JP5089063B2 - COMPOSITE MATERIAL, LIGHT EMITTING ELEMENT AND LIGHT EMITTING DEVICE USING COMPOSITE MATERIAL - Google Patents

Description

The present invention relates to a composite material in which an organic compound and an inorganic compound are combined, which is excellent in carrier transportability, carrier injection property into an organic compound, and in visible light transmittance. The present invention also relates to a current excitation type light emitting element using the composite material. Further, the present invention relates to a light emitting device 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.

  As described above, a current-excitation light-emitting element using a light-emitting organic compound is expected to be applied to a light-emitting device, illumination, and the like, but there are still many problems. One of the problems is reduction of power consumption. In order to reduce power consumption, it is important to reduce the driving voltage of the light emitting element. In the current excitation type light emitting element, since the light emission intensity is determined by the amount of flowing current, it is necessary to flow a large amount of current at a low voltage in order to reduce the driving voltage.

  Until now, as a method for reducing the drive voltage, an attempt has been made to provide a buffer layer between an electrode and a layer containing a light-emitting organic compound. For example, it is known that a driving voltage can be reduced by providing a buffer layer made of polyaniline (PANI) doped with camphorsulfonic acid between indium tin oxide (ITO) and a light emitting layer (for example, non-patent Reference 1). This is explained because the carrier injection property to the light emitting layer of PANI is excellent. In Non-Patent Document 1, PANI, which is a buffer layer, is also regarded as a part of the electrode.

  However, as described in Non-Patent Document 1, PANI has a problem that transmittance increases when the film thickness is increased. Specifically, it is reported that the transmittance is less than 70% at a film thickness of about 250 nm. That is, there is a problem with the transparency of the material itself used for the buffer layer, and thus light generated inside the element cannot be extracted efficiently.

Further, according to Patent Document 1, an attempt is made to increase luminance per certain current density, that is, current efficiency by connecting light emitting elements (described as light emitting units in Patent Document 1) in series. Yes. In Patent Document 1, a layer in which an organic compound and a metal oxide (specifically, vanadium oxide and rhenium oxide) are mixed is applied to a connection portion when the light emitting elements are connected in series. It is said that holes and electrons can be injected into the light emitting unit.

However, the mixed layer of the organic compound and the metal oxide disclosed in Patent Document 1 has a large absorption peak not only in the infrared region but also in the visible light region (around 500 nm) as can be seen from the examples. It has occurred and there is still a problem with transparency. Therefore, the light generated inside the device cannot be extracted efficiently, and the light emission efficiency of the device is lowered.

Y. Yang, 1 other person, Applied Physics Letters, Vol. 64 (10), 1245-1247 (1994) JP 2003-272860 A

  Therefore, the present invention provides a composite material in which an organic compound and an inorganic compound are combined, and is excellent in carrier transportability and carrier injection property into the organic compound, and also has excellent visible light transmittance. Let it be an issue.

  It is another object of the present invention to provide a light-emitting element with a low driving voltage by applying the composite material to a current-excitation light-emitting element. Another object is to provide a light-emitting device with low power consumption by manufacturing a light-emitting device using the light-emitting element.

  As a result of extensive studies, the present inventor has found that the problem can be solved by using a layer containing an organic compound and an inorganic compound that can exchange electrons with the organic compound.

  That is, the composite material of the present invention includes a carbazole derivative represented by the general formula (1) and an inorganic compound exhibiting an electron accepting property with respect to the carbazole derivative represented by the general formula (1). .

(Wherein R ¹¹ and R ¹³ may be the same as or different from each other, hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, Ar ¹¹ represents any of an arylalkyl group and an acyl group having 1 to 7 carbon atoms, Ar ¹¹ represents any of an aryl group having 6 to 25 carbon atoms and a heteroaryl group having 5 to 9 carbon atoms, and R ¹² represents Any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms, R ¹⁴ is hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, In the substituent represented by the general formula (2), R ¹⁵ represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 25 carbon atoms. , C5-C9 heteroaryl group, arylalkyl Group, or an acyl group having 1 to 7 carbon atoms, ^{Ar 12} represents an aryl group having 6 to 25 carbon atoms, any of the heteroaryl group having 5 to 9 carbon ^{atoms, R 16} is hydrogen, It represents either an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms.)

  In the above structure, the inorganic compound is preferably a substance that exhibits an electron accepting property with respect to the carbazole derivative represented by the general formula (1). Specifically, an oxide of a transition metal is desirable, and in particular, titanium oxide, vanadium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, One or more of hafnium oxide, tantalum oxide, and silver oxide are preferable.

In the general formula (1), any one of R ¹¹ and R ¹³ is preferably an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms. More preferably, R ¹¹ and R ¹³ are preferably any of an aryl group having 6 to 25 carbon atoms and a heteroaryl group having 5 to 9 carbon atoms. When the substituent bonded to nitrogen of the carbazole skeleton is an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms, an effect of improving carrier transportability can be obtained.

In the general formula (1), R ¹² is preferably any one of hydrogen, a tert-butyl group, a phenyl group, and a biphenyl group.

In the general formula (1), R ¹⁴ is preferably any one of hydrogen, a tert-butyl group, a phenyl group, and a biphenyl group.

In the general formula (1), R ¹⁴ is preferably a substituent represented by the general formula (2). When R ¹⁴ is a substituent represented by the general formula (2), a carbazole derivative having higher heat resistance can be obtained. In the general formula ^{(2), R 15} is preferably an heteroaryl group an aryl group or a C 5-9 having 6 to 25 carbon atoms. When the substituent bonded to nitrogen of the carbazole skeleton is an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms, an effect of improving carrier transportability can be obtained. In the general formula (2), R ¹⁶ is preferably any one of hydrogen, a tert-butyl group, a phenyl group, and a biphenyl group.

  Of the carbazole derivatives represented by the general formula (1), it is preferable to use a carbazole derivative represented by the following general formula (3).

(In the formula, R ²¹ is hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, an arylalkyl group, or an acyl group having 1 to 7 carbon atoms. R ²² represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms, and R ²³ represents a substituent represented by the general formula (4). In the substituent represented by the general formula (4), R ²⁴ is hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, or arylalkyl. A group, an acyl group having 1 to 7 carbon atoms, Ar ²¹ represents an aryl group having 6 to 25 carbon atoms, or a heteroaryl group having 5 to 9 carbon atoms, and R ²⁵ represents hydrogen, Alkyl group having 1 to 6 carbon atoms, aryl group having 6 to 12 carbon atoms Re represents how.)

In the above configuration, R ²² is preferably any one of hydrogen, a tert-butyl group, a phenyl group, and a biphenyl group.

  More preferably, among the carbazole derivatives represented by the general formula (1), it is preferable to use the carbazole derivative represented by the general formula (5).

(In the formula, R ²¹ is hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, an arylalkyl group, or an acyl group having 1 to 7 carbon atoms. R ²² and R ²³ each represent a substituent represented by the general formula (6), and in the substituent represented by the general formula (6), R ²⁴ is hydrogen, having 1 to 6 carbon atoms. It represents any of an alkyl group, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, an arylalkyl group, and an acyl group having 1 to 7 carbon atoms, Ar ²¹ has 6 to 25 carbon atoms An aryl group or a heteroaryl group having 5 to 9 carbon atoms is represented, and R ²⁵ represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.)

In the above configuration, R ²⁵ is preferably any one of hydrogen, a tert-butyl group, a phenyl group, and a biphenyl group.

In the above structure, R ²¹ is preferably an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms.

  When the substituent bonded to nitrogen of the carbazole skeleton is an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms, an effect of improving carrier transportability can be obtained.

  Moreover, it is preferable to use the carbazole derivative represented by the general formula (7) among the carbazole derivatives represented by the general formula (1).

(In the formula, Ar ³¹ represents a phenyl group or a naphthyl group.)

  Moreover, it is preferable to use the carbazole derivative represented by the general formula (8) among the carbazole derivatives represented by the general formula (1).

(In the formula, Ar ⁴¹ and Ar ⁴² may be the same or different and each represents a phenyl group or a naphthyl group.)

  Further, the composite material of the present invention can be used for a light-emitting element. Therefore, the light-emitting element of the present invention includes a layer containing a light-emitting substance between a pair of electrodes, and the layer containing a light-emitting substance has a layer containing the above composite material.

  In the above structure, the layer containing the composite material of the present invention may be provided so as to be in contact with an electrode functioning as an anode of the pair of electrodes, or may be provided so as to be in contact with an electrode functioning as a cathode. Good. One layer may be provided so as to be in contact with each of the pair of electrodes.

  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) in its category. In addition, a module in which a connector such as an FPC (Flexible Printed Circuit) or TAB (Tape Automated Bonding) tape or TCP (Tape Carrier Package) is attached to the light emitting device, or a printed wiring board provided on the end of the TAB tape or TCP In addition, a module in which an IC (integrated circuit) is directly mounted on a light emitting element by a COG (Chip On Glass) method is also included in the light emitting device.

  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 practicing the present invention, a composite material in which an organic compound and an inorganic compound are combined, which is excellent in carrier transportability and carrier injection property into the organic compound, and in the visible light transmittance is provided. can do.

  Since the light-emitting element of the present invention includes a layer including a carbazole derivative represented by the general formula (1) and an inorganic compound that exhibits an electron accepting property with respect to the carbazole derivative represented by the general formula (1), Electrons are transferred between the carbazole derivative and the inorganic compound, and carriers are generated. The drive voltage can be reduced by the occurrence of carriers inherently.

  Further, since the composite material of the present invention has high visible light transmittance, a light-emitting element with high emission efficiency can be obtained by using the composite material for a light-emitting element.

  Further, since the composite material of the present invention is excellent in heat resistance, a light emitting element excellent in heat resistance and durability can be obtained.

  In addition, by using the light-emitting element of the present invention, a light-emitting device with low power consumption and few defects can be provided.

  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 of the present invention will be described. The composite material of the present invention includes a carbazole derivative represented by the following general formula (1) and an inorganic compound.

(Wherein R ¹¹ and R ¹³ may be the same as or different from each other, hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, Ar ¹¹ represents any of an arylalkyl group and an acyl group having 1 to 7 carbon atoms, Ar ¹¹ represents any of an aryl group having 6 to 25 carbon atoms and a heteroaryl group having 5 to 9 carbon atoms, and R ¹² represents Any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms, R ¹⁴ is hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, In the substituent represented by the general formula (2), R ¹⁵ represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 25 carbon atoms. , C5-C9 heteroaryl group, arylalkyl Group, or an acyl group having 1 to 7 carbon atoms, ^{Ar 12} represents an aryl group having 6 to 25 carbon atoms, any of the heteroaryl group having 5 to 9 carbon ^{atoms, R 16} is hydrogen, It represents either an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms.)

  Specific examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-hexyl group. Further, it may be a branched alkyl group such as an iso-propyl group or a tert-butyl group.

  Specific examples of the aryl group having 6 to 25 carbon atoms include phenyl group, 4-biphenylyl group, 1-naphthyl group, 2-naphthyl group, 9-anthryl group, 9-phenanthryl group, 1-pyrenyl group, 9 , 9'-dimethyl-2-fluorenyl group, spiro-9,9'-bifluoren-2-yl group and the like. Moreover, the aryl group which has substituents, such as m-tolyl group, p-tolyl group, 2-fluorophenyl group, 3-fluorophenyl group, 4-fluorophenyl group, may be sufficient.

  Specific examples of the heteroaryl group having 5 to 9 carbon atoms include a 2-pyridyl group, an 8-quinolyl group, and a 3-quinolyl group.

  Specific examples of the arylalkyl group include a benzyl group.

  Specific examples of the acyl group having 1 to 7 carbon atoms include an acetyl group, a benzoyl group, and a propionyl group.

In the general formula (1), any one of R ¹¹ and R ¹³ is preferably an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms. More preferably, R ¹¹ and R ¹³ are preferably any of an aryl group having 6 to 25 carbon atoms and a heteroaryl group having 5 to 9 carbon atoms. When the substituent bonded to nitrogen of the carbazole skeleton is an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms, an effect of improving carrier transportability can be obtained.

In the general formula (1), R ¹² is preferably any one of hydrogen, a tert-butyl group, a phenyl group, and a biphenyl group.

In the general formula (1), R ¹⁴ is preferably any one of hydrogen, a tert-butyl group, a phenyl group, and a biphenyl group.

In the general formula (1), R ¹⁴ is preferably a substituent represented by the general formula (2). When R ¹⁴ is a substituent represented by the general formula (2), a carbazole derivative having higher heat resistance can be obtained. In the general formula ^{(2), R 15} is preferably an heteroaryl group an aryl group or a C 5-9 having 6 to 25 carbon atoms. When the substituent bonded to nitrogen of the carbazole skeleton is an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms, an effect of improving carrier transportability can be obtained. In the general formula (2), R ¹⁶ is preferably any one of hydrogen, a tert-butyl group, a phenyl group, and a biphenyl group.

Of the carbazole derivatives having the structure represented by the general formula (1), a carbazole derivative having a structure represented by the following general formula (3) is preferable because it can be easily synthesized.
(In the formula, R ²¹ is hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, an arylalkyl group, or an acyl group having 1 to 7 carbon atoms. R ²² represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms, and R ²³ represents a substituent represented by the general formula (4). In the substituent represented by the general formula (4), R ²⁴ is hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, or arylalkyl. A group, an acyl group having 1 to 7 carbon atoms, Ar ²¹ represents an aryl group having 6 to 25 carbon atoms, or a heteroaryl group having 5 to 9 carbon atoms, and R ²⁵ represents hydrogen, Alkyl group having 1 to 6 carbon atoms, aryl group having 6 to 12 carbon atoms Re represents how.)

