of transporting more holes than electrons may be used. Further, the layer containing a substance having a high hole-transport property is not limited to a single layer, and two or more layers containing the above substances may be stacked.

  The third layer 105 is a layer including a substance having a high light-emitting property. For example, N, N′-dimethylquinacridone (abbreviation: DMQd), N, N′-diphenylquinacridone (abbreviation: DPQd), 3- (2-benzothiazoyl) -7-diethylaminocoumarin (abbreviation: coumarin 6), etc. Highly luminescent substance and carrier transport properties such as tris (8-quinolinolato) aluminum (abbreviation: Alq) and 9,10-di (2-naphthyl) anthracene (abbreviation: DNA) are high and the film quality is good (that is, difficult to crystallize). ) Constructed by freely combining substances. However, since Alq and DNA are substances having high light-emitting properties, a structure in which these substances are used alone may be used as the third layer 105.

The fourth layer 106 is formed using a substance having a high electron-transport property, such as tris (8-quinolinolato) aluminum (abbreviation: Alq), tris (5-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ ), bis (10− Hydroxybenzo [h] -quinolinato) beryllium (abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) -4-phenylphenolato-aluminum (abbreviation: BAlq), and other metals having a quinoline skeleton or a benzoquinoline skeleton It is a layer made of a complex or the like. In addition, bis [2- (2-hydroxyphenyl) -benzoxazolate] zinc (abbreviation: Zn (BOX) ₂ ), bis [2- (2-hydroxyphenyl) -benzothiazolate] zinc (abbreviation: Zn ( A metal complex having an oxazole-based or thiazole-based ligand such as BTZ) ₂ ) can also be used. In addition to metal complexes, 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis [5 -(P-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 3- (4-tert-butylphenyl) -4-phenyl-5 (4-Biphenylyl) -1,2,4-triazole (abbreviation: TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2 , 4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), and the like can also be used. The substances mentioned here are mainly substances having an electron mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that a substance other than the above substances may be used for the fourth layer 106 as long as it has a property of transporting more electrons than holes. The fourth layer 106 is not limited to a single layer, and may be a stack of two or more layers formed using the above substances.

  As a material for forming the second electrode 107, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a low work function (a work function of 3.8 eV or less) can be used. Specific examples of such a cathode material include elements belonging to Group 1 or Group 2 of the periodic table of elements, that is, alkali metals such as lithium (Li) and cesium (Cs), and magnesium (Mg), calcium (Ca), Examples thereof include alkaline earth metals such as strontium (Sr) and alloys containing them (Mg: Ag, Al: Li). However, by providing a layer having a function of promoting electron injection between the second electrode 107 and the fourth layer 106 so as to be stacked with the second electrode, Al can be obtained regardless of the work function. Various conductive materials such as Ag, ITO, and ITO containing silicon can be used for the second electrode 107.

Note that as a layer having a function of promoting electron injection, an alkali metal or alkaline earth metal compound such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ₂ ), or the like is used. Can do. In addition, a layer made of a substance having an electron transporting property containing an alkali metal or an alkaline earth metal, for example, a layer containing magnesium (Mg) in Alq can be used.

  Further, the first layer 103, the second layer 104, the third layer 105, and the fourth layer 106 may be formed by a method other than the above evaporation method. For example, an ink jet method or a spin coating method may be used. Moreover, you may form using the different film-forming method for each electrode or each layer.

  The light-emitting element of the present invention having the above structure is a third layer that contains a highly light-emitting substance because a current flows due to a potential difference generated between the first electrode 102 and the second electrode 107. In the layer 105, holes and electrons recombine to emit light. That is, a light emitting region is formed in the third layer 105. However, it is not necessary that all of the third layer 105 functions as a light emitting region. For example, the light emitting region is formed only on the second layer 104 side or the fourth layer 106 side of the third layer 105. It may be anything.

  Light emission is extracted outside through one or both of the first electrode 102 and the second electrode 107. Therefore, one or both of the first electrode 102 and the second electrode 107 is formed using a light-transmitting substance. In the case where only the first electrode 102 is formed using a light-transmitting substance, light emission is extracted from the substrate side through the first electrode 102 as illustrated in FIG. In the case where only the second electrode 107 is formed using a light-transmitting substance, light emission is extracted from the side opposite to the substrate through the second electrode 107 as illustrated in FIG. In the case where both the first electrode 102 and the second electrode 107 are made of a light-transmitting substance, light is emitted from the first electrode 102 and the second electrode 107 as shown in FIG. And is taken out from both the substrate side and the opposite side of the substrate.

  Note that the structure of the layers provided between the first electrode 102 and the second electrode 107 is not limited to the above. A structure in which holes and electrons are recombined in a portion away from the first electrode 102 and the second electrode 107 so that quenching caused by the proximity of the light emitting region and the metal is suppressed. A second layer that includes a composite material in which the first organic compound and the inorganic compound are combined, and a second layer that does not have an absorption spectrum peak in a wavelength region of 450 nm to 800 nm when combined with the inorganic compound included in the composite material. Any other layer may be used as long as it is in contact with the layer containing the organic compound.

In other words, the layered structure of the layers is not particularly limited, and a substance having a high electron transporting property or a substance having a high hole transporting property, a substance having a high electron injecting property, a substance having a high hole injecting property, or a bipolar property (electron and hole) When a layer made of a substance having a high transportability) is combined with a layer containing a composite material in which the first organic compound and an inorganic compound are composited and an inorganic compound contained in the composite material, the wavelength region is 450 nm to 800 nm. And a layer containing a second organic compound that does not have an absorption spectrum peak.

  A light-emitting element illustrated in FIG. 2 includes a first layer 303 made of a substance having a high electron-transport property, a second layer 304 containing a substance having a high light-emitting property, a fourth layer, A third layer 305 which is a layer containing a second organic compound having no absorption spectrum peak in a wavelength region of 450 nm to 800 nm when combined with an inorganic compound included in the composite material of the layer 306; A fourth layer 306 which is a layer including a composite material in which an inorganic compound is combined and a second electrode 307 functioning as an anode are sequentially stacked. Reference numeral 301 denotes a substrate.

  In this embodiment mode, a light-emitting element is manufactured over a substrate made of glass, plastic, or the like. A passive light-emitting device can be manufactured by manufacturing a plurality of such light-emitting elements over one substrate. In addition to a substrate made of glass, plastic, or the like, a light emitting element may be manufactured on a thin film transistor (TFT) array substrate, for example. Thus, an active matrix light-emitting device in which driving of the light-emitting element is controlled by the TFT can be manufactured. Note that the structure of the TFT is not particularly limited. A staggered TFT or an inverted staggered TFT may be used. Also, the driving circuit formed on the TFT array substrate may be composed of N-type and P-type TFTs, or may be composed of only one of N-type and P-type. Further, the crystallinity of a semiconductor film used for the TFT is not particularly limited. An amorphous semiconductor film or a crystalline semiconductor film may be used.

  The light-emitting element of the present invention does not have a peak of an absorption spectrum in a wavelength region of 450 nm to 800 nm when combined with a layer including a composite material in which the first organic compound and the inorganic compound are combined and an inorganic compound included in the composite material. A layer containing a second organic compound;

  The layer containing the composite material does not have an absorption spectrum peak in the wavelength region of 450 nm to 800 nm. Therefore, light emitted from the light-emitting substance can be efficiently transmitted and external extraction efficiency can be improved. That is, a light emitting element with high luminous efficiency can be obtained.

  The layer containing the second organic compound does not have an absorption spectrum peak in the wavelength region of 450 nm to 800 nm when combined with the inorganic compound included in the composite material. Therefore, when the first layer 103 and the second layer 104 are in contact with each other, an inorganic compound included in the layer including the composite material at the interface between the layer including the composite material and the layer including the second organic compound. And the second organic compound are in contact with each other and exist as a composite material, the light can be efficiently transmitted without absorbing light emitted from the light-emitting substance, and external extraction efficiency can be improved. That is, a light emitting element with high luminous efficiency can be obtained.