In the above configuration, R ²² is preferably any one of hydrogen, a tert-butyl group, a phenyl group, and a biphenyl group.

Of the carbazole derivatives represented by the general formula (1), a carbazole derivative having a structure represented by the following general formula (5) is preferable.
(In the formula, R ²¹ is hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, an arylalkyl group, or an acyl group having 1 to 7 carbon atoms. R ²² and R ²³ each represent a substituent represented by the general formula (6), and in the substituent represented by the general formula (6), R ²⁴ is hydrogen, having 1 to 6 carbon atoms. It represents any of an alkyl group, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, an arylalkyl group, and an acyl group having 1 to 7 carbon atoms, Ar ²¹ has 6 to 25 carbon atoms An aryl group or a heteroaryl group having 5 to 9 carbon atoms is represented, and R ²⁵ represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms.)

In the above configuration, R ²⁵ is preferably any one of hydrogen, a tert-butyl group, a phenyl group, and a biphenyl group.

In the above structure, R ²⁴ is preferably an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms.

In the above structure, R ²¹ is preferably an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms.

  Of the carbazole derivatives represented by the general formula (1), a carbazole derivative having a structure represented by the following general formula (7) is preferable.

(In the formula, Ar ³¹ represents a phenyl group or a naphthyl group.)

  Moreover, it is preferable that it is a carbazole derivative which has a structure shown by following General formula (8).

(In the formula, Ar ⁴¹ and Ar ⁴² may be the same or different and each represents a phenyl group or a naphthyl group.)

  Specific examples of the carbazole derivative used in the present invention include carbazole derivatives represented by the following structural formulas (9) to (71). However, the present invention is not limited to these.

The carbazole derivatives represented by the structural formulas (9) to (20) are those in the case where R ¹² in the general formula (1) is hydrogen, and the carbazole derivatives represented by the structural formulas (21) to (34) are represented by the general formula (1). R ¹² in the formula is an alkyl group.

The carbazole derivatives represented by the structural formulas (35) to (48) have a structure in which the same substituent is bonded to the carbazole skeleton, and are easier to synthesize than a carbazole derivative having a structure in which different substituents are bonded. That is, in the general formula (3), when R ²² and R ²³ have the same structure represented by the general formula (4), the same substituent may be bonded to the carbazole skeleton, so that the synthesis is easy. It becomes.

  Moreover, the carbazole derivative of the present invention may have fluorine as shown in the structural formulas (49) to (57).

  As shown in structural formulas (58) to (69), an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms is preferably bonded to the 6-position of the carbazole skeleton. By having a substituent of an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms at the 6-position of the carbazole skeleton, the carbazole skeleton is chemically stabilized and side reactions can be suppressed.

  As a method for synthesizing the carbazole derivative used in the present invention, various reactions can be applied. For example, the method shown to the following reaction scheme (A-1) and reaction scheme (A-2) is mentioned. However, the synthesis method of the carbazole derivative used in the present invention is not limited to this.

  The inorganic compound used in the composite material of the present invention is preferably a transition metal oxide. Specifically, titanium oxide, zirconium oxide, hafnium oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, Examples include tungsten oxide, manganese oxide, and rhenium oxide. In particular, vanadium oxide, molybdenum oxide, tungsten 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 and easy to handle.

  In addition, the manufacturing method of the composite material of this invention may use what kind of method regardless of a wet method and a dry method. For example, the composite material of the present invention can be manufactured by co-evaporation of a carbazole derivative and an inorganic compound. Molybdenum oxide is easy to evaporate in a vacuum and is preferable from the viewpoint of the manufacturing process.

  By including the carbazole derivative represented by the general formula (1) and the inorganic compound, a composite material having no absorption peak in the visible light region can be obtained. Therefore, a composite material with high visible light transmittance can be obtained.

  In addition, by including the carbazole derivative represented by the general formula (1) and the inorganic compound, the carbazole derivative represented by the general formula (1) interacts with the inorganic compound, and the composite has excellent carrier injecting property and carrier transporting property. Material can be obtained. Note that when the interaction between the carbazole derivative represented by the general formula (1) and the inorganic compound is large, an absorption spectrum is generated in the near infrared region. Therefore, the composite material of the present invention may have an absorption peak between 800 nm and 1300 nm. preferable.

Further, since the carbazole derivative represented by the general formula (1) has a high glass transition point, the composite material of the present invention is excellent in heat resistance.

  Therefore, the composite material of the present invention can be used for a light-emitting element, a semiconductor element such as a photoelectric conversion element or a thin film transistor. By using the composite material of the present invention, the driving voltage can be reduced. Moreover, since it is excellent in the transmittance | permeability of visible light, an efficient semiconductor element can be obtained by using for a light emitting element or a photoelectric conversion element.

(Embodiment 2)
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 mode of the light-emitting element of the present invention will be 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% 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. In the case where the first electrode is used as an anode, the work function is high (work function). It is preferably formed .0eV or higher) and the like.

  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 the carbazole derivative represented by the general formula (1) and the inorganic compound.

The second layer 104 is formed using a substance having a high hole-transport property, such as 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: α-NPD) or N, N′—. Bis (3-methylphenyl) -N, N′-diphenyl- [1,1′-biphenyl] -4,4′-diamine (abbreviation: TPD), 4,4 ′, 4 ″ -tris (N, N -Diphenylamino) aromatic such as triphenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA) It is a layer made of an amine-based compound (that is, having a benzene ring-nitrogen bond). 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. Note that the second layer 104 is not limited to a single layer, and may be a stack of two or more layers including any of the above substances.

The third layer 105 is a layer including a substance having a high light-emitting property. For example, a highly luminescent substance such as N, N′-dimethylquinacridone (abbreviation: DMQd) or 3- (2-benzothiazolyl) -7-diethylaminocoumarin (abbreviation: coumarin 6) and tris (8-quinolinolato) aluminum (abbreviation) : Alq ₃ ) and 9,10-di (2-naphthyl) anthracene (abbreviation: DNA), etc., which are freely combined with a material having high carrier transportability and good film quality (that is, difficult to crystallize). However, since Alq ₃ and DNA are highly luminescent materials, these materials may be used alone, and the third layer 105 may be used.

The fourth layer 106 is formed using a substance having a high electron-transport property, such as tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), 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), etc., having a quinoline skeleton or a benzoquinoline skeleton It is a layer made of a metal 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 accelerating electron injection between the second electrode 107 and the light-emitting layer by stacking with the second electrode, regardless of the work function, Al, Ag, Various conductive materials such as 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 ₃ can be used.

  Alternatively, the first layer 103, the second layer 104, the third layer 105, and the fourth layer 106 may be formed by an evaporation method, an inkjet method, a spin coating method, or the like. 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 made of a light-transmitting substance, light emission is extracted from the substrate side through the first electrode 102 as shown in FIG. Further, in the case where only the second electrode 107 is made of a light-transmitting substance, light emission is extracted from the opposite side of the substrate through the second electrode 107 as shown in FIG. When both the first electrode 102 and the second electrode 107 are made of a light-transmitting substance, as shown in FIG. 1C, light is emitted from the first electrode 102 and the second electrode 107. 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. As long as it has a layer including the composite material described in Embodiment Mode 1, other than the above may be used.

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) The layer made of the substance having a high transportability) may be freely combined with the layer containing the composite material of the present invention. Alternatively, a carrier recombination site may be controlled by providing a layer made of a silicon oxide film or the like over the first electrode 102.

  A light-emitting element illustrated in FIG. 2 includes a first layer 303 formed using a substance having a high electron-transport property, a second layer 304 containing a substance having a high light-emitting property, and a hole transport over the first electrode 302 functioning as a cathode. A third layer 305 made of a highly conductive substance, a fourth layer 306 which is a layer containing the composite material of the present invention, and a second electrode 307 functioning as an anode are stacked in this order. 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.

  The light-emitting element of the present invention includes the composite material shown in Embodiment Mode 1, that is, a layer containing a carbazole derivative represented by the general formula (1) and an inorganic compound. The composite material of the present invention has high electrical conductivity due to the intrinsic generation of carriers, and thus low voltage driving of the light emitting element can be realized.

  In addition, since the composite material used in the present invention has high visible light transmittance, light emitted from the light-emitting layer can be efficiently extracted to the outside.

  In addition, since the composite material used in the present invention has high visible light transmittance, reduction in light extraction efficiency 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, since the composite material of the present invention includes an organic compound having a high glass transition point and also includes an inorganic compound and is excellent in heat resistance, the light-emitting element of the present invention has heat resistance and durability. Is excellent.

  Further, by increasing the thickness of the layer containing the composite material, a short circuit due to dust, impact, or the like 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 3)
In this embodiment, a light-emitting element having a structure different from that described in Embodiment 2 will be described with reference to FIGS. In the structure described in this embodiment mode, a layer containing the composite material of the present invention can be provided so as to be in contact with an electrode functioning as a cathode.

  FIG. 5A shows an example of the structure of the light-emitting element of the present invention. A first layer 411, a second layer 412, and a third layer 413 are stacked between the first electrode 401 and the second electrode 402. In this embodiment, the case where the first electrode 401 functions as an anode and the second electrode 402 functions as a cathode is described.

  The same structure as that in Embodiment 2 can be applied to the first electrode 401 and the second electrode 402. The first layer 411 is a layer containing a substance having high light-emitting properties. The second layer 412 is a layer including one compound selected from electron donating substances and a compound having a high electron-transport property, and the third layer 413 includes the composite material described in Embodiment 1. Is a layer. The electron donating substance contained in the second layer 412 is preferably an alkali metal or alkaline earth metal and oxides or salts thereof. Specifically, lithium, cesium, calcium, lithium oxide, calcium oxide, barium oxide, cesium carbonate, and the like can be given.

  With this configuration, as shown in FIG. 5A, by applying a voltage, electrons are exchanged near the interface between the second layer 412 and the third layer 413, and the electrons and Holes are generated and the second layer 412 transports electrons to the first layer 411, while the third layer 413 transports holes to the second electrode 402. In other words, the second layer 412 and the third layer 413 together serve as a carrier generation layer. In addition, it can be said that the third layer 413 has a function of transporting holes to the second electrode 402.

  In addition, the third layer 413 exhibits extremely high hole injecting property and hole transporting property. Therefore, the drive voltage can be reduced. In addition, when the third layer 413 is thickened, an increase in driving voltage can be suppressed.

  Further, even if the third layer 413 is thickened, an increase in driving voltage can be suppressed. Therefore, the thickness of the third layer 413 can be freely set, and light emission from the first layer 411 can be extracted. Efficiency can be improved. In addition, the thickness of the third layer 413 can be set so that the color purity of light emission from the first layer 411 is improved. In addition, the third layer 413 has a high visible light transmittance, and can suppress a reduction in light extraction efficiency due to the increase in thickness.

Further, taking FIG. 5A as an example, when the second electrode 402 is formed by sputtering, damage to the first layer 411 containing a light-emitting substance can be reduced.

  Note that the light-emitting element of this embodiment also has various variations by changing materials of the first electrode 401 and the second electrode 402. The schematic diagram is shown in FIG. 5 (b), FIG. 5 (c) and FIG. In FIG. 5B, FIG. 5C, and FIG. 6, the reference numerals in FIG. Reference numeral 400 denotes a substrate carrying the light emitting element of the present invention.

  FIG. 5 shows an example in which the first layer 411, the second layer 412, and the third layer 413 are configured in this order from the substrate 400 side. At this time, the first electrode 401 is made light transmissive and the second electrode 402 is made light-shielding (particularly reflective) so that light is emitted from the substrate 400 side as shown in FIG. Become. In addition, the first electrode 401 is made light-shielding (particularly reflective) and the second electrode 402 is made light-transmissive so that light is emitted from the opposite side of the substrate 400 as shown in FIG. It becomes. Further, by making both the first electrode 401 and the second electrode 402 light transmissive, light is emitted to both the substrate 400 side and the opposite side of the substrate 400 as shown in FIG. Configuration is also possible.

  FIG. 6 shows an example in which the third layer 413, the second layer 412, and the first layer 411 are configured in this order from the substrate 400 side. At this time, the first electrode 401 is made light-shielding (particularly reflective), and the second electrode 402 is made light-transmissive so that light is extracted from the substrate 400 side as shown in FIG. . In addition, the first electrode 401 is made light transmissive and the second electrode 402 is made light-shielding (particularly reflective), whereby light is extracted from the opposite side of the substrate 400 as shown in FIG. 6B. Become. Further, by making both the first electrode 401 and the second electrode 402 light transmissive, light is emitted to both the substrate 400 side and the opposite side of the substrate 400 as shown in FIG. Configuration is also possible.

  Note that in the case of manufacturing the light-emitting element in this embodiment, various methods can be used regardless of a wet method or a dry method.

  Further, as illustrated in FIG. 5, after the first electrode 401 is formed, the first layer 411, the second layer 412, and the third layer 413 are sequentially stacked to form the second electrode 402. Alternatively, as shown in FIG. 6, after the second electrode 402 is formed, the third layer 413, the second layer 412, and the first layer 411 are sequentially stacked to form the first electrode 401. May be.

  Note that this embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 4)
In this embodiment, a light-emitting element having a structure different from those described in Embodiments 2 and 3 will be described with reference to FIGS. In the structure described in this embodiment mode, a layer including the composite material of the present invention can be provided so as to be in contact with two electrodes of the light-emitting element.

  FIG. 3A shows an example of the structure of the light-emitting element of the present invention. A first layer 211, a second layer 212, a third layer 213, and a fourth layer 214 are stacked between the first electrode 201 and the second electrode 202. In this embodiment, the case where the first electrode 201 functions as an anode and the second electrode 202 functions as a cathode is described.

  The first electrode 201 and the second electrode 202 can have the same structure as that in Embodiment 2. The first layer 211 is a layer including the composite material described in Embodiment 1, and the second layer 212 is a layer including a substance having a high light-emitting property. The third layer 213 is a layer including an electron-donating substance and a compound having a high electron-transport property, and the fourth layer 214 is a layer including the composite material described in Embodiment 1. The electron donating substance contained in the third layer 213 is preferably an alkali metal or alkaline earth metal and oxides or salts thereof. Specifically, lithium, cesium, calcium, lithium oxide, calcium oxide, barium oxide, cesium carbonate, and the like can be given.

  With such a configuration, as shown in FIG. 3A, when a voltage is applied, electrons are transferred near the interface between the third layer 213 and the fourth layer 214, and the electrons and Holes are generated and the third layer 213 transports electrons to the second layer 212, while the fourth layer 214 transports holes to the second electrode 202. That is, the third layer 213 and the fourth layer 214 together serve as a carrier generation layer. In addition, it can be said that the fourth layer 214 has a function of transporting holes to the second electrode 202. Note that a tandem light-emitting element can be obtained by stacking the second layer and the third layer again between the fourth layer 214 and the second electrode 202.

In addition, the first layer 211 and the fourth layer 214 exhibit extremely high hole injecting property and hole transporting property. Therefore, the driving voltage of the light emitting element can be reduced.
In addition, when the first layer 211 and the fourth layer 214 are thickened, an increase in driving voltage can be suppressed.

  Further, even if the first layer 211 and the fourth layer 214 are thickened, an increase in driving voltage can be suppressed. Therefore, the thicknesses of the first layer 211 and the fourth layer 214 can be freely set. In addition, the extraction efficiency of light emission from the second layer 212 can be improved. In addition, the thickness of the first layer 211 or the fourth layer 214 can be set so that the color purity of light emission from the second layer 212 is improved. In addition, the first layer 211 and the fourth layer 214 have high visible light transmittance, and can suppress a reduction in the efficiency of external extraction of light emission due to thickening.

In addition, the light emitting element of this embodiment can make the anode side and the cathode side of the second layer responsible for the light emitting function very thick, and can effectively prevent a short circuit of the light emitting element. Further, taking FIG. 3A as an example, when the second electrode 202 is formed by sputtering, damage to the second layer 212 containing a light-emitting substance can be reduced. Furthermore, by configuring the first layer 211 and the fourth layer 214 with the same material, layers composed of the same material can be provided on both sides of the layer responsible for the light emitting function, thereby suppressing stress strain. Can also be expected.

  Note that the light-emitting element of this embodiment also has various variations by changing materials of the first electrode 201 and the second electrode 202. The schematic diagram is shown in FIG. 3 (b), FIG. 3 (c) and FIG. In FIGS. 3B, 3C, and 4, the reference numerals in FIG. 3A are cited. Reference numeral 200 denotes a substrate carrying the light emitting element of the present invention.

  FIG. 3 shows an example in which the first layer 211, the second layer 212, the third layer 213, and the fourth layer 214 are configured in this order from the substrate 200 side. At this time, the first electrode 201 is light-transmitting and the second electrode 202 is light-shielding (particularly reflective) so that light is emitted from the substrate 200 side as shown in FIG. Become. Further, the first electrode 201 is made light-shielding (particularly reflective), and the second electrode 202 is made light-transmissive so that light is emitted from the opposite side of the substrate 200 as shown in FIG. It becomes. Further, by making both the first electrode 201 and the second electrode 202 light transmissive, light is emitted to both the substrate 200 side and the opposite side of the substrate 200 as shown in FIG. Configuration is also possible.

  FIG. 4 shows an example in which the fourth layer 214, the third layer 213, the second layer 212, and the first layer 211 are configured in this order from the substrate 200 side. At this time, the first electrode 201 is made light-shielding (particularly reflective), and the second electrode 202 is made light-transmissive so that light is extracted from the substrate 200 side as shown in FIG. . Further, the first electrode 201 is made light-transmitting and the second electrode 202 is made light-shielding (particularly reflective), whereby light is extracted from the opposite side of the substrate 200 as shown in FIG. Become. Furthermore, by making both the first electrode 201 and the second electrode 202 light transmissive, light is emitted to both the substrate 200 side and the opposite side of the substrate 200 as shown in FIG. Configuration is also possible.

  Note that the first layer 211 includes one compound selected from an electron-donating substance and a compound having a high electron-transport property, the second layer 212 includes a light-emitting substance, and the third layer. Reference numeral 213 denotes a layer including the composite material described in Embodiment 1, and the fourth layer 214 includes one compound selected from electron-donating substances and a compound having a high electron-transport property. It is also possible.

  Note that in the case of manufacturing the light-emitting element in this embodiment, various methods can be used regardless of a wet method or a dry method.

  Further, as illustrated in FIG. 3, after the first electrode 201 is formed, the first layer 211, the second layer 212, the third layer 213, and the fourth layer 214 are sequentially stacked. 4, or after forming the second electrode 202, as shown in FIG. 4, the fourth layer 214, the third layer 213, the second layer 212, and the first layer The layer 211 may be sequentially stacked to form the first electrode.

  Note that this embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 5)
In this embodiment, a light-emitting element having a structure different from the structures shown in Embodiments 2 to 4 will be described. The structure described in this embodiment is a structure in which the composite material of the present invention is applied as a charge generation layer of a light-emitting element having a structure in which a plurality of light-emitting units are stacked.

  In this embodiment, a light-emitting element having a structure in which a plurality of light-emitting units are stacked (hereinafter referred to as a tandem element) will be described. That is, the light-emitting element has a plurality of light-emitting units between the first electrode and the second electrode. FIG. 31 shows a tandem element in which two light emitting units are stacked.

  In FIG. 31, a first light emitting unit 511 and a second light emitting unit 512 are stacked between a first electrode 501 and a second electrode 502. A charge generation layer 513 is formed between the first light emitting unit 511 and the second light emitting unit 512.

  Various materials can be used for the first electrode 501 and the second electrode 502.

  The first light-emitting unit 511 and the second light-emitting unit 512 can have various configurations.

  The charge generation layer 513 includes the composite material of the present invention described in Embodiment Mode 1. Since the composite material of the present invention has a high visible light transmittance, the transmittance of light emitted from the first light-emitting unit and the second light-emitting unit is high, and the external extraction efficiency can be improved.

  Note that the charge generation layer 513 may be formed by combining the composite material of the present invention and various materials. For example, as shown in Embodiment Mode 3, a layer made of the composite material of the present invention and a layer containing one compound selected from electron donating substances and a compound having a high electron transporting property are combined. It may be formed. Moreover, you may form combining the layer which consists of a material of this invention, and a transparent conductive film.

  Although the light-emitting element having two light-emitting units has been described in this embodiment mode, the material of the present invention can also be applied to a light-emitting element in which three or more light-emitting units are stacked. For example, a light emitting element in which three light emitting units are stacked is stacked in the order of a first light emitting unit, a first charge generating layer, a second light emitting unit, a second charge generating layer, and a third light emitting unit. However, the composite material of the present invention may be contained only in any one of the charge generation layers, or may be contained in all the charge generation layers.

  Note that this embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 6)
In this embodiment mode, optical design of a light-emitting element will be described.

In the light-emitting elements described in any of Embodiments 2 to 5, at least one of the thicknesses of each layer excluding the first electrode and the second electrode is different for each light-emitting element that emits each emission color. Thus, the light extraction efficiency for each emission color can be increased.

For example, as illustrated in FIG. 10, a light emitting element that emits red color (R), green color (G), and blue color (B) includes a first electrode 1101 that is a reflective electrode, and a light-transmitting property. And the second layer 1101R, 1111G, 1111B, the second layer 1112R, 1112G, 1112B, the third layer 1113R, 1113G, 1113B, the fourth layer 1114R, 1114G and 1114B. Then, the first layers 1111R, 1111G, and 1111B are made different for each emission color.

Note that in the light-emitting element illustrated in FIG. 10, when voltage is applied so that the potential of the first electrode 1101 is higher than the potential of the second electrode 1102, the first layer 1111 (R, G, B) Holes are injected into the second layer 1112 (R, G, B). Electrons are transferred in the vicinity of the interface between the third layer 1113 (R, G, B) and the fourth layer 1114 (R, G, B), and electrons and holes are generated. The third layer 1113 (R, G, B) transports electrons to the second layer 1112 (R, G, B), while the fourth layer 1114 (R, G, B) transports holes to the second electrode 1102. To do. Holes and electrons recombine in the second layer 1112 (R, G, B), which brings the light-emitting substance into an excited state. The excited luminescent material emits light when returning to the ground state.

As shown in FIG. 10, by making the film thicknesses of the first layers 1111R, 1111G, and 1111B different for each luminescent color, the light is reflected by the first electrode and directly recognized by the first electrode. It is possible to prevent a decrease in light extraction efficiency due to a difference in optical path between the case where recognition is performed through the second electrode.

Specifically, when light is incident on the first electrode, phase inversion occurs in the reflected light, resulting in a light interference effect. As a result, the optical distance between the light emitting region and the reflective electrode, that is, the refractive index × distance is (2m−1) / 4 times the emission wavelength (m is an arbitrary positive integer), that is, 1/4, 3/4. When the ratio is 5/4, etc., the efficiency of taking out the emitted light is increased. On the other hand, when m / 2 times (m is an arbitrary positive integer), that is, 1/2, 1, 3/2.

Therefore, in the light emitting device of the present invention, the optical distance between the light emitting region and the reflective electrode, that is, the refractive index × distance is (2m−1) / 4 times the emission wavelength (m is an arbitrary positive integer). The film thickness of any of the first to fourth layers is made different for each light emitting element.

In particular, in the first layer to the fourth layer, the thickness of the layer between the layer where the electrons and holes are recombined and the reflective electrode may be different, but from the layer where the electrons and holes are recombined. The film thickness between the light-transmitting electrodes may be different. Furthermore, the film thicknesses of both may be different. As a result, the emitted light can be efficiently extracted outside.

In order to change the film thickness of any of the first layer to the fourth layer, it is necessary to increase the thickness of the layer. The light-emitting element of the present invention is characterized in that the layer including the composite material described in Embodiment Mode 1 is used for the layer to be thickened.

In general, when the thickness of the light emitting element layer is increased, the driving voltage increases, which is not preferable. However, when the composite material described in Embodiment 1 is used for the layer to be thickened, the driving voltage itself can be lowered, and an increase in driving voltage due to the thickening can be suppressed.

  In FIG. 10, the optical distance between the light emitting region of the red light emitting element (R) and the reflective electrode is 1/4 times the light emitting wavelength, and the light emitting region of the green light emitting element (G) and the reflective electrode The optical distance is 3/4 times the emission wavelength, and the optical distance between the light emitting region of the blue light emitting element (B) and the reflective electrode is 5/4 times the emission wavelength. Note that the present invention is not limited to this value, and the value of m can be set as appropriate. As shown in FIG. 10, the value of m, which is (2m−1) / 4 times the emission wavelength, may be different for each light emitting element.

Further, by increasing the thickness of any of the first to fourth layers, the first electrode and the second electrode can be prevented from being short-circuited, and mass productivity can be improved. preferable.

As described above, in the light-emitting element of the present invention, the film thicknesses of at least the first layer to the fourth layer can be made different for each emission color. At this time, it is preferable that the film thickness of a layer between the layer where the electrons and holes are recombined and the reflective electrode be different for each emission color. Further, the layer that needs to be thicker is preferably a layer containing the composite material described in Embodiment Mode 1 because the driving voltage is not increased.

  Note that although this embodiment mode is described using the light-emitting element having the structure described in Embodiment Mode 4, it can be combined with any other embodiment mode as appropriate.

(Embodiment 7)
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 FIGS. 7A is a top view illustrating the light-emitting device, and FIG. 7B is a cross-sectional view taken along lines A-A ′ and B-B ′ in FIG. 7A. 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, a material having a high work function is preferably used. For example, an ITO film or an indium tin oxide film containing silicon, an indium oxide film containing 2 to 20% zinc oxide, a titanium nitride film, a chromium film, a tungsten film, a Zn film, a Pt film, or the like In addition, a stack of titanium nitride and a film containing aluminum as a main component, a three-layer structure including 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 described in Embodiment 1. 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 material having a low work function (Al, Ag, Li, Ca, or alloys thereof such as MgAg, MgIn, AlLi, CaF ₂ , or calcium nitride) is preferably used. 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.

  Since the light-emitting device of the present invention includes the composite material shown in Embodiment Mode 1, that is, a layer containing a carbazole derivative represented by the general formula (1) and an inorganic compound, the driving voltage can be reduced. And power consumption can be reduced.

  In addition, since the composite material used in the present invention has high visible light transmittance, light emitted from the light-emitting layer can be efficiently extracted to the outside.

  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. In addition, the composite material used in the present invention has high visible light transmittance. 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. 8 is a perspective view of a passive light emitting device manufactured by applying the present invention. In FIG. 8, 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 operates at a low driving voltage.

(Embodiment 8)
In this embodiment mode, an electric device of the present invention including the light-emitting device described in Embodiment Mode 7 as a part thereof will be described. An electric device of the present invention includes the composite material described in Embodiment 1 and includes a display portion with low power consumption. In addition, a highly reliable display portion in which a short circuit due to dust, impact, or the like is suppressed is provided.

  As an electric device manufactured using the light-emitting device of the present invention, a camera such as a video camera or a digital camera, a goggle-type display, a navigation system, a sound reproduction device (car audio, audio component, etc.), a computer, a game device, and portable information Plays back a recording medium such as a terminal (mobile computer, mobile phone, portable game machine, electronic book, etc.) and recording medium (specifically, Digital Versatile Disc (DVD)) and displays the image. And a display device). Specific examples of these electric devices are shown in FIGS.