  In addition, the layer including the composite material in which the first organic compound and the inorganic compound are combined has high conductivity. Therefore, low voltage driving of the light emitting element can be realized.

  In addition, since a layer including a composite material in which an organic compound and an inorganic compound are combined has high conductivity, an increase in driving voltage can be suppressed even when the layer including the composite material is thickened. Therefore, it is possible to optimize the thickness of the layer including the composite material so that the efficiency of extracting light to the outside is increased while suppressing an increase in driving voltage.

  In addition, the color purity can be improved by optical design without increasing the driving voltage.

  In addition, by increasing the thickness of the layer including the composite material, a short circuit due to unevenness or impact on the electrode can be prevented; thus, a highly reliable light-emitting element can be obtained. For example, the film thickness between electrodes of a normal light-emitting element is 100 nm to 150 nm, whereas the film thickness between electrodes of a light-emitting element using a layer containing a composite material is 100 to 500 nm, preferably 200 to 500 nm. It can be.

  In addition, the layer containing the composite material used for the light-emitting element of the present invention can be in ohmic contact with the electrode and has low contact resistance with the electrode. Therefore, the electrode material can be selected without considering the work function or the like. That is, the choice of electrode material is expanded.

(Embodiment 4)
In this embodiment mode, a light-emitting device having the light-emitting element of the present invention will be described.

  In this embodiment mode, a light-emitting device having the light-emitting element of the present invention in a pixel portion will be described with reference to FIG. Note that FIG. 33A is a top view illustrating the light-emitting device, and FIG. 33B is a cross-sectional view taken along lines A-A ′ and B-B ′ of FIG. Reference numeral 601 indicated by a dotted line denotes a driving circuit portion (source side driving circuit), 602 denotes a pixel portion, and 603 denotes a driving circuit portion (gate side driving circuit). Reference numeral 604 denotes a sealing substrate, reference numeral 605 denotes a sealing material, and the inside surrounded by the sealing material 605 is a space 607.

  Note that the routing wiring 608 is a wiring for transmitting a signal input to the source side driving circuit 601 and the gate side driving circuit 603, and a video signal, a clock signal, an FPC (flexible printed circuit) 609 serving as an external input terminal, Receives start signal, reset signal, etc. Although only the FPC is shown here, a printed wiring board (PWB) may be attached to the FPC. The light-emitting device in this specification includes not only a light-emitting device body but also a state in which an FPC or a PWB is attached thereto.

  Next, a cross-sectional structure will be described with reference to FIG. A driver circuit portion and a pixel portion are formed over the element substrate 610. Here, a source-side driver circuit 601 that is a driver circuit portion and one pixel in the pixel portion 602 are illustrated.

  Note that the source side driver circuit 601 is a CMOS circuit in which an n-channel TFT 623 and a p-channel TFT 624 are combined. The TFT forming the driving circuit may be formed by various CMOS circuits, PMOS circuits, or NMOS circuits. In this embodiment, a driver integrated type in which a drive circuit is formed on a substrate is shown, but this is not always necessary, and the drive circuit can be formed outside the substrate.

  The pixel portion 602 is formed by a plurality of pixels including a switching TFT 611, a current control TFT 612, and a first electrode 613 electrically connected to the drain thereof. Note that an insulator 614 is formed so as to cover an end portion of the first electrode 613. Here, a positive photosensitive acrylic resin film is used.

  In order to improve the coverage, a curved surface having a curvature is formed at the upper end or the lower end of the insulator 614. For example, when positive photosensitive acrylic is used as a material for the insulator 614, it is preferable that only the upper end portion of the insulator 614 has a curved surface with a curvature radius (0.2 μm to 3 μm). As the insulator 614, either a negative type that becomes insoluble in an etchant by light irradiation or a positive type that becomes soluble in an etchant by light irradiation can be used.

  Over the first electrode 613, a layer 616 containing a light-emitting substance and a second electrode 617 are formed. Here, as a material used for the first electrode 613 functioning as an anode, various metals, alloys, electrically conductive compounds, and mixtures thereof can be used. In the case where the first electrode is used as an anode, it is preferable that the first electrode is formed with a large work function (work function of 4.0 eV or more). For example, indium tin oxide containing silicon, IZO (Indium Zinc Oxide) in which 2 to 20 wt% zinc oxide (ZnO) is mixed with indium oxide, titanium nitride film, chromium film, tungsten film, Zn film, Pt film, etc. In addition to the single layer film, a stack of titanium nitride and a film containing aluminum as a main component, a three-layer structure of a titanium nitride film, a film containing aluminum as a main component, and a titanium nitride film can be used. Note that with a stacked structure, resistance as a wiring is low, good ohmic contact can be obtained, and a function as an anode can be obtained.

  The layer 616 containing a light-emitting substance is formed by various methods such as an evaporation method using an evaporation mask, an inkjet method, and a spin coating method. The layer 616 containing a light-emitting substance includes the layer containing the composite material shown in Embodiment Mode 1 and the layer containing the second organic compound shown in Embodiment Mode 2. In addition, the other material forming the layer 616 containing a light-emitting substance may be a low molecular material, a medium molecular material (including an oligomer or a dendrimer), or a high molecular material. In addition, as a material used for a layer containing a light-emitting substance, an organic compound is usually used in a single layer or a stacked layer. I will do it.

  Further, as a material used for the second electrode 617 which is formed over the light-emitting substance-containing layer 616 and functions as a cathode, a metal, an alloy, an electrically conductive compound, and a low work function (work function of 3.8 eV or less) These mixtures can be used. Specific examples of such cathode materials include elements belonging to Group 1 or Group 2 of the periodic table of elements, that is, alkali metals such as lithium (Li) and cesium (Cs), and magnesium (Mg) and calcium (Ca ), Alkaline earth metals such as strontium (Sr), and alloys containing these (Mg: Ag, Al: Li). Note that in the case where light generated in the layer 616 containing a light-emitting substance passes through the second electrode 617, the second electrode 617 includes a thin metal film and a transparent conductive film (ITO, 2 to 20 wt. % Of indium oxide containing zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), or the like is preferably used.

  Further, the sealing substrate 604 is bonded to the element substrate 610 with the sealant 605, whereby the light-emitting element 618 is provided in the space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealant 605. Yes. Note that the space 607 is filled with a filler, and may be filled with a sealant 605 in addition to an inert gas (such as nitrogen or argon).

  Note that an epoxy-based resin is preferably used for the sealant 605. Moreover, it is desirable that these materials are materials that do not transmit moisture and oxygen as much as possible. In addition to a glass substrate or a quartz substrate, a plastic substrate made of FRP (Fiberglass-Reinforced Plastics), PVF (polyvinyl fluoride), Mylar, polyester, acrylic, or the like can be used as a material for the sealing substrate 604.

  As described above, a light-emitting device having the light-emitting element of the present invention can be obtained.

  The light-emitting device of the present invention includes a layer including the composite material described in Embodiment 1 and a layer including the second organic compound described in Embodiment 2 provided so as to be in contact with the layer including the composite material. ing. Therefore, the light emitted from the light emitting region can be efficiently extracted outside, and the light emission efficiency is high. In addition, the driving voltage can be reduced and the power consumption can be reduced.

  In addition, the light-emitting device of the present invention can suppress an increase in driving voltage even if the layer containing the composite material is thickened. Therefore, the layer containing the composite material can be thickened to prevent a short circuit of the light-emitting element. In addition, it is possible to realize an improvement in the efficiency of taking out emitted light by optical design. Thus, a light-emitting device with low power consumption and high reliability can be obtained.