  FIG. 9A illustrates a television receiver which includes a housing 9101, a support base 9102, a display portion 9103, a speaker portion 9104, a video input terminal 9105, and the like. It is manufactured by using the light emitting device of the present invention for the display portion 9103. By using the light-emitting device of the present invention for the display portion, a television receiver having a display portion with low power consumption and high reliability can be provided. The television receiver includes all information display devices such as a computer, a TV broadcast receiver, and an advertisement display.

  FIG. 9B illustrates a computer, 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. It is manufactured by using the light emitting device of the present invention for the display portion 9203. By using the light-emitting device of the present invention for the display portion, a computer having a highly reliable display portion with low power consumption can be provided.

  FIG. 9C illustrates a goggle type display, which includes a main body 9301, a display portion 9302, and an arm portion 9303. It is manufactured by using the light emitting device of the present invention for the display portion 9302. By using the light-emitting device of the present invention for the display portion, a goggle type display having a display portion with low power consumption and high reliability can be provided.

  FIG. 9D illustrates a mobile phone, 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. It is manufactured by using the light emitting device of the present invention for the display portion 9403. Note that the display portion 9403 can suppress power consumption of the mobile phone by displaying white characters on a black background. By using the light-emitting device of the present invention for the display portion, a cellular phone having a display portion with low power consumption and high reliability can be provided.

  FIG. 9E shows a camera, 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, operation keys 9509, an eyepiece portion. 9510 etc. are included. It is manufactured by using the light emitting device of the present invention for the display portion 9502. By using the light-emitting device of the present invention for the display portion, a camera having a display portion with low power consumption and high reliability 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 electric appliances in various fields. By using the light-emitting device of the present invention, an electric device having a display portion with low power consumption and high reliability can be provided.

  As an example of the carbazole derivative of the present invention, synthesis of 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA1) represented by Structural Formula (12) A method will be described.

[Step 1]
First, a method for synthesizing 3-bromo-9-phenylcarbazole will be described. A synthesis scheme of 3-bromo-9-phenylcarbazole is shown in (A-3).

  24.3 g (100 mmol) of 9-phenylcarbazole was dissolved in 600 mL of glacial acetic acid, 17.8 g (100 mmol) of N-bromosuccinimide was slowly added, and the mixture was stirred overnight at room temperature. This glacial acetic acid solution was added dropwise to 1 L of ice water with stirring. The precipitated white solid was washed 3 times with water. This solid was dissolved in 150 mL of diethyl ether and washed with a saturated aqueous sodium hydrogen carbonate solution and water. This organic layer was dried over magnesium sulfate. This was filtered and the resulting filtrate was concentrated. About 50 mL of methanol was added to the obtained residue and dissolved uniformly. This solution was allowed to stand to precipitate a white solid. This solid was collected and dried to obtain 28.4 g (yield 88%) of 3-bromo-9-phenylcarbazole as a white powder.

[Step 2]
Next, a method for synthesizing 3- (N-phenylamino) -9-phenylcarbazole (abbreviation: PCA) will be described. The synthesis scheme of PCA is shown in (A-4).

Under a nitrogen atmosphere, 19 g (60 mmol) of 3-bromo-9-phenylcarbazole, 340 mg (0.6 mmol) of bis (dibenzylideneacetone) palladium (0), 1.6 g of 1,1-bis (diphenylphosphino) ferrocene ( 3.0 mmol) and sodium-tert-butoxide (13 g, 180 mmol) were added with 110 mL of dehydrated xylene and 7.0 g (75 mmol) of aniline. This was heated and stirred at 90 ° C. for 7.5 hours in a nitrogen atmosphere. After completion of the reaction, about 500 mL of warm toluene was added to this suspension, and this was filtered through Florisil, alumina, and celite. The obtained filtrate was concentrated, hexane-ethyl acetate was added to the residue, and ultrasonic waves were applied. The obtained suspension was filtered, and this residue was dried to obtain 15 g (yield 75%) of 3- (N-phenylamino) -9-phenylcarbazole as a cream powder. The NMR data is shown below. ¹ H-NMR (300 MHz, CDCl ₃ ): δ = 6.84 (t, J = 6.9, 1H), 6.97 (d, J = 7.8, 2H), 7.20-7.61. (M, 13H), 7.90 (s, 1H), 8.04 (d, J = 7.8, 1H). In addition, FIG. 25 shows a ¹ H-NMR chart, and FIG. 26 shows an enlarged portion of 5.0 to 9.0 ppm in FIG.

[Step 3]
A method for synthesizing 3-iodo-9-phenylcarbazole will be described. A synthesis scheme of 3-iodo-9-phenylcarbazole is shown in (A-5).

  24.3 g (100 mmol) of 9-phenylcarbazole was dissolved in 600 mL of glacial acetic acid, 22.5 g (100 mmol) of N-iodosuccinimide was slowly added, and the mixture was stirred overnight at room temperature. The resulting precipitate was filtered, and the filtrate was washed with a saturated sodium hydrogen carbonate solution, water and methanol, and then dried. As a result, 24.7 g (yield 67%) of 3-iodo-9-phenylcarbazole as a white powder was obtained.

  Note that 3-iodo-9-phenylcarbazole can also be synthesized using the following method. A synthesis scheme of 3-iodo-9-phenylcarbazole is shown in (A-5b).

  10 g (10.0 mmol) of 9-phenylcarbazole, 838 mg (5.0 mmol) of potassium iodide, 1.1 g (5.0 mmol) of potassium iodate, and 30 mL of glacial acetic acid were placed in a three-necked flask and refluxed at 120 ° C. for 1 hour. After the reaction, the reaction solution was sufficiently cooled, added to water, extracted with toluene, and the organic layer was washed once with a saturated saline solution and dried over magnesium sulfate. This solution was naturally filtered, and the obtained filtrate was concentrated and recrystallized with acetone and methanol to obtain 8.0 g of a target white solid in a yield of 50%.

  By using the synthesis method shown in the synthesis scheme (A-5b), 3-iodo-9-phenylcarbazole can be synthesized using a less expensive material; therefore, cost can be reduced.

[Step 4]
A method for synthesizing 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA1) is described. A synthesis scheme of PCzPCA1 is shown in (A-6).

Under a nitrogen atmosphere, 3.7 g (10 mmol) of 3-iodo-9-phenylcarbazole, 3.4 g (10 mmol) of PCA, 57 mg (0.1 mmol) of bis (dibenzylideneacetone) palladium (0), tri-tert-butylphosphine Dehydrated xylene 40 mL was added to a mixture of 49 w% hexane solution 200 mL (0.5 mmol) sodium-tert-butoxide 3.0 g (30 mmol). This was heated and stirred at 90 ° C. for 6.5 hours in a nitrogen atmosphere. After completion of the reaction, about 500 mL of warm toluene was added to this suspension, and this was filtered through Florisil, alumina, and celite. The obtained filtrate was concentrated, and the residue was fractionated by silica gel column chromatography (toluene: hexane = 1: 1). This was concentrated, and ethyl acetate-hexane was added to the resulting residue for recrystallization. A cream powder of 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (3.2 g, yield 56%) was obtained. The NMR data is shown below. ¹ H-NMR (300 MHz, DMSO-d): δ = 6.85 (t, J = 7.5, 1H), 6.92 (d, J = 7.8, 2H), 7.17-7. 70 (m, 22H), 8.05 (d, J = 2.1, 2H), 8.12 (d, J = 7.8, 2H). ¹ H-NMR chart is shown in FIG. 11, and an enlarged portion of 6.50 to 8.50 ppm in FIG. 11 is shown in FIG.

  The obtained PCzPCA1 was subjected to thermogravimetry-differential thermal analysis (TG-DTA). TG-DTA: Thermogravimetry-Differential Thermal Analysis (TG-DTA). The result is shown in FIG. In FIG. 19, the left vertical axis represents differential heat (electromotive force (μV) of thermocouple) in differential thermal analysis (DTA), and the right vertical axis represents weight (%; measurement start) in thermogravimetry (TG measurement). The weight expressed with the hour weight as 100%). Furthermore, the lower horizontal axis represents temperature (° C.). In addition, the thermophysical property was evaluated with the temperature increase rate of 10 degree-C / min in nitrogen atmosphere for the measurement using the differential-thermo-thermogravimetry simultaneous measuring apparatus (Seiko Electronics Co., Ltd. make, TG / DTA320 type | mold). As a result, from the relationship between weight and temperature (thermogravimetry), the temperature at which the weight was 95% or less with respect to the weight at the start of measurement under normal pressure was 375 ° C.

  Further, FIG. 13 shows absorption spectra of a toluene solution of PCzPCA1 and a thin film of PCzPCA1. For the measurement, an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550) was used. The solution was put in a quartz cell, and the thin film was deposited on a quartz substrate to prepare a sample. The absorption spectrum obtained by subtracting the absorption spectrum of quartz was shown in FIG. In FIG. 13, the horizontal axis represents wavelength (nm) and the vertical axis represents absorption intensity (arbitrary unit). The maximum absorption wavelength was 320 nm for the PCzPCA1 toluene solution, and 321 nm for the PCzPCA1 thin film. FIG. 14 shows emission spectra of a toluene solution of PCzPCA1 and a thin film of PCzPCA1. In FIG. 14, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). The maximum emission wavelength was 435 nm (excitation wavelength 325 nm) in the case of the toluene solution of PCzPCA1, and 443 nm (excitation wavelength 380 nm) in the case of the thin film of PCzPCA1.

  Further, the HOMO level and the LUMO level in the thin film state of PCzPCA1 were measured. The value of the HOMO level was obtained by converting the ionization potential value measured using a photoelectron spectrometer (manufactured by Riken Keiki Co., Ltd., AC-2) into a negative value. Further, the LUMO level value was obtained by using the absorption edge of the thin film in FIG. 13 as an energy gap and adding it to the HOMO level value. As a result, the HOMO level and the LUMO level were −5.17 eV and −1.82 eV, respectively.

  Moreover, the oxidation reaction characteristic of PCzPCA1 was investigated by cyclic voltammetry (CV) measurement. For the measurement, an electrochemical analyzer (manufactured by BAS Co., Ltd., model number: ALS model 600A) was used.

The solution in the CV measurement uses dehydrated dimethylformamide (DMF) as a solvent and dissolves the supporting electrolyte tetra-n-butylammonium perchlorate (n-Bu ₄ NClO ₄ ) to a concentration of 100 mmol / L. Furthermore, PCzPCA1, which is a measurement object, was prepared by dissolving to a concentration of 1 mmol / L. In addition, as a working electrode, a platinum electrode (manufactured by BAS Co., Ltd., PTE platinum electrode), and as an auxiliary electrode, a platinum electrode (manufactured by BAS Inc., Pt counter electrode for VC-3 ( 5 cm)), and an Ag / Ag ⁺ electrode (manufactured by BAS Co., Ltd., RE5 nonaqueous solvent system reference electrode) was used as a reference electrode.

The oxidation reaction characteristics were examined as follows.
A scan in which the potential of the working electrode with respect to the reference electrode was changed from −0.16 to 0.5 V and then changed from 0.5 V to −0.16 V was taken as one cycle, and 100 cycles were measured. The scan speed for CV measurement was set to 0.1 V / s.

The results of examining the oxidation reaction characteristics of PCzPCA1 are shown in FIG. In FIG. 21, the horizontal axis represents the potential (V) of the working electrode with respect to the reference electrode, and the vertical axis represents the current value (1 × 10 ⁻⁶ A) flowing between the working electrode and the auxiliary electrode.

From FIG. 21, it was found that the oxidation potential was 0.27 V (vs. Ag / Ag ⁺ electrode). In addition, in spite of repeating 100 cycles of scanning, the oxidation reaction shows almost no change in the peak position or peak intensity of the CV curve. From this, it was found that the carbazole derivative of the present invention is extremely stable against the oxidation reaction.

  Further, the glass transition temperature of the obtained compound PCzPCA1 was examined using a differential scanning calorimeter (DSC: Differential Scanning Calorimetry, manufactured by PerkinElmer, model number: Pyris1 DSC). The measurement result by DSC is shown in FIG. From the measurement results, it was found that the glass transition temperature of the obtained compound was 112 ° C. Thus, the obtained compound exhibits a high glass transition temperature of 112 ° C. and has good heat resistance. Further, in FIG. 23, there was no peak indicating crystallization of the obtained compound, and it was found that the obtained compound was a substance that was difficult to crystallize.

  As an example of the carbazole derivative of the present invention, 3,6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA2) represented by Structural Formula (38) ) Will be described.

[Step 1]
A method for synthesizing 3,6-diiodo-9-phenylcarbazole will be described. A synthesis scheme of 3,6-diiodo-9-phenylcarbazole is shown in (A-7).

  24.3 g (100 mmol) of 9-phenylcarbazole was dissolved in 700 mL of glacial acetic acid, 44.9 g (200 mmol) of N-iodosuccinimide was slowly added, and the mixture was stirred overnight at room temperature. The resulting precipitate was filtered, and the filtrate was washed with a saturated aqueous sodium hydrogen carbonate solution, water and methanol, and then dried. As a result, 47.0 g (yield 95%) of 3,6-diiodo-9-phenylcarbazole as a white powder was obtained.

[Step 2]
A method for synthesizing 3,6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA2) will be described. A synthesis scheme of PCzPCA2 is shown in (A-8).

Under a nitrogen atmosphere, 2.5 g (5 mmol) of 3,6-diiodo-9-phenylcarbazole, 3.4 g (10 mmol) of PCA, 30 mg (0.05 mmol) of bis (dibenzylideneacetone) palladium (0), tri-tert -30 mL of dehydrated xylene was added to a mixture of butylphosphine 49 wt% hexane solution 0.2 mL (0.5 mmol) and sodium-tert-butoxide 3.0 g (30 mmol). This was heated and stirred at 90 ° C. for 6.5 hours in a nitrogen atmosphere. After completion of the reaction, about 500 mL of warm toluene was added to this suspension, and this was filtered through Florisil, alumina, and celite. The obtained filtrate was concentrated, and the concentrate was purified by silica gel column chromatography (toluene: hexane = 1: 1). This was concentrated, and ethyl acetate-hexane was added to the resulting concentrated liquid for recrystallization. 2.5 g (yield 55%) of cream powder 3,6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole was obtained. The NMR data is shown below. ¹ H-NMR (300 MHz, DMSO-d): δ = 6.74-6.80 (m, 6H), 7.08-7.64 (m, 33H), 7.94-8.04 (m, 6H). FIG. 15 shows a ¹ H-NMR chart, and FIG. 16 shows an enlarged portion of 6.50 to 8.50 ppm in FIG.

  The obtained PCzPCA2 was subjected to thermogravimetry-differential thermal analysis (TG-DTA). TG-DTA: Thermogravimetry-Differential Thermal Analysis (TG-DTA). The result is shown in FIG. In FIG. 20, the left vertical axis represents differential heat (electromotive force (μV) of thermocouple) in differential thermal analysis (DTA), and the right vertical axis represents weight (%; measurement start) in thermogravimetry (TG measurement). The weight expressed with the hour weight as 100%). Furthermore, the lower horizontal axis represents temperature (° C.). In addition, the thermophysical property was evaluated with the temperature increase rate of 10 degree-C / min in nitrogen atmosphere for the measurement using the differential-thermo-thermogravimetry simultaneous measuring apparatus (Seiko Electronics Co., Ltd. make, TG / DTA320 type | mold). As a result, from the relationship between weight and temperature (thermogravimetry), the temperature at which the weight was 95% or less with respect to the weight at the start of measurement under normal pressure was 476 ° C.

  In addition, FIG. 17 shows absorption spectra of a toluene solution of PCzPCA2 and a thin film of PCzPCA2. For the measurement, an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550) was used. The solution was put in a quartz cell, and the thin film was deposited on a quartz substrate to prepare a sample. The absorption spectrum obtained by subtracting the absorption spectrum of quartz is shown in FIG. In FIG. 17, the horizontal axis represents wavelength (nm) and the vertical axis represents absorption intensity (arbitrary unit). The maximum absorption wavelength was 320 nm in the case of the toluene solution of PCzPCA2, and 320 nm in the case of the thin film of PCzPCA2. FIG. 18 shows emission spectra of a toluene solution of PCzPCA2 and a thin film of PCzPCA2. In FIG. 18, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). The maximum emission wavelength was 442 nm (excitation wavelength: 325 nm) in the case of the toluene solution of PCzPCA2, and 449 nm (excitation wavelength: 320 nm) in the case of the thin film of PCzPCA2.

  Further, the HOMO level and the LUMO level in the thin film state of PCzPCA2 were measured. The value of the HOMO level was obtained by converting the ionization potential value measured using a photoelectron spectrometer (AC-2, manufactured by Riken Keiki Co., Ltd.) into a negative value. The LUMO level value was obtained by using the absorption edge of the thin film in FIG. 17 as an energy gap and adding it to the HOMO level value. As a result, the HOMO level and the LUMO level were −5.10 eV and −1.75 eV, respectively.

  Further, the oxidation characteristics of PCzPCA2 were examined by cyclic voltammetry (CV) measurement. For the measurement, an electrochemical analyzer (manufactured by BAS Co., Ltd., model number: ALS model 600A) was used.

The solution in the CV measurement uses dehydrated dimethylformamide (DMF) as a solvent and dissolves the supporting electrolyte tetra-n-butylammonium perchlorate (n-Bu ₄ NClO ₄ ) to a concentration of 100 mmol / L. Furthermore, PCzPCA2 as a measurement target was prepared by dissolving it to a concentration of 1 mmol / L. In addition, as a working electrode, a platinum electrode (manufactured by BAS Co., Ltd., PTE platinum electrode), and as an auxiliary electrode, a platinum electrode (manufactured by BAS Inc., Pt counter electrode for VC-3 ( 5 cm)), and an Ag / Ag ⁺ electrode (manufactured by BAS Co., Ltd., RE5 nonaqueous solvent system reference electrode) was used as a reference electrode.

  The oxidation reaction characteristics were examined as follows. A scan in which the potential of the working electrode with respect to the reference electrode was changed from −0.01 to 0.33 V and then changed from 0.33 V to −0.01 V was taken as one cycle, and 100 cycles were measured. The scan speed for CV measurement was set to 0.1 V / s.

The result of examining the oxidation reaction characteristic of PCzPCA2 is shown in FIG. In FIG. 22, the horizontal axis represents the potential (V) of the working electrode with respect to the reference electrode, and the vertical axis represents the current value (1 × 10 ⁻⁶ A) flowing between the working electrode and the auxiliary electrode.

From FIG. 22, it was found that the oxidation potential was 0.22 V (vs. Ag ^/ Ag ⁺ electrode). In addition, in spite of repeating 100 cycles of scanning, the oxidation reaction shows almost no change in the peak position or peak intensity of the CV curve. From this, it was found that the carbazole derivative of the present invention is extremely stable against oxidation.

  Further, the glass transition temperature of the obtained compound PCzPCA2 was examined using a differential scanning calorimeter (DSC: Differential Scanning Calorimetry, manufactured by PerkinElmer, model number: Pyris1 DSC). The measurement result by DSC is shown in FIG. From the measurement results, it was found that the glass transition temperature of the obtained compound was 168 ° C. Thus, the obtained compound has a high glass transition temperature of 168 ° C. and has good heat resistance. Moreover, in FIG. 24, the peak showing crystallization of the obtained compound did not exist, and it turned out that the obtained compound is a substance which is hard to crystallize.

  As an example of the carbazole derivative of the present invention, 3- [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole represented by the structural formula (17) (abbreviation: A method for synthesizing PCzPCN1) will be described.

[Step 1]
First, a method for synthesizing 3- [N- (1-naphthyl) amino] -9-phenylcarbazole (abbreviation: PCN) will be described. A synthesis scheme of PCN is shown in (A-9).

Under a nitrogen atmosphere, 3.7 g (10 mmol) of 3-iodo-9-phenylcarbazole, 1.6 g (5 mmol) of 1-aminonaphthalene, 60 mg (0.1 mmol) of bis (dibenzylideneacetone) palladium (0), To a mixture of -tert-butylphosphine 49 wt% hexane solution 0.2 mL (0.5 mmol) and sodium-tert-butoxide 3 g (30 mmol) was added 12 mL of dehydrated xylene. This was heated and stirred at 90 ° C. for 7 hours in a nitrogen atmosphere. After completion of the reaction, about 200 mL of warm toluene was added to this suspension, and this was filtered through Florisil, alumina, and celite. The obtained filtrate was concentrated, and the concentrate was purified by silica gel column chromatography (toluene: hexane = 1: 1). This was concentrated, and the resulting concentrate was recrystallized from ethyl acetate-hexane. A cream powder of 3- [N- (1-naphthyl) amino] -9-phenylcarbazole was obtained. The yield was 1.5 g and 79%. The NMR data is shown below. ¹ H-NMR (300 MHz, DMSO-d): δ = 7.13-7.71 (m, 15H), 7.85-7.88 (m, 1H), 8.03 (s, 1H), 8 .15 (d, J = 7.8, 1H), 8.24 (s, 1H), 8.36-8.39 (m, 1H). FIG. 27 shows a ¹ H-NMR chart, and FIG. 28 shows an enlarged portion of 6.50 to 8.50 ppm in FIG.

[Step 2]
Next, a method for synthesizing 3- [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole (abbreviation: PCzPCN1) will be described. A synthesis scheme of PCzPCN1 is shown in (A-10).

Under a nitrogen atmosphere, 1.8 g (5 mmol) of 3-iodo-9-phenylcarbazole, 2.5 g (6.6 mmol) of PCN, 30 mg (0.05 mmol) of bis (dibenzylideneacetone) palladium (0), tri- 7 mL of dehydrated xylene was added to a mixture of tert-butylphosphine 49 wt% hexane solution 0.2 mL (0.5 mmol) and sodium-tert-butoxide 700 mg (7 mmol). This was heated and stirred at 90 ° C. for 4.5 hours in a nitrogen atmosphere. After completion of the reaction, about 500 mL of warm toluene was added to this suspension, and this was filtered through Florisil, alumina, and celite. The obtained filtrate was concentrated, and the concentrate was purified by silica gel column chromatography (toluene: hexane = 1: 1). This was concentrated, and the resulting concentrate was recrystallized from ethyl acetate-hexane. 2.1 g (yield 62%) of PCzPCN1 as a yellow powder was obtained. The NMR data is shown below. ¹ H-NMR (300 MHz, DMSO-d): δ = 7.04-7.65 (m, 24H), 7.78 (d, J = 8.4, 1H), 7.82 (d, J = 2.1, 2H), 7.88 (d, J = 7.8, 2H), 7.95 (d, J = 8.4, 1H), 8.10 (d, J = 9.0, 1H) ). Further, FIG. 29 shows a ¹ H-NMR chart, and FIG. 30 shows an enlarged portion of 6.50 to 8.50 ppm in FIG.

  Thermogravimetry-differential thermal analysis (TG-DTA) of the obtained PCzPCN1 was performed in the same manner as in Example 1 and Example 2. The result is shown in FIG. In FIG. 40, the left vertical axis represents differential heat (electromotive force (μV) of thermocouple) in differential thermal analysis (DTA), and the right vertical axis represents weight (%; measurement start) in thermogravimetry (TG measurement). The weight expressed with the hour weight as 100%). Furthermore, the lower horizontal axis represents temperature (° C.). In addition, the thermophysical property was evaluated with the temperature increase rate of 10 degree-C / min in nitrogen atmosphere for the measurement using the differential-thermo-thermogravimetry simultaneous measuring apparatus (Seiko Electronics Co., Ltd. make, TG / DTA320 type | mold). As a result, from the relationship between weight and temperature (thermogravimetry), the temperature at which the weight was 95% or less with respect to the weight at the start of measurement under normal pressure was 400 ° C.

  Further, FIG. 41 shows absorption spectra of a toluene solution of PCzPCN1 and a thin film of PCzPCN1. For the measurement, an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550) was used. The solution was put in a quartz cell, and the thin film was deposited on a quartz substrate to prepare a sample. The absorption spectrum obtained by subtracting the absorption spectrum of quartz is shown in FIG. In FIG. 41, the horizontal axis represents wavelength (nm) and the vertical axis represents absorption intensity (arbitrary unit). The maximum absorption wavelength was 314 nm for the PCzPCN1 toluene solution and 320 nm for the PCzPCN1 thin film. In addition, emission spectra of a toluene solution of PCzPCN1 and a thin film of PCzPCN1 are shown in FIG. In FIG. 42, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). The maximum emission wavelength was 475 nm (excitation wavelength: 320 nm) in the case of a toluene solution of PCzPCN1, and 485 nm (excitation wavelength: 320 nm) in the case of a thin film of PCzPCN1.

  Further, the HOMO level and the LUMO level in the thin film state of PCzPCN1 were measured. The value of the HOMO level was obtained by converting the ionization potential value measured using a photoelectron spectrometer (AC-2, manufactured by Riken Keiki Co., Ltd.) into a negative value. The LUMO level value was obtained by using the absorption edge of the thin film in FIG. 41 as an energy gap and adding it to the HOMO level value. As a result, the HOMO level and the LUMO level were −5.15 eV and −2.82 eV, respectively.

  Further, the oxidation characteristics of PCzPCN1 were examined by cyclic voltammetry (CV) measurement. For the measurement, an electrochemical analyzer (manufactured by BAS Co., Ltd., model number: ALS model 600A) was used.

The solution in the CV measurement uses dehydrated dimethylformamide (DMF) as a solvent and dissolves the supporting electrolyte tetra-n-butylammonium perchlorate (n-Bu ₄ NClO ₄ ) to a concentration of 100 mmol / L. Further, PCzPCN1, which is a measurement object, was prepared by dissolving to a concentration of 1 mmol / L. In addition, as a working electrode, a platinum electrode (manufactured by BAS Co., Ltd., PTE platinum electrode), and as an auxiliary electrode, a platinum electrode (manufactured by BAS Inc., Pt counter electrode for VC-3 ( 5 cm)), and an Ag / Ag ⁺ electrode (manufactured by BAS Co., Ltd., RE5 nonaqueous solvent system reference electrode) was used as a reference electrode.

  The oxidation reaction characteristics were examined as follows. A scan in which the potential of the working electrode with respect to the reference electrode was changed from −0.20 to 0.50 V and then changed from 0.50 V to −0.20 V was taken as one cycle, and 100 cycles were measured. The scan speed for CV measurement was set to 0.1 V / s.

The result of examining the oxidation reaction characteristic of PCzPCN1 is shown in FIG. In FIG. 49, the horizontal axis represents the potential (V) of the working electrode with respect to the reference electrode, and the vertical axis represents the current value (1 × 10 ⁻⁶ A) flowing between the working electrode and the auxiliary electrode.
From FIG. 49, it was found that the oxidation potential was 0.25 V (vs. Ag ^/ Ag ⁺ electrode). In addition, in spite of repeating 100 cycles of scanning, the oxidation reaction shows almost no change in the peak position or peak intensity of the CV curve. From this, it was found that the carbazole derivative of the present invention is extremely stable against oxidation.