  As described above, in this embodiment mode, an active light-emitting device that controls driving of a light-emitting element using a transistor has been described. In addition to this, a light-emitting element is driven without particularly providing a driving element such as a transistor. A passive light emitting device may be used. FIG. 34 is a perspective view of a passive light emitting device manufactured by applying the present invention. In FIG. 34, a layer 955 containing a light-emitting substance is provided between the electrode 952 and the electrode 956 over the substrate 951. An end portion of the electrode 952 is covered with an insulating layer 953. A partition layer 954 is provided over the insulating layer 953. The side wall of the partition wall layer 954 has an inclination such that the distance between one side wall and the other side wall becomes narrower as it approaches the substrate surface. That is, the cross section in the short side direction of the partition wall layer 954 has a trapezoidal shape, and the bottom side (the side facing the insulating layer 953 in the same direction as the surface direction of the insulating layer 953) is the top side (the surface of the insulating layer 953). The direction is the same as the direction and is shorter than the side not in contact with the insulating layer 953. In this manner, by providing the partition layer 954, defects in the light-emitting element due to static electricity or the like can be prevented. A passive light-emitting device can also be driven with low power consumption by including the light-emitting element of the present invention that has high luminous efficiency and operates at a low driving voltage.

(Embodiment 5)
In this embodiment, an electronic device of the present invention including the light-emitting device described in Embodiment 4 as part thereof will be described. The electronic device of the present invention includes a layer including the composite material described in Embodiment 1 and a layer including the second organic compound described in Embodiment 2 provided so as to be in contact with the layer including the composite material. And a display portion with low power consumption. Further, by providing a thick layer including the composite material described in Embodiment 1, an electronic device including a highly reliable display portion in which a short circuit due to a minute foreign matter or an external impact is suppressed is provided. It is also possible to do.

As an electronic device manufactured using the light emitting device of the present invention, a video camera, a digital camera, a goggle type display, a navigation system, a sound reproducing device (car audio, audio component, etc.), a computer, a game device, a portable information terminal (mobile) Display device capable of playing back a recording medium such as a computer, a mobile phone, a portable game machine, or an electronic book) and a recording medium (specifically, a digital versatile disc (DVD)) and displaying the image And the like). Specific examples of these electronic devices are shown in FIGS.
FIG. 35A illustrates a television device according to the present invention, which includes a housing 9101, a supporting base 9102, a display portion 9103, a speaker portion 9104, a video input terminal 9105, and the like. In this television device, the display portion 9103 is formed by arranging light-emitting elements similar to those described in Embodiment Modes 2 to 6 in a matrix. The light-emitting element has a feature of high luminous efficiency and low driving voltage. It is also possible to prevent a short circuit due to a minute foreign matter or an external impact. Since the display portion 9103 including the light-emitting elements has similar features, this television set has no deterioration in image quality and low power consumption. With such a feature, in the television device, the circuit for the deterioration compensation function and the power supply circuit can be significantly reduced, or the size of the circuit for the deterioration compensation function and the power supply circuit can be reduced. It is possible to reduce the size and weight. In the television device according to the present invention, low power consumption, high image quality, and reduction in size and weight are achieved, so that a product suitable for a living environment can be provided.

  FIG. 35B illustrates a computer according to the present invention, which includes a main body 9201, a housing 9202, a display portion 9203, a keyboard 9204, an external connection port 9205, a pointing mouse 9206, and the like. In this computer, the display portion 9203 includes light-emitting elements similar to those described in Embodiment Modes 2 to 6, arranged in a matrix. The light-emitting element has a feature of high luminous efficiency and low driving voltage. It is also possible to prevent a short circuit due to a minute foreign matter or an external impact. Since the display portion 9203 including the light-emitting elements has similar features, this computer has no deterioration in image quality and has low power consumption. With such a feature, the deterioration compensation function circuit and the power supply circuit can be greatly reduced in the computer, or the size of the deterioration compensation function circuit and the power supply circuit can be reduced. Can be achieved. In the computer according to the present invention, low power consumption, high image quality, and reduction in size and weight are achieved; therefore, a product suitable for the environment can be provided. Further, the computer can be carried, and a computer having a display portion that is resistant to external shocks when being carried can be provided.

  FIG. 35C illustrates a cellular phone according to the present invention, which includes a main body 9401, a housing 9402, a display portion 9403, an audio input portion 9404, an audio output portion 9405, operation keys 9406, an external connection port 9407, an antenna 9408, and the like. . In this cellular phone, the display portion 9403 is formed by arranging light-emitting elements similar to those described in Embodiment Modes 2 to 6 in a matrix. The light-emitting element has a feature of high luminous efficiency and low driving voltage. It is also possible to prevent a short circuit due to a minute foreign matter or an external impact. Since the display portion 9403 including the light-emitting elements has similar features, the cellular phone has no deterioration in image quality and low power consumption. With such a feature, the deterioration compensation function circuit and the power supply circuit can be significantly reduced or the size of the deterioration compensation function circuit and the power supply circuit can be reduced in the cellular phone. It is possible to reduce the weight. Since the cellular phone according to the present invention has low power consumption, high image quality, and reduced size and weight, a product suitable for carrying can be provided. In addition, a product having a display portion that is resistant to impact when carried can be provided.

  FIG. 35D illustrates a camera according to the present invention, which includes a main body 9501, a display portion 9502, a housing 9503, an external connection port 9504, a remote control receiving portion 9505, an image receiving portion 9506, a battery 9507, an audio input portion 9508, and operation keys 9509. , An eyepiece 9510 and the like. In this camera, the display portion 9502 includes light-emitting elements similar to those described in Embodiment Modes 2 to 6, arranged in a matrix. The light-emitting element has characteristics such that light emission efficiency is high, driving voltage is low, and short-circuiting due to minute foreign matters, external impact, or the like can be prevented. Since the display portion 9502 including the light-emitting elements has similar features, this camera has no deterioration in image quality and has low power consumption. With such a feature, in the camera, the deterioration compensation function circuit and the power supply circuit can be significantly reduced, or the size of the deterioration compensation function circuit and the power supply circuit can be reduced, so that the main body 9501 can be reduced in size and weight. Is possible. Since the camera according to the present invention has low power consumption, high image quality, and small size and light weight, a product suitable for carrying can be provided. In addition, a product having a display portion that is resistant to impact when carried can be provided.

  As described above, the applicable range of the light-emitting device of the present invention is so wide that the light-emitting device can be applied to electronic devices in various fields. By using the light-emitting device of the present invention, an electronic device having a display portion with low power consumption and high reliability can be provided.

  In addition, the light-emitting device of the present invention includes a light-emitting element with high emission efficiency, and can also be used as a lighting device. One mode in which the light-emitting element of the present invention is used as a lighting device is described with reference to FIG.

  FIG. 36 illustrates an example of a liquid crystal display device using the light-emitting device of the present invention as a backlight. The liquid crystal display device illustrated in FIG. 36 includes a housing 901, a liquid crystal layer 902, a backlight 903, and a housing 904, and the liquid crystal layer 902 is connected to a driver IC 905. The backlight 903 uses the light-emitting device of the present invention, and a current is supplied from a terminal 906.

  By using the light emitting device of the present invention as a backlight of a liquid crystal display device, a backlight with reduced power consumption can be obtained. Further, the light-emitting device of the present invention is a surface-emitting illumination device and can have a large area, so that the backlight can have a large area and a liquid crystal display device can have a large area. Further, since the light emitting device is thin and has low power consumption, the display device can be thinned and the power consumption can be reduced.

  In this example, an organic compound and an inorganic compound used for the light-emitting element of the present invention, a method for manufacturing a composite layer, and optical characteristics will be described.

(Sample 1)
First, a quartz substrate is fixed to a substrate holder in a vacuum deposition apparatus. Then, DNTPD and molybdenum oxide (VI) are put in separate resistance heating evaporation sources, then the inside of the vacuum apparatus is evacuated, and the pressure is reduced to about 10 ⁻⁴ Pa. A layer containing was formed. At this time, the co-evaporation was performed so that the weight ratio of DNTPD to molybdenum oxide was 2: 1. The film thickness was 100 nm.