  Further, the glass transition temperature of the obtained compound PCzPCN1 was examined using a differential scanning calorimeter (DSC: Differential Scanning Calorimetry, manufactured by PerkinElmer, model number: Pyris1 DSC). The measurement result by DSC is shown in FIG. From the measurement results, it was found that the glass transition temperature of the obtained compound was 142 ° C. Thus, the obtained compound has a high glass transition temperature of 142 ° C. and has good heat resistance. Further, in FIG. 50, there was no peak indicating crystallization of the obtained compound, and it was found that the obtained compound was a substance difficult to crystallize.

  In this example, a specific example of a layer including a carbazole derivative represented by the general formula (1) and an inorganic compound having an electron accepting property with respect to the carbazole derivative is illustrated. As the carbazole derivative, 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA1) represented by the structural formula (12) synthesized in Example 1 was used. ) And molybdenum oxide was used as the inorganic compound.

  First, a glass substrate is fixed to a substrate holder in a vacuum deposition apparatus. Then, PCzPCA1 and molybdenum oxide (VI) were put in separate resistance heating evaporation sources, and a layer containing PCzPCA1 and molybdenum oxide was formed by a co-evaporation method in a vacuum state. At this time, co-evaporation was performed so that the weight ratio of PCzPCA1 to molybdenum oxide was 4: 1. Therefore, the molar ratio is PCzPCA1: molybdenum oxide = 1.0: 1.0. The film thickness was 90 nm.

  The result of measuring the absorption spectrum of the PCzPCA1-molybdenum oxide composite film thus formed is shown in C of FIG. For comparison, the absorption spectrum (A in the figure) of the film containing only PCzPCA1 is also shown.

  As can be seen from FIG. 32, the composite film of C showed new absorption that was not seen in the film of PCzPCA1 alone (in the figure, it is a part surrounded by a broken line and has a peak near 1070 nm). This is because PCzPCA1 and molybdenum oxide exchange electrons, and it is considered that molybdenum oxide receives electrons from PCzPCA1 and holes are generated in PCzPCA1.

  Therefore, in the PCzPCA1: molybdenum oxide composite film formed in this embodiment, carriers are generated internally, and the driving voltage of the light emitting element can be reduced.

  Further, as shown in FIG. 32, in the PCzPCA1-molybdenum oxide composite film, no significant absorption peak was observed in the visible light region (400 nm to 700 nm).

  In this example, a specific example of a layer including a carbazole derivative represented by the general formula (1) and an inorganic compound having an electron accepting property with respect to the carbazole derivative is illustrated. Examples of the carbazole derivative include 3,6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole represented by the structural formula (36) synthesized in Example 1. Abbreviation: PCzPCA2) was used, and molybdenum oxide was used as the inorganic compound.

  First, a glass substrate is fixed to a substrate holder in a vacuum deposition apparatus. Then, PCzPCA2 and molybdenum oxide (VI) were put in separate resistance heating evaporation sources, and a layer containing PCzPCA2 and molybdenum oxide was formed by a co-evaporation method in a vacuum state. At this time, co-evaporation was performed so that the weight ratio of PCzPCA2 to molybdenum oxide was 4: 1. Therefore, the molar ratio is PCzPCA2: molybdenum oxide = 1.0: 1.6. The film thickness was 90 nm.

  The result of measuring the absorption spectrum of the PCzPCA2-molybdenum oxide composite film thus formed is shown in C of FIG. For comparison, the absorption spectrum (A in the figure) of the film containing only PCzPCA2 is also shown.

  As can be seen from FIG. 33, the C composite film showed a new absorption that was not observed in the PCzPCA2 single film (in the figure, the portion surrounded by a broken line and has a peak near 960 nm). This is because PCzPCA2 and molybdenum oxide exchange electrons, and it is considered that molybdenum oxide receives electrons from PCzPCA2 and holes are generated in PCzPCA2.

  Therefore, in the PCzPCA2: molybdenum oxide composite film formed in this embodiment, carriers are generated internally, and the driving voltage of the light emitting element can be reduced.

  Further, as shown in FIG. 33, in the PCzPCA2-molybdenum oxide composite film, no significant absorption was observed in the visible light region (400 nm to 700 nm).

  Next, the visible light transmittance of the composite films manufactured in Example 4 and Example 5 is shown in FIG.

  The vertical axis | shaft of FIG. 32 and FIG. 33 is converted into light transmittance from the light absorbency, and the figure compared on the same graph is shown in FIG. In FIG. 34, the wavelength on the horizontal axis is limited to the visible light region (400 nm to 700 nm). As shown in FIG. 34, the transmittance in the visible light region of the PCzPCA1-molybdenum oxide composite film produced in Example 4 and the PCzPCA2-molybdenum oxide composite film produced in Example 5 is about 90% or more. Show.

In addition, FIG. 71 shows the absorbance per 1 μm in blue (450 nm) to red (650 nm) of the PCzPCA1-molybdenum oxide composite film manufactured in Example 4 and the PCzPCA2-molybdenum oxide composite film manufactured in Example 5. As can be seen from FIG. 71, the absorbance per 1 μm of the composite material of the present invention is 2 (μm) ⁻¹ or less in all cases, and the absorbance is small from blue (450 nm) to red (650 nm). Therefore, the composite material of the present invention has high translucency over blue (450 nm), green (520 nm), and red (650 nm), and is suitable for a full color display.

  From the above, it was found that the composite material of the present invention was superior in visible light transmissivity compared to conventional composite materials.

  In this example, a light-emitting element using the composite material of the present invention will be described.

  First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. An indium tin oxide containing silicon oxide, which is a transparent conductive film, was used as a material, and an anode having an electrode size (2 mm × 2 mm) was formed by a sputtering method.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing downward, and PCzPCA1 and molybdenum oxide with a film thickness of 50 nm are formed by co-evaporation. A layer containing was formed. At this time, co-evaporation was performed so that the weight ratio of PCzPCA1 to molybdenum oxide was 4: 2.

  Next, a hole transport layer is formed of a material having excellent hole transport properties. As a material for forming the hole transport layer, various hole transport materials can be used. In this example, α-NPD was formed with a film thickness of 10 nm by a vapor deposition method.

Next, a light emitting layer is formed. Note that holes and electrons recombine in the light emitting layer to emit light. In this example, Alq _{3 as} a host material and coumarin 6 as a guest material are used, and the film thickness is 40 nm by co-evaporation so that coumarin 6 is included in Alq ₃ at a ratio of 1% by weight. Formed.

Next, an electron transport layer is formed. As a material for forming the electron transport layer, various electron transport materials can be used. In this example, Alq ₃ was used and a film thickness of 10 nm was formed by a vapor deposition method.

Next, an electron injection layer is formed. Various electron-injecting materials can be used for the electron-injecting layer. In this example, Alq ₃ and lithium are used, so that lithium is contained in Alq ₃ at a ratio of 1% by weight. It formed with the film thickness of 30 nm by the vapor deposition method.

  In this manner, after forming a layer containing a light emitting substance formed by stacking the layer containing the composite material of the present invention, the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer, the second layer is formed. The electrode is formed by sputtering or vapor deposition. In this embodiment, the second electrode functions as a cathode. In this example, Al was formed by a vapor deposition method.

  Through the above steps, the light-emitting element of this example is manufactured. FIG. 35 shows current-voltage characteristics of the light-emitting element manufactured in this example, FIG. 36 shows luminance-voltage characteristics, and FIG. 37 shows current efficiency-luminance characteristics.

  From FIG. 35, it can be seen that a current easily flows by using the composite material of the present invention for a light-emitting element. In addition, FIG. 36 shows that the driving voltage of the light emitting element is reduced. FIG. 37 shows that the light emission efficiency is high. Since the composite material of the present invention has a high visible light transmittance, it is considered that the light extraction efficiency is improved.

That is, it can be seen that by using the composite material of the present invention for a light-emitting element, a driving voltage for obtaining light emission with constant luminance can be reduced. Specifically, the voltage required to emit light with a luminance of 1000 cd / m ² is 5.2 V in the light-emitting element manufactured in this example, and the current density at this time is 8.4 mA / cm ^2. It was. That is, it can be seen that low voltage driving and low current driving are possible by using the composite material of the present invention for a light emitting element.

  In this example, a light-emitting element using the composite material of the present invention will be described.

  First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. An indium tin oxide containing silicon oxide, which is a transparent conductive film, was used as a material, and an anode having an electrode size (2 mm × 2 mm) was formed by a sputtering method.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing downward, and PCzPCA1 and molybdenum oxide with a film thickness of 50 nm are formed by co-evaporation. A layer containing was formed. At this time, co-evaporation was performed so that the weight ratio of PCzPCA1 to molybdenum oxide was 4: 1.

  Next, a hole transport layer is formed of a material having excellent hole transport properties. As a material for forming the hole transport layer, various hole transport materials can be used. In this example, α-NPD was formed with a film thickness of 10 nm by a vapor deposition method.

Next, a light emitting layer is formed. Note that holes and electrons recombine in the light emitting layer to emit light. In this example, Alq _{3 as} a host material and coumarin 6 as a guest material are used, and the film thickness is 40 nm by co-evaporation so that coumarin 6 is included in Alq ₃ at a ratio of 1% by weight. Formed.

Next, an electron transport layer is formed. As a material for forming the electron transport layer, various electron transport materials can be used. In this example, Alq ₃ was used and a film thickness of 10 nm was formed by a vapor deposition method.

Next, an electron injection layer is formed. Various electron-injecting materials can be used for the electron-injecting layer. In this example, Alq ₃ and lithium are used, so that lithium is contained in Alq ₃ at a ratio of 1% by weight. It formed with the film thickness of 30 nm by the vapor deposition method.

  In this manner, after forming a layer containing a light emitting substance formed by stacking the layer containing the composite material of the present invention, the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer, the second layer is formed. The electrode is formed by sputtering or vapor deposition. In this embodiment, the second electrode functions as a cathode. In this example, Al was formed by a vapor deposition method.

FIG. 38 shows the normalized luminance time change of the light emitting element manufactured in this example, and FIG. 39 shows the voltage time change. As a measuring method, the initial luminance was set to 3000 cd / m ² and a constant current was kept flowing, whereby the temporal change in luminance and the temporal change in voltage were measured.

  FIG. 38 indicates that the light-emitting element manufactured in this example has little decrease in luminance due to change over time. In addition, as shown in FIG. 39, the voltage increase with time of the light-emitting element manufactured in this example is small. Therefore, it can be seen that a light-emitting element using the composite material of the present invention has a long lifetime and high reliability.

  In this example, a light-emitting element using the composite material of the present invention will be described.

  First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. An indium tin oxide containing silicon oxide, which is a transparent conductive film, was used as a material, and an anode having an electrode size (2 mm × 2 mm) was formed by a sputtering method.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing downward, and PCzPCA1 and molybdenum oxide with a film thickness of 50 nm are formed by co-evaporation. A layer containing was formed. At this time, co-evaporation was performed so that the weight ratio of PCzPCA1 to molybdenum oxide was 4: 2.

  Next, a hole transport layer is formed of a material having excellent hole transport properties. As a material for forming the hole transport layer, various hole transport materials can be used. In this example, α-NPD was formed with a film thickness of 10 nm by a vapor deposition method.

Next, a light emitting layer is formed. Note that holes and electrons recombine in the light emitting layer to emit light. In this example, among the materials forming the light emitting layer, Alq _{3 as the} host material and coumarin 6 as the guest material were used, and the coumarin 6 was contained in Alq ₃ at a ratio of 1% by weight. It formed with the film thickness of 40 nm by the vapor deposition method.

Next, an electron transport layer is formed. As a material for forming the electron transport layer, various electron transport materials can be used. In this example, Alq ₃ was used and a film thickness of 10 nm was formed by a vapor deposition method.

Next, an electron injection layer is formed. Various electron-injecting materials can be used for the electron-injecting layer. In this example, Alq ₃ and lithium are used, so that lithium is contained in Alq ₃ at a ratio of 1% by weight. The film was formed with a thickness of 10 nm by a vapor deposition method.

  In this manner, after forming a layer containing a light emitting substance formed by stacking the layer containing the composite material of the present invention, the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer, the second layer is formed. The electrode is formed by sputtering or vapor deposition. In this embodiment, the second electrode functions as a cathode. In this example, Al was formed by a vapor deposition method. The light-emitting element manufactured in this example is referred to as element 1.

  In this example, a light-emitting element using the composite material of the present invention will be described.

  First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. An indium tin oxide containing silicon oxide, which is a transparent conductive film, was used as a material, and an anode having an electrode size (2 mm × 2 mm) was formed by a sputtering method.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing downward, and PCzPCN1 and molybdenum oxide are deposited with a film thickness of 50 nm by a co-evaporation method. A layer containing was formed. At this time, co-evaporation was performed so that the weight ratio of PCzPCN1 to molybdenum oxide was 4: 2.

  Next, a hole transport layer is formed of a material having excellent hole transport properties. As a material for forming the hole transport layer, various hole transport materials can be used. In this example, α-NPD was formed with a film thickness of 10 nm by a vapor deposition method.

Next, a light emitting layer is formed. Note that holes and electrons recombine in the light emitting layer to emit light. In this example, Alq _{3 as} a host material and coumarin 6 as a guest material are used, and the film thickness is 40 nm by co-evaporation so that coumarin 6 is included in Alq ₃ at a ratio of 1% by weight. Formed.

Next, an electron transport layer is formed. As a material for forming the electron transport layer, various electron transport materials can be used. In this example, Alq ₃ was used and a film thickness of 10 nm was formed by a vapor deposition method.