FIG. 37 shows the result of measuring the absorption spectrum of the DNTPD-molybdenum oxide composite layer (sample 1) thus formed in the wavelength region of 450 nm to 800 nm. The transmittance is shown in FIG.

(Comparative Example 1)
(Comparative sample 2)
A quartz substrate is fixed to a substrate holder in a vacuum deposition apparatus. Then, NPB and molybdenum oxide (VI) are put in separate resistance heating type evaporation sources, then the inside of the vacuum apparatus is evacuated and decompressed to about 10 ⁻⁴ Pa, and then NPB and molybdenum oxide are formed by co-evaporation. A layer containing was formed. At this time, co-evaporation was performed so that the weight ratio of NPB to molybdenum oxide was 2: 0.75. The film thickness was 100 nm.

FIG. 37 shows the result of measuring the absorption spectrum in the wavelength region of 450 nm to 800 nm of the NPB-molybdenum oxide composite layer (Comparative Sample 2) thus formed. The transmittance is shown in FIG.

As can be seen from FIGS. 4 and 37, the DNTPD-molybdenum oxide composite layer does not show an absorption peak in the wavelength region of 450 nm to 800 nm and has a transmittance of 80% or more, whereas the NPB which is a comparative example -The molybdenum oxide mixed film has an absorption peak in the vicinity of 500 nm and has a wavelength region where the transmittance is less than 80%.

  Therefore, it can be seen that the composite material of the present invention and the organic compound layer provided in contact with the composite material do not have an absorption peak in the wavelength region of 450 nm to 800 nm and have high transmittance.

  In this example, a method for manufacturing a layer including an organic compound and an inorganic compound, and a composite material used for the light-emitting element of the present invention, and optical characteristics will be described.

(Sample 3)
First, a quartz substrate is fixed to a substrate holder in a vacuum deposition apparatus. Then, t-BuDNA and molybdenum oxide (VI) are put in separate resistance heating type evaporation sources, then the inside of the vacuum apparatus is evacuated, and the pressure is reduced to about 10 ⁻⁴ Pa. And a layer containing molybdenum oxide were formed. At this time, co-evaporation was performed so that the ratio of t-BuDNA to molybdenum oxide was 2: 1 by weight. The film thickness was 100 nm.

(Sample 4)
Similar to sample 3, the quartz substrate is fixed to the substrate holder in the vacuum deposition apparatus. Then, DPPA and molybdenum oxide (VI) are put in separate resistance heating evaporation sources, then the inside of the vacuum apparatus is evacuated, and the pressure is reduced to about 10 ⁻⁴ Pa. A layer containing was formed. At this time, co-evaporation was performed such that the ratio of DPPA to molybdenum oxide was 2: 1 by weight. The film thickness was 100 nm.

(Sample 5)
Similar to sample 3, the quartz substrate is fixed to the substrate holder in the vacuum deposition apparatus. Then, DNA and molybdenum oxide (VI) are put in separate resistance heating type evaporation sources, then the inside of the vacuum apparatus is evacuated, and the pressure is reduced to about 10 ⁻⁴ Pa. A layer containing was formed. At this time, co-evaporation was performed so that the ratio of DNA to molybdenum oxide was 2: 1 by weight. The film thickness was 100 nm.

(Sample 6)
Similar to sample 3, the quartz substrate is fixed to the substrate holder in the vacuum deposition apparatus. Then, DPAnth and molybdenum oxide (VI) are put in separate resistance heating type evaporation sources, then the inside of the vacuum apparatus is evacuated, and the pressure is reduced to about 10 ⁻⁴ Pa. Then, DPAnth and molybdenum oxide are A layer containing was formed. At this time, co-evaporation was performed so that the ratio of DPAnth to molybdenum oxide was 2: 1 by weight. The film thickness was 100 nm.

The t-BuDNA-molybdenum oxide composite layer (sample 3), DPPA-molybdenum oxide composite layer (sample 4), DNA-molybdenum oxide composite layer (sample 5), DPAnth-molybdenum oxide composite layer ( FIG. 38 shows the result of measuring the absorption spectrum of Sample 6) in the wavelength region of 450 nm to 800 nm. The transmittance is shown in FIG.

  As can be seen from FIGS. 5 and 38, t-BuDNA-molybdenum oxide composite layer (sample 3), DPPA-molybdenum oxide composite layer (sample 4), DNA-molybdenum oxide composite layer (sample 5), DPAnth-molybdenum oxide composite All the layers (sample 6) do not show an absorption peak in the wavelength region of 450 nm to 800 nm and have a transmittance of 80% or more.

  Therefore, it can be seen that the composite material of the present invention and the organic compound layer provided in contact with the composite material do not have an absorption peak in the wavelength region of 450 nm to 800 nm and have high transmittance.

In addition, the organic compound layer has a higher transmittance than the layer including the composite material. Therefore, it can be seen that a stacked body of a layer including a composite material and an organic compound layer provided in contact with the composite material has a transmittance of greater than 80%.

また、透過率は式（１２）で表される。

よって、式（１２）を式（１１）に代入することにより、吸光度は式（１３）で表される。

例えば、膜厚Ｌ＝１００ｎｍのとき、透過率Ｔ＝８０％の場合、単位膜厚当たりの吸光係数は、式（１４）で表される。

本発明の発光素子に用いる複合材料は、４５０ｎｍ〜８００ｎｍの波長領域において透過率が８０％以上であることが好ましい。つまり、式（１５）の関係を満たすことが好ましい。

なお、反射材料など、透過光が０の場合には、ランバート・ベールの法則が成立しないため、式（１５）には該当しない。 Further, according to Lambert-Beer's law, the relationship between the absorbance and the film thickness is expressed by Expression (11).

Further, the transmittance is expressed by Expression (12).

Therefore, by substituting equation (12) into equation (11), the absorbance is expressed by equation (13).

For example, when the film thickness L = 100 nm and the transmittance T = 80%, the extinction coefficient per unit film thickness is expressed by Expression (14).

The composite material used for the light-emitting element of the present invention preferably has a transmittance of 80% or more in a wavelength region of 450 nm to 800 nm. That is, it is preferable to satisfy the relationship of Formula (15).

Note that when the transmitted light is 0, such as a reflective material, Lambert-Beer's law does not hold, and therefore does not correspond to the equation (15).

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted so as to contain 10 vol% molybdenum oxide by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDNA was formed to a thickness of 10 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material. The ionization potential value of t-BuDNA was 5.55 eV.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDNA by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 1 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a film thickness of 200 nm using a vapor deposition method using resistance heating.

(Comparative Example 2)
First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted so as to contain 10 vol% molybdenum oxide by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, NPB was formed to a thickness of 10 nm by an evaporation method using resistance heating.

  Further, a light emitting layer having a thickness of 40 nm was formed on NPB by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a comparative light-emitting element 1 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a film thickness of 200 nm by using a resistance heating vapor deposition method.

  FIG. 6 shows current-voltage characteristics of the light-emitting element 1 manufactured in Example 3 and the comparative light-emitting element 1 manufactured in Comparative Example 2. Further, FIG. 7 shows luminance-voltage characteristics. Further, FIG. 8 shows current efficiency-luminance characteristics.

In the light-emitting element 1, a voltage necessary to obtain a luminance of 1226 cd / m ² was 5.6 V, and a current flowing at that time was 0.35 mA (current density was 8.63 mA / cm ² ). Moreover, the current efficiency at this time was 14.2 cd / A. On the other hand, in the comparative light-emitting element 1, the voltage necessary to obtain a luminance of 1096 cd / m ² is 5.8 V, and the current flowing at that time is 0.34 mA (current density is 8.57 mA / cm ² ). It was. Moreover, the current efficiency at this time was 12.8 cd / A.

  The light-emitting element 1 has almost the same current-voltage characteristics as the comparative light-emitting element 1. However, it can be seen that the luminance-voltage characteristics are also improved by improving the current efficiency-luminance characteristics. That is, it can be seen that the voltage required to obtain a constant luminance has been reduced.

  From the above results, it was found that the light emission efficiency is improved by applying the present invention.

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted so as to contain 10 vol% molybdenum oxide by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDNA was formed to a thickness of 10 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material. The ionization potential value of t-BuDNA was 5.55 eV.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDNA by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Thereafter, BPhen was deposited to a thickness of 30 nm on the light-emitting layer using a resistance heating vapor deposition method to form an electron transport layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 2 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm using an evaporation method using resistance heating.

(Comparative Example 3)
First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted so as to contain 10 vol% molybdenum oxide by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, NPB was formed to a thickness of 10 nm by an evaporation method using resistance heating.

  Further, a light emitting layer having a thickness of 40 nm was formed on NPB by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Thereafter, BPhen was deposited to a thickness of 30 nm on the light-emitting layer using a resistance heating vapor deposition method to form an electron transport layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a comparative light-emitting element 2 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

  FIG. 9 shows current-voltage characteristics of the light-emitting element 2 manufactured in Example 4 and the comparative light-emitting element 2 manufactured in Comparative Example 3. Further, FIG. 10 shows luminance-voltage characteristics. Further, FIG. 11 shows current efficiency-luminance characteristics.

In the light-emitting element 2, a voltage necessary for obtaining a luminance of 1233 cd / m ² was 4.6 V, and a current flowing at that time was 0.36 mA (current density was 8.90 mA / cm ² ). Moreover, the current efficiency at this time was 13.9 cd / A. On the other hand, in the comparative light-emitting element 2, the voltage necessary to obtain a luminance of 1179 cd / m ² is 4.8 V, and the current flowing at that time is 0.38 mA (current density is 9.59 mA / cm ² ). It was. Moreover, the current efficiency at this time was 12.3 cd / A.

  The light-emitting element 2 has almost the same current-voltage characteristics as the comparative light-emitting element 2. However, it can be seen that the luminance-voltage characteristics are also improved by improving the current efficiency-luminance characteristics. That is, it can be seen that the voltage required to obtain a constant luminance has been reduced.

  From the above results, it was found that the light emission efficiency is improved by applying the present invention.

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted so as to contain 10 vol% molybdenum oxide by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDBA was formed to a thickness of 10 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDBA by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 3 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

(Comparative Example 4)
First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted so as to contain 10 vol% molybdenum oxide by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, NPB was formed to a thickness of 10 nm by an evaporation method using resistance heating.

  Further, a light emitting layer having a thickness of 40 nm was formed on NPB by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a comparative light-emitting element 3 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

  FIG. 12 shows current-voltage characteristics of the light-emitting element 3 manufactured in Example 5 and the comparative light-emitting element 3 manufactured in Comparative Example 4. Further, FIG. 13 shows luminance-voltage characteristics. Further, FIG. 14 shows current efficiency-luminance characteristics.

In the light-emitting element 3, a voltage necessary to obtain a luminance of 1063 cd / m ² was 5.6 V, and a current flowing at that time was 0.31 mA (current density was 7.65 mA / cm ² ). Moreover, the current efficiency at this time was 13.9 cd / A. On the other hand, in the comparative light-emitting element 3, the voltage necessary for obtaining a luminance of 1027 cd / m ² is 5.8 V, and the current flowing at that time is 0.32 mA (current density is 8.11 mA / cm ² ). It was. The current efficiency at this time was 12.7 cd / A.

  The light-emitting element 3 has substantially the same current-voltage characteristics as the comparative light-emitting element 3. However, it can be seen that the luminance-voltage characteristics are also improved by improving the current efficiency-luminance characteristics. That is, it can be seen that the voltage required to obtain a constant luminance has been reduced.

  From the above results, it was found that the light emission efficiency is improved by applying the present invention.

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. After that, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDBA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDBA to molybdenum oxide (VI) was adjusted so that 10 vol% of molybdenum oxide was contained by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDBA was formed to a thickness of 10 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDBA by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 4 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

(Comparative Example 5)
First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. After that, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDBA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDBA to molybdenum oxide (VI) was adjusted so that 10 vol% of molybdenum oxide was contained by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, NPB was formed to a thickness of 10 nm by an evaporation method using resistance heating.

  Further, a light emitting layer having a thickness of 40 nm was formed on NPB by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a comparative light-emitting element 4 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a film thickness of 200 nm by using a resistance heating vapor deposition method.

  FIG. 15 shows current-voltage characteristics of the light-emitting element 4 manufactured in Example 6 and the comparative light-emitting element 4 manufactured in Comparative Example 5. In addition, FIG. 16 shows luminance-voltage characteristics. Further, FIG. 17 shows current efficiency-luminance characteristics.

In the light-emitting element 4, a voltage necessary to obtain a luminance of 1105 cd / m ² was 5.6 V, and a current flowing at that time was 0.31 mA (current density was 7.86 mA / cm ² ). Moreover, the current efficiency at this time was 14.1 cd / A. On the other hand, in the comparative light-emitting element 4, the voltage necessary to obtain a luminance of 1010 cd / m ² is 5.8 V, and the current flowing at that time is 0.31 mA (current density is 7.87 mA / cm ² ). It was. Moreover, the current efficiency at this time was 12.8 cd / A.

  The light-emitting element 4 has substantially the same current-voltage characteristics as the comparative light-emitting element 4. However, it can be seen that the luminance-voltage characteristics are also improved by improving the current efficiency-luminance characteristics. That is, it can be seen that the voltage required to obtain a constant luminance has been reduced.

  From the above results, it was found that the light emission efficiency is improved by applying the present invention.

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted to 4: 1 (= t-BuDNA: molybdenum oxide) by weight. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDNA was formed to a thickness of 10 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material. The ionization potential value of t-BuDNA was 5.55 eV.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDNA by co-evaporating Alq and coumarin 6. Here, the weight ratio of Alq to coumarin 6 was adjusted to be 4: 0.04 (= Alq: coumarin 6). As a result, the coumarin 6 is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 5 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted to 4: 1 (= t-BuDNA: molybdenum oxide) by weight. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber. The ionization potential value of t-BuDNA was 5.55 eV.

  Next, DPPA was formed to a thickness of 10 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material. The value of the ionization potential of DPPA was 5.83 eV.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on DPPA by co-evaporating Alq and coumarin 6. Here, the weight ratio of Alq to coumarin 6 was adjusted to be 4: 0.04 (= Alq: coumarin 6). As a result, the coumarin 6 is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 6 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a film thickness of 200 nm by using a resistance heating vapor deposition method.

(Comparative Example 6)
First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted to 4: 1 (= t-BuDNA: molybdenum oxide) by weight. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, NPB was formed to a thickness of 10 nm by an evaporation method using resistance heating.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on NPB by co-evaporating Alq and coumarin 6. Here, the weight ratio of Alq to coumarin 6 was adjusted to be 4: 0.04 (= Alq: coumarin 6). As a result, the coumarin 6 is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a comparative light-emitting element 5 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a film thickness of 200 nm using a vapor deposition method using resistance heating.

(Comparative Example 7)
First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted to 4: 1 (= t-BuDNA: molybdenum oxide) by weight. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, 4,4′-bis [N-phenyl-N- (spirofluoren-2-yl)] biphenyl (abbreviation: BSPB) is formed to a thickness of 10 nm by an evaporation method using resistance heating. Filmed.

  Further, a light emitting layer having a thickness of 40 nm was formed on BSPB by co-evaporating Alq and coumarin 6. Here, the weight ratio of Alq to coumarin 6 was adjusted to be 4: 0.04 (= Alq: coumarin 6). As a result, the coumarin 6 is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a comparative light-emitting element 6 was fabricated by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

  FIG. 18 shows current-voltage characteristics of the light-emitting element 5 manufactured in Example 7, the light-emitting element 6 manufactured in Example 8, the comparative light-emitting element 5 manufactured in Comparative Example 6, and the comparative light-emitting element 6 manufactured in Comparative Example 7. Show. In addition, FIG. 19 shows luminance-voltage characteristics. Further, FIG. 20 shows current efficiency-luminance characteristics.