Next, an electron injection layer is formed. Various electron-injecting materials can be used for the electron-injecting layer. In this example, Alq ₃ and lithium are used, so that lithium is contained in Alq ₃ at a ratio of 1% by weight. The film was formed with a thickness of 10 nm by a vapor deposition method.

  In this manner, after forming a layer containing a light emitting substance formed by stacking the layer containing the composite material of the present invention, the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer, the second layer is formed. The electrode is formed by sputtering or vapor deposition. In this embodiment, the second electrode functions as a cathode. In this example, Al was formed by a vapor deposition method. The light-emitting element manufactured in this example is referred to as element 2.

  FIG. 43 shows the current-voltage characteristics, FIG. 44 shows the luminance-voltage characteristics, and FIG. 45 shows the current efficiency-luminance characteristics of the element 1 manufactured in Example 9 and the element 2 manufactured in Example 10.

  From FIG. 43, it can be seen that by using the composite material of the present invention for a light-emitting element, current easily flows. In addition, FIG. 44 shows that the driving voltage of the light emitting element is reduced. FIG. 45 shows that the light emission efficiency is high. This is presumably because the composite material of the present invention has high visible light transmittance and improved emission extraction efficiency. In addition, since the element 2 has improved carrier balance, it is considered that the light emission efficiency is further improved.

That is, it can be seen that by using the composite material of the present invention for a light-emitting element, a driving voltage for obtaining light emission with constant luminance can be reduced. Specifically, the voltage necessary for emitting light with a luminance of 1000 cd / m ² was 5.0 V in the element 1, and the current density at this time was 9.9 mA / cm ² . In addition, the voltage necessary for emitting light with a luminance of 1000 cd / m ² was 5.0 V in the element 2, and the current density at this time was 7.5 mA / cm ² . That is, it can be seen that low voltage driving and low current driving are possible by using the composite material of the present invention for a light emitting element.

  In this example, a light-emitting element using the composite material of the present invention will be described.

  First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. An indium tin oxide containing silicon oxide, which is a transparent conductive film, was used as a material, and an anode having an electrode size (2 mm × 2 mm) was formed by a sputtering method.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing downward, and PCzPCA1 and molybdenum oxide with a film thickness of 50 nm are formed by co-evaporation. A layer containing was formed. At this time, co-evaporation was performed so that the weight ratio of PCzPCA1 to molybdenum oxide was 4: 2.

  Next, a hole transport layer is formed of a material having excellent hole transport properties. As a material for forming the hole transport layer, various hole transport materials can be used. In this example, α-NPD was formed with a film thickness of 10 nm by a vapor deposition method.

Next, a light emitting layer is formed. Note that holes and electrons recombine in the light emitting layer to emit light. In this example, Alq _{3 as} a host material and coumarin 6 as a guest material are used, and the film thickness is 40 nm by co-evaporation so that coumarin 6 is included in Alq ₃ at a ratio of 1% by weight. Formed.

Next, an electron transport layer is formed. As a material for forming the electron transport layer, various electron transport materials can be used. In this example, Alq ₃ was used and a film thickness of 10 nm was formed by a vapor deposition method.

Next, an electron injection layer is formed. Various electron-injecting materials can be used for the electron-injecting layer. In this example, Alq ₃ and lithium are used, so that lithium is contained in Alq ₃ at a ratio of 1% by weight. The film was formed with a thickness of 10 nm by a vapor deposition method.

  Next, a layer containing PCzPCA1 and molybdenum oxide with a thickness of 20 nm was formed by a co-evaporation method. At this time, co-evaporation was performed so that the weight ratio of PCzPCA1 to molybdenum oxide was 4: 2.

  Thus, a layer containing a luminescent substance formed by laminating a layer containing the composite material of the present invention, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a layer containing the composite material of the present invention. After forming the second electrode, a second electrode is formed by a sputtering method or an evaporation method. In this embodiment, the second electrode functions as a cathode. In this example, Al was formed by a vapor deposition method. The light-emitting element manufactured in this example is referred to as an element 3.

  In this example, a light-emitting element using the composite material of the present invention will be described.

  First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. An indium tin oxide containing silicon oxide, which is a transparent conductive film, was used as a material, and an anode having an electrode size (2 mm × 2 mm) was formed by a sputtering method.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing downward, and PCzPCN1 and molybdenum oxide are deposited with a film thickness of 50 nm by a co-evaporation method. A layer containing was formed. At this time, co-evaporation was performed so that the weight ratio of PCzPCN1 to molybdenum oxide was 4: 2.

  Next, a hole transport layer is formed of a material having excellent hole transport properties. As a material for forming the hole transport layer, various hole transport materials can be used. In this example, α-NPD was formed with a film thickness of 10 nm by a vapor deposition method.

Next, a light emitting layer is formed. Note that holes and electrons recombine in the light emitting layer to emit light. In this example, Alq _{3 as} a host material and coumarin 6 as a guest material are used, and the film thickness is 40 nm by co-evaporation so that coumarin 6 is included in Alq ₃ at a ratio of 1% by weight. Formed.

Next, an electron transport layer is formed. As a material for forming the electron transport layer, various electron transport materials can be used. In this example, Alq ₃ was used and a film thickness of 10 nm was formed by a vapor deposition method.

Next, an electron injection layer is formed. Various electron-injecting materials can be used for the electron-injecting layer. In this example, Alq ₃ and lithium are used, so that lithium is contained in Alq ₃ at a ratio of 1% by weight. The film was formed with a thickness of 10 nm by a vapor deposition method.

  Next, a layer containing PCzPCN1 and molybdenum oxide with a thickness of 20 nm was formed by a co-evaporation method. At this time, co-evaporation was performed so that the weight ratio of PCzPCN1 to molybdenum oxide was 4: 2.

  Thus, a layer containing a luminescent substance formed by laminating a layer containing the composite material of the present invention, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a layer containing the composite material of the present invention. After forming the second electrode, a second electrode is formed by a sputtering method or an evaporation method. In this embodiment, the second electrode functions as a cathode. In this example, Al was formed by a vapor deposition method. The light-emitting element manufactured in this example is referred to as an element 4.

  FIG. 46 shows the current-voltage characteristics of the element 3 produced in Example 11 and the element 4 produced in Example 12, FIG. 47 shows the luminance-voltage characteristics, and FIG. 48 shows the current efficiency-luminance characteristics.

  From FIG. 46, it can be seen that a current easily flows by using the composite material of the present invention for a light-emitting element. In addition, FIG. 47 shows that the driving voltage of the light emitting element is reduced. FIG. 48 shows that the light emission efficiency is high. Since the composite material of the present invention has a high visible light transmittance, it is considered that the light extraction efficiency is improved.

That is, it can be seen that by using the composite material of the present invention for a light-emitting element, a driving voltage for obtaining light emission with constant luminance can be reduced. Specifically, the voltage necessary for emitting light with a luminance of 1000 cd / m ² was 5.6 V in the element 3, and the current density at this time was 9.7 mA / cm ² . In addition, the voltage required to emit light with a luminance of 1000 cd / m ² was 5.6 V in the element 4, and the current density at this time was 8.8 mA / cm ² . That is, it can be seen that low voltage driving and low current driving are possible by using the composite material of the present invention for a light emitting element.

  In this example, a vapor deposition apparatus for forming a layer containing the composite material of the present invention will be described. As an example of the vapor deposition apparatus, a perspective view is shown in FIG. The mechanism of the vapor deposition apparatus is briefly shown below.

  The substrate 701 is aligned with the vapor deposition mask 702 in advance, and the substrate is conveyed in the direction of the arrow 706 while being aligned. The substrate is transported and passes above the deposition shield 703a. The deposition shield 703a has an opening 703b, and the vapor deposition material from the vapor deposition source 704 is sublimated from the opening 703b. In order to maintain the sublimation direction (the direction of arrow 710) of the vapor deposition material from the opening 703b, the deposition shield 703a is heated so as not to adhere to the deposition shield itself.

The vapor deposition source 704 can be installed with a plurality of crucibles, and can further move in the direction of an arrow 705. As a vapor deposition method, a resistance heating method is used. Further, it is desirable that the range in which the vapor deposition source moves is wider than the width Wa of the substrate. Further, making the width Wb of the deposition shield wider than the width Wa of the substrate improves the film thickness uniformity of the deposited film.

That is, in the vapor deposition apparatus illustrated in FIG. 51A, the deposition shield is provided in the film formation chamber in order to maintain the sublimation direction of the vapor deposition material, and a plurality of openings are provided. Is a mechanism to sublimate. Below the deposition shield, an evaporation source that can move in a direction perpendicular to the moving direction (also referred to as a transport direction) of the substrate is provided. In addition, the width Wb of the deposition shield is made wider than the width Wa of the substrate to improve the film thickness uniformity of the deposited film.

  Note that there is no particular limitation on the shape and number of the opening 703b in the evaporation apparatus illustrated in FIG.

  In addition, an installation chamber connected to the film formation chamber via a gate may be provided in order to supply the evaporation material to the crucible of the evaporation source. A plurality of vapor deposition sources and deposition shields may be provided in one film formation chamber. FIG. 51B shows a top view of a vapor deposition apparatus provided with a plurality of vapor deposition sources and an installation chamber. When the installation chamber 707 is installed in the direction of movement of the vapor deposition source (the direction of the arrow 705) and the vapor deposition material is replenished, the vapor deposition source may be moved to the installation chamber for replenishment. When the vapor deposition source is fixed in the film formation chamber, the film formation chamber must be at atmospheric pressure in order to replenish the vapor deposition material with the vapor deposition material. It takes time to do. When the installation chamber 707 is provided, the deposition material can be replenished in a short time because only the installation chamber needs to be switched between the atmospheric pressure and the vacuum while the vacuum degree of the film formation chamber 700 is maintained.

Further, a second deposition shield 709 may be provided in parallel with the deposition shield 703a, and a second deposition source 708 that moves in a direction perpendicular to the substrate transport direction may be provided. By providing a plurality of vapor deposition sources in one film formation chamber, continuous stacked film formation is possible. Although an example in which two deposition sources are provided in one film formation chamber is shown here, a larger number of deposition sources may be provided in one film formation chamber.

  That is, two deposition shields may be provided in one film formation chamber in a direction perpendicular to the substrate transfer direction, and the same evaporation material may be continuously formed by providing an evaporation source for each. By using such a vapor deposition apparatus, the deposition rate can be increased. The two deposition shields are provided in parallel and have a sufficient interval.

Alternatively, different vapor deposition materials may be set in two vapor deposition sources to continuously form a laminated film. For example, the first organic compound (carbazole derivative) and the inorganic compound are separately set in two crucibles of the first vapor deposition source, and the substrate is passed over the first vapor deposition source, thereby causing the main substrate to pass through the substrate. A layer comprising the inventive composite is deposited. Next, the substrate is moved, the second organic compound is set in the crucible of the second evaporation source, and the substrate is passed over the second evaporation source to be on the layer containing the composite material of the present invention. A light emitting layer can be deposited.

  In this example, element characteristics of a plurality of light-emitting elements having different mixing ratios of an organic compound and an inorganic compound in a layer containing a composite material are shown in FIGS. The element structure of the light-emitting element manufactured in this example is as shown in Table 1.

  First, a method for manufacturing the light-emitting element manufactured in this example is described. First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. Using indium tin oxide containing silicon oxide, which is a transparent conductive film, as a material, a film was formed by a sputtering method to form a shape of 2 mm × 2 mm.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing down, and a composite material including PCzPCN1 and molybdenum oxide is formed by a co-evaporation method. The containing layer was formed with a film thickness of 50 nm.

  Subsequently, a hole transport layer is formed of a material having excellent hole transportability. As a material for forming the hole transport layer, various hole transport materials can be used, but in this example, α-NPD is used to form the hole transport layer by forming it to a thickness of 10 nm. did.

Thereafter, a light emitting layer is formed. In this light emitting layer, holes and electrons are recombined to obtain light emission. In this example, the light emitting layer was a host-guest type light emitting layer, Alq ₃ was used as the host material, and Coumarin 6 was used as the guest material. The film was formed by co-evaporation so that Alq ₃ and coumarin 6 were in a weight ratio of 1: 0.01, and the film thickness was 40 nm.

After forming the light emitting layer, an electron transport layer is subsequently formed. As the material for forming the electron transport layer, various electron transport materials can be used. In this example, Alq ₃ was used, and the film thickness was 40 nm.

  Next, an electron injection layer is formed. Various electron-injecting materials can be used for the electron-injecting layer. In this embodiment, lithium-fluoride was formed to a thickness of 1 nm.

  Finally, a second electrode is formed to manufacture the light-emitting element of this example. In this embodiment, the second electrode is formed by depositing Al by vapor deposition.

  Note that in this example, six types of light-emitting elements (elements 5 to 10) having different mixing ratios of the organic compound and the inorganic compound in the layer including the composite material were manufactured, and data thereof are shown in FIGS. The mixing ratio of each element (PCzPCN1: molybdenum oxide) is expressed by weight ratio, the element 5 is 4: 0.5, the element 6 is 4: 1, the element 7 is 4: 2, and the element 8 is 4: 3. Element 9 is 4: 4 and Element 10 is 4: 5.

  FIG. 52 shows current efficiency-luminance characteristics of the elements 5 to 10. From this, it was found that in the mixing ratio range of the composite material in the light-emitting element manufactured in this example, the smaller the amount of the inorganic compound in the layer containing the composite material, the better the current efficiency.

  FIG. 53 shows current-voltage characteristics of the elements 5 to 10. From this, it was found that in the mixing ratio range of the composite material in the light-emitting element manufactured in this example, the current-voltage characteristics are better as the amount of the inorganic compound in the layer containing the composite material is larger.