In the light-emitting element 5, a voltage necessary for obtaining a luminance of 1202 cd / m ² was 5.8 V, and a current flowing at that time was 0.36 mA (current density was 9.00 mA / cm ² ). Moreover, the current efficiency at this time was 13.4 cd / A. In the light-emitting element 6, a voltage necessary for obtaining a luminance of 1057 cd / m ² was 6.0 V, and a current flowing at that time was 0.35 mA (current density was 8.72 mA / cm ² ). The current efficiency at this time was 12.1 cd / A. On the other hand, in the comparative light-emitting element 5, the voltage necessary for obtaining a luminance of 1103 cd / m ² is 6.0 V, and the current flowing at that time is 0.46 mA (current density is 11.54 mA / cm ² ). It was. Moreover, the current efficiency at this time was 9.6 cd / A. In Comparative Light-Emitting Element 6, the voltage required to obtain a luminance of 1159 cd / m ² was 5.8 V, and the current flowing at that time was 0.473 mA (current density was 11.74 mA / cm ² ). The current efficiency at this time was 9.9 cd / A.

  The light-emitting element 5 and the light-emitting element 6 have substantially the same current-voltage characteristics as compared with the comparative light-emitting element 5 and the comparative light-emitting element 6. However, it can be seen that the light-emitting element 5 and the light-emitting element 6 have improved luminance-voltage characteristics due to the improved current efficiency-luminance characteristics compared to the comparative light-emitting elements 5 and 6. That is, it can be seen that the voltage required to obtain a constant luminance has been reduced.

  From the above results, it was found that the driving voltage of the light emitting element can be reduced by applying the present invention. Moreover, it turned out that luminous efficiency improves.

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, DNTPD and molybdenum oxide (VI) were co-evaporated on the first electrode, thereby forming a layer containing the composite material. The film thickness was 120 nm, and the weight ratio of DNTPD to molybdenum oxide (VI) was adjusted to 1: 0.67 (= DNTPD: molybdenum oxide). Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, DNTPD was formed to a thickness of 5 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material.

  Further, NPB was deposited on DNTPD to a thickness of 5 nm by a vapor deposition method using resistance heating.

  Next, Alq and coumarin 6 were co-evaporated to form a light-emitting layer having a thickness of 40 nm on NPB. Here, the weight ratio of Alq to coumarin 6 was adjusted to be 1: 0.005 (= Alq: coumarin 6). As a result, the coumarin 6 is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 7 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

(Comparative Example 8)
First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, DNTPD and molybdenum oxide (VI) were co-evaporated on the first electrode, thereby forming a layer containing the composite material. The film thickness was 120 nm, and the weight ratio of DNTPD to molybdenum oxide (VI) was adjusted to 1: 0.67 (= DNTPD: molybdenum oxide). Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, NPB was formed to a thickness of 10 nm by an evaporation method using resistance heating.

  Next, Alq and coumarin 6 were co-evaporated to form a light-emitting layer having a thickness of 40 nm on NPB. Here, the weight ratio of Alq to coumarin 6 was adjusted to be 1: 0.005 (= Alq: coumarin 6). As a result, the coumarin 6 is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a comparative light-emitting element 7 was fabricated by forming a second electrode by depositing aluminum on the electron injection layer so as to have a film thickness of 200 nm using an evaporation method using resistance heating.

  FIG. 21 shows current-voltage characteristics of the light-emitting element 7 manufactured in Example 9 and the comparative light-emitting element 7 manufactured in Comparative Example 8. Further, FIG. 22 shows luminance-voltage characteristics. Further, FIG. 23 shows current efficiency-luminance characteristics.

In the light-emitting element 7, a voltage necessary to obtain a luminance of 1287 cd / m ² was 5.6 V, and a current flowing at that time was 0.46 mA (current density was 11.59 mA / cm ² ). Moreover, the current efficiency at this time was 11.1 cd / A. On the other hand, in the comparative light-emitting element 7, the voltage required to obtain a luminance of 1094 cd / m ² is 5.8 V, and the current flowing at that time is 0.47 mA (current density is 11.74 mA / cm ² ). It was. Moreover, the current efficiency at this time was 9.3 cd / A.

  The light-emitting element 7 has substantially the same current-voltage characteristics as the comparative light-emitting element 7. However, it can be seen that the luminance-voltage characteristics are also improved by improving the current efficiency-luminance characteristics. That is, it can be seen that the voltage required to obtain a constant luminance has been reduced.

  From the above results, it was found that the light emission efficiency is improved by applying the present invention.

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 20 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted so as to contain 10 vol% molybdenum oxide by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDNA was formed to a thickness of 10 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDNA by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 8 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

(Comparative Example 9)
First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, NPB and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. The film thickness was 20 nm, and the ratio between NPB and molybdenum oxide (VI) was adjusted so that 10 vol% of molybdenum oxide was contained by volume ratio. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDNA was formed to a thickness of 10 nm by an evaporation method using resistance heating.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDNA by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a comparative light-emitting element 8 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

  FIG. 24 shows current-voltage characteristics of the light-emitting element 8 manufactured in Example 10 and the comparative light-emitting element 8 manufactured in Comparative Example 9. In addition, FIG. 25 shows luminance-voltage characteristics. In addition, FIG. 26 shows current efficiency-luminance characteristics.

In the light-emitting element 8, a voltage necessary for obtaining a luminance of 1130 cd / m ² was 5.4 V, and a current flowing at that time was 0.27 mA (current density was 6.76 mA / cm ² ). The current efficiency at this time was 16.7 cd / A. On the other hand, in the comparative light-emitting element 8, the voltage necessary to obtain a luminance of 1180 cd / m ² is 7.4 V, and the current flowing at that time is 0.37 mA (current density is 9.16 mA / cm ² ). It was. The current efficiency at this time was 12.9 cd / A.

  The light emitting element 8 has improved current-voltage characteristics compared to the comparative light emitting element 8. That is, it can be seen that the current easily flows. In addition, the light emitting element 8 has improved current efficiency-luminance characteristics compared to the comparative light emitting element 8. It can also be seen that the luminance-voltage characteristics are also improved. That is, it can be seen that the voltage required to obtain a constant luminance has been reduced.

The comparative light-emitting element 8 uses NPB as the organic compound contained in the layer containing the composite material, and the aromatic hydrocarbon having a large ionization potential is used as the layer containing the organic compound provided in contact with the layer containing the composite material. T-BuDNA is used. In the comparative light-emitting element 8, the driving voltage is high because the carrier injection barrier from the layer containing the composite material to the layer containing the organic compound provided so as to be in contact with the layer containing the composite material is large. In addition, since the layer including the composite material of the comparative light-emitting element 8 has an absorption peak in the wavelength region of 450 nm to 800 nm, part of light emitted from the light emitting region is absorbed.

  On the other hand, the light-emitting element 8 uses t-BuDNA, which is an aromatic hydrocarbon having a large ionization potential, as the first organic compound contained in the composite material. Therefore, t-BuDNA, which is an aromatic hydrocarbon having a high ionization potential, can be used as the layer containing the second organic compound provided in contact with the layer containing the composite material. In addition, since the same organic compound is used for the layer including the composite material and the layer provided so as to be in contact with the layer including the composite material, a carrier injection barrier is small. Therefore, the driving voltage of the light emitting element can be reduced. In addition, since the layer including the composite material of the light-emitting element 8 does not have an absorption peak in the wavelength region of 450 nm to 800 nm, light emitted from the light-emitting region can be efficiently extracted outside. Therefore, light emission efficiency can be improved.

  From the above results, the light emitting element can be driven at a low voltage by applying the present invention. In addition, luminous efficiency can be improved.

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted so as to contain 10 vol% molybdenum oxide by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDNA was formed to a thickness of 10 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDNA by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 9 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

(Comparative Example 10)
First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, NPB and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. The film thickness was 50 nm, and the ratio of NPB to molybdenum oxide (VI) was adjusted so that 10 vol% of molybdenum oxide was contained by volume ratio. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDNA was formed to a thickness of 10 nm by an evaporation method using resistance heating.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDNA by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a comparative light emitting element 9 was fabricated by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm by using a resistance heating vapor deposition method.

  FIG. 27 shows current-voltage characteristics of the light-emitting element 9 manufactured in Example 11 and the comparative light-emitting element 9 manufactured in Comparative Example 10. In addition, FIG. 28 shows luminance-voltage characteristics. FIG. 29 shows current efficiency-luminance characteristics.

In the light-emitting element 9, a voltage necessary to obtain a luminance of 1009 cd / m ² was 5.6 V, and a current flowing at that time was 0.30 mA (current density was 7.46 mA / cm ² ). Moreover, the current efficiency at this time was 13.5 cd / A. On the other hand, in the comparative light-emitting element 9, the voltage necessary to obtain a luminance of 1295 cd / m ² is 7.8 V, and the current that flows at that time is 0.50 mA (current density is 12.62 mA / cm ² ). It was. Moreover, the current efficiency at this time was 10.3 cd / A.

  The light emitting element 9 has improved current-voltage characteristics compared to the comparative light emitting element 9. That is, it can be seen that the current easily flows. In addition, the light emitting element 9 has improved current efficiency-luminance characteristics compared to the comparative light emitting element 9. It can also be seen that the luminance-voltage characteristics are also improved. That is, it can be seen that the voltage required to obtain a constant luminance has been reduced.

The comparative light-emitting element 9 uses NPB as the organic compound contained in the layer containing the composite material, and the aromatic hydrocarbon having a high ionization potential is used as the layer containing the organic compound provided in contact with the layer containing the composite material. T-BuDNA is used. In the comparative light-emitting element 9, the driving voltage is high because the carrier injection barrier from the layer including the composite material to the layer including the organic compound provided so as to be in contact with the layer including the composite material is large. In addition, since the layer including the composite material of the comparative light-emitting element 9 has an absorption peak in the wavelength region of 450 nm to 800 nm, part of light emitted from the light emitting region is absorbed.

  On the other hand, the light-emitting element 9 uses t-BuDNA, which is an aromatic hydrocarbon having a large ionization potential, as the first organic compound contained in the composite material. Therefore, t-BuDNA, which is an aromatic hydrocarbon having a high ionization potential, can be used as the layer containing the second organic compound provided in contact with the layer containing the composite material. In addition, since the same organic compound is used for the layer including the composite material and the layer provided so as to be in contact with the layer including the composite material, a carrier injection barrier is small. Therefore, the driving voltage of the light emitting element can be reduced. In addition, since the layer including the composite material of the light-emitting element 9 does not have an absorption peak in the wavelength region of 450 nm to 800 nm, light emitted from the light-emitting region can be efficiently extracted outside. Therefore, light emission efficiency can be improved.

  From the above results, the light emitting element can be driven at a low voltage by applying the present invention. In addition, luminous efficiency can be improved.

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 150 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted so as to contain 10 vol% molybdenum oxide by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDNA was formed to a thickness of 10 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDNA by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 10 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm using an evaporation method using resistance heating.

(Comparative Example 11)
First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, NPB and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. The film thickness was 150 nm, and the ratio between NPB and molybdenum oxide (VI) was adjusted so that 10 vol% molybdenum oxide was contained by volume. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDNA was formed to a thickness of 10 nm by an evaporation method using resistance heating.

  Furthermore, a light emitting layer having a thickness of 40 nm was formed on t-BuDNA by co-evaporating Alq and DPQd. Here, the weight ratio of Alq to DPQd was adjusted to be 1: 0.005 (= Alq: DPQd). As a result, DPQd is dispersed in the Alq layer.

  Then, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a thickness of 30 nm to form an electron transporting layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a comparative light-emitting element 10 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a thickness of 200 nm using an evaporation method using resistance heating.

  FIG. 30 shows current-voltage characteristics of the light-emitting element 10 manufactured in Example 12 and the comparative light-emitting element 10 manufactured in Comparative Example 11. Further, FIG. 31 shows luminance-voltage characteristics. Further, FIG. 32 shows current efficiency-luminance characteristics.

In the light-emitting element 10, a voltage necessary to obtain a luminance of 1087 cd / m ² was 5.4 V, and a current flowing at that time was 0.30 mA (current density was 7.51 mA / cm ² ). The current efficiency at this time was 14.5 cd / A. On the other hand, in the comparative light-emitting element 1, the voltage necessary to obtain the luminance of 1272 cd / m ² is 7.6 V, and the current flowing at that time is 0.45 mA (current density is 11.17 mA / cm ² ). It was. Moreover, the current efficiency at this time was 11.4 cd / A.

  The light emitting element 10 has improved current-voltage characteristics compared to the comparative light emitting element 10. That is, it can be seen that the current easily flows. In addition, the light emitting element 10 has improved current efficiency-luminance characteristics as compared with the comparative light emitting element 10. It can also be seen that the luminance-voltage characteristics are also improved. That is, it can be seen that the voltage required to obtain a constant luminance has been reduced.

The comparative light-emitting element 10 uses NPB as an organic compound contained in the layer containing the composite material, and an aromatic hydrocarbon having a large ionization potential as the layer containing the organic compound provided in contact with the layer containing the composite material T-BuDNA is used. In the comparative light-emitting element 10, the driving voltage is high because the carrier injection barrier from the layer including the composite material to the layer including the organic compound provided so as to be in contact with the layer including the composite material is large. In addition, since the layer including the composite material of the comparative light-emitting element 10 has an absorption peak in a wavelength region of 450 nm to 800 nm, part of light emitted from the light emitting region is absorbed.

  On the other hand, the light-emitting element 10 uses t-BuDNA, which is an aromatic hydrocarbon having a large ionization potential, as the first organic compound contained in the composite material. Therefore, t-BuDNA, which is an aromatic hydrocarbon having a high ionization potential, can be used as the layer containing the second organic compound provided in contact with the layer containing the composite material. In addition, since the same organic compound is used for the layer including the composite material and the layer provided so as to be in contact with the layer including the composite material, a carrier injection barrier is small. Therefore, the driving voltage of the light emitting element can be reduced. In addition, since the layer including the composite material of the light-emitting element 10 does not have an absorption peak in the wavelength region of 450 nm to 800 nm, light emitted from the light-emitting region can be efficiently extracted outside. Therefore, light emission efficiency can be improved.

  From the above results, the light emitting element can be driven at a low voltage by applying the present invention. In addition, luminous efficiency can be improved.

  In this example, the light-emitting element of the present invention will be described more specifically.

  First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, the inside of the vacuum apparatus was evacuated, and the pressure was reduced to about 10 ⁻⁴ Pa. Then, t-BuDNA and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer containing the composite material. . The film thickness was 50 nm, and the ratio of t-BuDNA to molybdenum oxide (VI) was adjusted to 4: 1 (= t-BuDNA: molybdenum oxide) by weight. Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

  Next, t-BuDNA was formed to a thickness of 10 nm by an evaporation method using resistance heating so as to be in contact with the layer containing the composite material.

  Further, 9- [4- (N-carbazolyl)] phenyl-10-phenylanthracene (abbreviation: CzPA) and 9- (4- {N- [4- (9-carbazolyl) phenyl] -N-phenylamino} phenyl ) -10-phenylanthracene (abbreviation: YGAPA) was co-evaporated to form a light-emitting layer having a thickness of 30 nm on t-BuDNA. Here, the weight ratio of CzPA to YGAPA was adjusted to be 4: 0.16 (= CzPA: YGAPA).

  Thereafter, an evaporation method using resistance heating was used to form a film of BPhen with a thickness of 5 nm and Alq with a thickness of 30 nm on the light emitting layer, thereby forming an electron transport layer.

  Further, on the electron transport layer, lithium fluoride was deposited to a thickness of 1 nm by a resistance heating vapor deposition method to form an electron injection layer.

  Finally, a light emitting element 11 was manufactured by forming a second electrode by depositing aluminum on the electron injection layer so as to have a film thickness of 200 nm by using a resistance heating vapor deposition method.

  FIG. 39 shows current-voltage characteristics of the light-emitting element 11 manufactured in Example 13. In addition, FIG. 40 shows luminance-voltage characteristics. Further, FIG. 41 shows current efficiency-luminance characteristics.

In the light-emitting element 11, a voltage necessary for obtaining a luminance of 1023 cd / m ² was 10.6 V, and a current flowing at that time was 2.46 mA (current density was 61.5 mA / cm ² ). In addition, current efficiency at this time was 1.66 cd / A, CIE chromaticity coordinates were (x, y = 0.16, 0.13), and blue light emission was obtained.

  The light emitting element 11 uses t-BuDNA, which is an aromatic hydrocarbon having a large ionization potential, as the first organic compound contained in the composite material. Therefore, t-BuDNA, which is an aromatic hydrocarbon having a high ionization potential, can be used as the layer containing the second organic compound provided in contact with the layer containing the composite material. In addition, since the same organic compound is used for the layer including the composite material and the layer provided so as to be in contact with the layer including the composite material, a carrier injection barrier is small. Therefore, the driving voltage of the light emitting element can be reduced. In addition, since the layer including the composite material of the light-emitting element 11 does not have an absorption peak in the wavelength region of 450 nm to 800 nm, light emitted from the light-emitting region can be efficiently extracted outside. Therefore, light emission efficiency can be improved.

  From the above results, the light emitting element can be driven at a low voltage by applying the present invention. In addition, luminous efficiency can be improved.

4A and 4B illustrate a light-emitting element of the present invention. 4A and 4B illustrate a light-emitting element of the present invention. 4A and 4B illustrate a light-emitting element of the present invention. The figure which shows the transmittance | permeability of a composite material. The figure which shows the transmittance | permeability of a composite material. FIG. 11 shows current-voltage characteristics of a light-emitting element. FIG. 11 shows luminance-voltage characteristics of a light-emitting element. FIG. 11 shows current efficiency-luminance characteristics of a light-emitting element. FIG. 11 shows current-voltage characteristics of a light-emitting element. FIG. 11 shows luminance-voltage characteristics of a light-emitting element. FIG. 11 shows current efficiency-luminance characteristics of a light-emitting element. FIG. 11 shows current-voltage characteristics of a light-emitting element. FIG. 11 shows luminance-voltage characteristics of a light-emitting element. FIG. 11 shows current efficiency-luminance characteristics of a light-emitting element. FIG. 11 shows current-voltage characteristics of a light-emitting element. FIG. 11 shows luminance-voltage characteristics of a light-emitting element. FIG. 11 shows current efficiency-luminance characteristics of a light-emitting element. FIG. 11 shows current-voltage characteristics of a light-emitting element. FIG. 11 shows luminance-voltage characteristics of a light-emitting element. FIG. 11 shows current efficiency-luminance characteristics of a light-emitting element. FIG. 11 shows current-voltage characteristics of a light-emitting element. FIG. 11 shows luminance-voltage characteristics of a light-emitting element. FIG. 11 shows current efficiency-luminance characteristics of a light-emitting element. FIG. 11 shows current-voltage characteristics of a light-emitting element. FIG. 11 shows luminance-voltage characteristics of a light-emitting element. FIG. 11 shows current efficiency-luminance characteristics of a light-emitting element. FIG. 11 shows current-voltage characteristics of a light-emitting element. FIG. 11 shows luminance-voltage characteristics of a light-emitting element. FIG. 11 shows current efficiency-luminance characteristics of a light-emitting element. FIG. 11 shows current-voltage characteristics of a light-emitting element. FIG. 11 shows luminance-voltage characteristics of a light-emitting element. FIG. 11 shows current efficiency-luminance characteristics of a light-emitting element. 4A and 4B illustrate a light-emitting device of the present invention. 4A and 4B illustrate a light-emitting device of the present invention. 8A and 8B each illustrate an electronic device of the invention. 8A and 8B each illustrate an electronic device of the invention. The figure which shows the absorption spectrum of a composite material. The figure which shows the absorption spectrum of a composite material. FIG. 11 shows current-voltage characteristics of a light-emitting element. FIG. 11 shows luminance-voltage characteristics of a light-emitting element. FIG. 11 shows current efficiency-luminance characteristics of a light-emitting element.

Explanation of symbols

101 Substrate 102 1st electrode 103 1st layer 104 2nd layer 105 3rd layer 106 4th layer 107 2nd electrode 108 Layer 302 containing the substance with a high hole-transport property 302 1st electrode 303 1st 1 layer 304 2nd layer 305 3rd layer 306 4th layer 307 2nd electrode 601 Source side driving circuit 602 Pixel portion 603 Gate side driving circuit 604 Sealing substrate 605 Sealing material 607 Space 608 Wiring 609 FPC ( Flexible printed circuit)
610 Element substrate 611 TFT for switching
612 Current control TFT
613 First electrode 614 Insulator 616 Layer containing light emitting substance 617 Second electrode 618 Light emitting element 623 n-channel TFT
624 p-channel TFT
901 Case 902 Liquid crystal layer 903 Backlight 904 Case 905 Driver IC
906 Terminal 951 Substrate 952 Electrode 953 Insulating layer 954 Partition layer 955 Layer 995 containing luminescent material Electrode 9101 Housing 9102 Support base 9103 Display portion 9104 Speaker portion 9105 Video input terminal 9201 Body 9202 Housing 9203 Display portion 9204 Keyboard 9205 External connection port 9206 Pointing mouse 9401 Main body 9402 Case 9403 Display unit 9404 Audio input unit 9405 Audio output unit 9405 Operation key 9407 External connection port 9408 Antenna 9501 Main unit 9502 Display unit 9503 Case 9504 External connection port 9505 Remote control receiving unit 9506 Image receiving unit 9507 Battery 9508 Voice input unit 9509 Operation key 9510 Eyepiece unit

Claims (10)

Between a pair of electrodes,
A layer containing a composite material formed by combining a first organic compound and an inorganic compound;
A layer containing a second organic compound in contact with the layer containing the composite material;
A laminated body in which
A layer containing a luminescent material;
Have
The first organic compound is an aromatic hydrocarbon, not used in combination with an aromatic organic amine compound,
The light-emitting element, wherein the composite material does not have an absorption spectrum peak in a wavelength region of 450 nm to 800 nm. In claim 1,
The light-emitting element, wherein the composite material does not have an absorption spectrum peak in a wavelength region of 450 nm to 800 nm and has a transmittance of 80% or more per 100 nm thickness. In claim 1 or claim 2,
The light-emitting element, wherein the first organic compound is an anthracene derivative. In any one of Claims 1 to 2,
The light-emitting element, wherein the inorganic compound exhibits an electron accepting property with respect to the first organic compound. In any one of Claims 1 thru | or 4,
The light-emitting element, wherein the inorganic compound is a transition metal oxide. In any one of Claims 1 thru | or 4,
The light-emitting element, wherein the inorganic compound is any one of vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. In any one of Claims 1 thru | or 4,
The light-emitting element, wherein the inorganic compound is molybdenum oxide. A light emitting device comprising the light emitting element according to claim 1. An illuminating device comprising the light emitting element according to any one of claims 1 to 7. The electronic device which used the light emitting element as described in any one of Claim 1 thru | or 7 for the display part.

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