  FIG. 54 shows luminance-voltage characteristics of the elements 5 to 10. From this, it was found that in the mixing ratio range of the composite material in the light-emitting element manufactured in this example, all showed good luminance-voltage characteristics.

  FIG. 67 shows power efficiency-luminance characteristics of the elements 5 to 10 manufactured in this example. Higher power efficiency means lower power consumption. From FIG. 67, it was found that in the mixing ratio range of the composite material in the light-emitting element manufactured in this example, the smaller the amount of the inorganic compound in the layer containing the composite material, the better the power efficiency.

  In this example, a specific example of a layer including a carbazole derivative represented by the general formula (1) and an inorganic compound having an electron accepting property with respect to the carbazole derivative is illustrated. PCzPCN1 was used as the carbazole derivative, and molybdenum oxide was used as the inorganic compound.

  First, a glass substrate is fixed to a substrate holder in a vacuum deposition apparatus. Then, PCzPCN1 and molybdenum oxide (VI) were put in separate resistance heating evaporation sources, and a layer containing PCzPCN1 and molybdenum oxide was formed by co-evaporation under reduced pressure. At this time, co-evaporation was performed so that the weight ratio of PCzPCN1 to molybdenum oxide was 4: 2. The film thickness was 100 nm.

FIG. 55 shows the result of measuring the absorption spectrum of the PCzPCN1-molybdenum oxide composite film formed in this manner.

As can be seen from FIG. 55, the PCzPCN1-molybdenum oxide composite film showed a new absorption that was not seen in the PCzPCN1 single film (in the figure, it is a part surrounded by a broken line and has a peak near 1120 nm). . This is because PCzPCN1 and molybdenum oxide exchange electrons, and it is considered that molybdenum oxide receives electrons from PCzPCN1 and holes are generated in PCzPCN1.

  Therefore, in the PCzPCN1-molybdenum oxide composite film formed in this embodiment, carriers are generated internally, and the driving voltage of the light-emitting element can be reduced.

  As shown in FIG. 55, in the PCzPCN1-molybdenum oxide composite film, no significant absorption was observed in the visible light region (400 nm to 700 nm).

  Next, the visible light transmittance of the composite film fabricated in Example 15 is shown in FIG.

  FIG. 56 shows a diagram in which the vertical axis in FIG. 55 is converted from absorbance to transmittance. In FIG. 56, the wavelength on the horizontal axis is limited to the visible light region (400 nm to 700 nm). As shown in FIG. 56, the transmittance in the visible light region of the PCzPCN1-molybdenum oxide composite film produced in Example 15 is about 90%.

In addition, FIG. 72 shows the absorbance per 1 μm in blue (450 nm) to red (650 nm) of the PCzPCN1-molybdenum oxide composite film produced in Example 15. As can be seen from FIG. 72, the absorbance per 1 μm of the composite material of the present invention is 2 (μm) ⁻¹ or less in all cases, and the absorbance is small from blue (450 nm) to red (650 nm). Therefore, the composite material of the present invention has high translucency over blue (450 nm), green (520 nm), and red (650 nm), and is suitable for a full color display.

  From the above, it was found that the composite material of the present invention was superior in visible light transmissivity compared to conventional composite materials.

  In this example, the current-voltage characteristics of the layer containing the composite material of the present invention were measured.

  First, indium tin oxide containing silicon oxide (ITSO) was formed over a glass substrate by a sputtering method to form a first electrode. The electrode size 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 decompressed, and then PCzPCN1 and molybdenum oxide (VI) were co-evaporated on the first electrode to form a layer made of the composite material of the present invention. The film thickness was 200 nm. 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 ratio of PCzPCN1 to molybdenum oxide (VI) was adjusted to be 4: 2 by weight.

A light emitting element of the present invention was manufactured by forming a second electrode by depositing aluminum (Al) on the layer containing the composite material of the present invention by vapor deposition by resistance heating.

The current-voltage characteristics were measured by the two-terminal method with ITSO as the anode and Al as the cathode as the forward direction, and ITSO as the cathode and Al as the anode as the reverse direction.

FIG. 57 shows the results of current-voltage characteristics at room temperature (25 ° C.). In the device manufactured in this example, current flows in both the forward and reverse directions, and it can be seen that the current-voltage characteristics are symmetrical about the origin. It is considered that the interface between the electrode and the layer containing the composite material of the present invention is not a Schottky contact because it has symmetry despite using electrodes different from ITSO and Al.

  In this example, a light-emitting element having a layer containing a composite material was manufactured, and the influence of the mixing ratio of an organic compound and an inorganic compound on the light-emitting characteristics of the element was examined. The results are shown in FIGS. The element structure of the light-emitting element manufactured in this example is as shown in Table 2.

  First, a method for manufacturing the light-emitting element manufactured in this example is described. First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. A film was formed by a sputtering method using indium tin oxide containing silicon oxide as a transparent conductive film as an electrode material.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing down, and a composite material including PCzPCN1 and molybdenum oxide is formed by a co-evaporation method. The containing layer was formed with a thickness of 120 nm.

  Subsequently, a hole transport layer is formed of a material having excellent hole transportability. As a material for forming the hole transport layer, various hole transport materials can be used, but in this example, α-NPD is used to form the hole transport layer by forming it to a thickness of 10 nm. did.

Thereafter, a light emitting layer is formed. In this light emitting layer, holes and electrons are recombined to obtain light emission. In this embodiment mode, the light emitting layer is a host-guest type light emitting layer, Alq ₃ is used as the host material, and Coumarin 6 is used as the guest material. The film was formed by co-evaporation so that Alq ₃ and coumarin 6 were in a weight ratio of 1: 0.01, and the film thickness was 40 nm.

After forming the light emitting layer, an electron transport layer is subsequently formed. As a material for forming the electron transport layer, various electron transport materials can be used. In this example, Alq ₃ was used, and the film was formed by vapor deposition so that the film thickness was 30 nm.

  Next, an electron injection layer is formed. Various electron-injecting materials can be used for the electron-injecting layer. In this embodiment, lithium-fluoride was formed to a thickness of 1 nm.

  Finally, a second electrode is formed to manufacture the light-emitting element of this example. In this example, the second electrode was formed by depositing Al with a thickness of 200 nm by vapor deposition.

  Note that in this example, three types of light-emitting elements (elements 11 to 13) having different mixing ratios of the organic compound and the inorganic compound in the layer including the composite material were manufactured, and data thereof are shown in FIGS. Note that the mixing ratio (PCzPCN1: molybdenum oxide) of each element is expressed by a weight ratio, and the element 11 is 4: 0.5, the element 12 is 4: 1, and the element 13 is 4: 2.

  FIG. 58 shows current-voltage characteristics of the elements 11 to 13. From FIG. 58, it was found that in the mixing ratio range of the composite material in the light-emitting element manufactured in this example, the current-voltage characteristics are better as the amount of the inorganic compound in the layer containing the composite material is larger.

  FIG. 59 shows current efficiency-luminance characteristics of the elements 11 to 13. From FIG. 59, it can be seen that in the mixing ratio range of the composite material in the light-emitting element manufactured in this example, good current efficiency-luminance characteristics are exhibited.

  FIG. 60 shows luminance-voltage characteristics of the elements 11 to 13. From FIG. 60, it was found that in the mixing ratio range of the composite material in the light-emitting element manufactured in this example, the luminance-voltage characteristics are better as the amount of the inorganic compound in the layer including the composite material is larger.

  In this example, a light-emitting element using the composite material of the present invention will be described.

  First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. An anode was formed by sputtering using indium tin oxide containing silicon oxide, which is a transparent conductive film.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing down, and PCzPCN1 and molybdenum oxide are deposited with a film thickness of 120 nm by a co-evaporation method. A layer containing was formed. At this time, co-evaporation was performed so that the weight ratio of PCzPCN1 to molybdenum oxide was 4: 2.

  Next, a hole transport layer is formed of a material having excellent hole transport properties. As a material for forming the hole transport layer, various hole transport materials can be used. In this example, α-NPD was formed with a film thickness of 10 nm by a vapor deposition method.

Next, a light emitting layer is formed. Note that holes and electrons recombine in the light emitting layer to emit light. In this example, Alq _{3 as} a host material and coumarin 6 as a guest material are used, and a 37.5 nm film is formed by co-evaporation so that coumarin 6 is contained in Alq ₃ at a ratio of 1% by weight. Formed with thickness.

Next, an electron transport layer is formed. As a material for forming the electron transport layer, various electron transport materials can be used. In this example, Alq ₃ was used and formed by a vapor deposition method with a film thickness of 37.5 nm.

  Next, an electron injection layer is formed. Various electron-injecting materials can be used for the electron-injecting layer. In this embodiment, lithium-fluoride was formed to a thickness of 1 nm.

  Finally, a second electrode is formed to manufacture the light-emitting element of this example. In this example, the second electrode was formed by depositing Al with a thickness of 200 nm by vapor deposition. The light-emitting element manufactured in this example is referred to as an element 14.

  61 shows current-voltage characteristics, current efficiency-luminance characteristics are shown in FIG. 62, and luminance-voltage characteristics are shown in FIG. 63.

  As shown in FIGS. 61 to 63, it can be seen that the element 14 manufactured in this example is excellent in current-voltage characteristics, current efficiency-luminance characteristics, and luminance-voltage characteristics. This is partly due to the fact that the layer containing the composite material of the present invention does not have a large absorption peak in the visible region. In addition, since the layer including the composite material of the present invention has high conductivity, it exhibits good current-voltage characteristics.

That is, it can be seen that by using the composite material of the present invention for a light-emitting element, a driving voltage for obtaining light emission with constant luminance can be reduced. Specifically, the voltage necessary for emitting light with a luminance of 1000 cd / m ² was 5.8 V in the element 14, and the current density at this time was 8.5 mA / cm ² . That is, it can be seen that low voltage driving and low current driving are possible by using the composite material of the present invention for a light emitting element.

  In addition, FIG. 64 shows power efficiency-luminance characteristics of the element 14 manufactured in this example. Higher power efficiency means lower power consumption, and FIG. 64 shows that the light-emitting element of the present invention shows good power efficiency.

FIG. 65 shows the change over time of the normalized luminance of the element 14 produced in this example. The measurement was performed by setting the initial luminance to 3000 cd / m ² , energizing under constant current conditions at room temperature, and monitoring the temporal change in luminance and the temporal change in voltage.

  FIG. 65 shows that the light-emitting element manufactured in this example has little decrease in luminance due to change over time. Therefore, it can be seen that a light-emitting element using the composite material of the present invention has a long lifetime and high reliability.

  In this example, a light-emitting element using the composite material of the present invention will be described.

  First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. An indium tin oxide containing silicon oxide, which is a transparent conductive film, was used as an electrode material, and an anode was formed by a sputtering method.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing down, and a composite material including PCzPCN1 and molybdenum oxide is formed by a co-evaporation method. The containing layer was formed with a thickness of 120 nm.

  Next, a hole transport layer is formed of a material having excellent hole transport properties. As a material for forming the hole transport layer, various hole transport materials can be used. In this example, α-NPD was formed with a film thickness of 10 nm by a vapor deposition method.

Next, a light emitting layer is formed. Note that holes and electrons recombine in the light emitting layer to emit light. In this example, Alq _{3 as} a host material and coumarin 6 as a guest material are used, and a 37.5 nm film is formed by co-evaporation so that coumarin 6 is contained in Alq ₃ at a ratio of 1% by weight. Formed with thickness.

Next, an electron transport layer is formed. As a material for forming the electron transport layer, various electron transport materials can be used. In this example, Alq ₃ was used and formed by a vapor deposition method with a film thickness of 37.5 nm.

  Next, an electron injection layer is formed. Various electron-injecting materials can be used for the electron-injecting layer. In this embodiment, lithium-fluoride was formed to a thickness of 1 nm.

  In this manner, after forming a layer containing a light emitting substance formed by stacking the layer containing the composite material of the present invention, the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer, the second layer is formed. The electrode is formed by sputtering or vapor deposition. In this embodiment, the second electrode functions as a cathode. In this embodiment, Al is formed with a film thickness of 200 nm by a vapor deposition method.

  Note that in this example, two types of light-emitting elements (elements 15 to 16) having different mixing ratios of the organic compound and the inorganic compound in the layer including the composite material are manufactured and data thereof are shown. Note that the mixing ratio (PCzPCN1: molybdenum oxide) of each element is shown by weight ratio, and the element 15 is 4: 1 and the element 16 is 4: 2.

FIG. 66 shows changes in normalized luminance time of the element 15 and the element 16 manufactured in this example. The measurement method was performed by setting the initial luminance to 3000 cd / m ² , energizing at 60 ° C. under constant current conditions, and measuring the temporal change in luminance and the temporal change in voltage.

  FIG. 66 shows that the light-emitting element manufactured in this example shows little decrease in luminance due to change over time. In particular, the element 15 having a low concentration of molybdenum oxide is less susceptible to a decrease in luminance due to changes with time. Therefore, it can be seen that a light-emitting element using the composite material of the present invention has a long lifetime and high reliability.

  In this example, the electronic state of the layer containing the composite material of the present invention was measured.

  A layer containing PCzPCA1 and molybdenum oxide was formed on the quartz substrate by a co-evaporation method so as to have a thickness of 200 nm. At this time, co-evaporation was performed so that the weight ratio of PCzPCA1 to molybdenum oxide was 1: 0.5. ESR (Electron Spin Resonance) measurement of the layer containing PCzPCA1 and molybdenum oxide was performed. The results are shown in FIG. ESR measurement is a measurement using a resonance absorption transition of microwaves, which is a Zeeman splitting of the energy level of the unpaired electron by applying a strong magnetic field to a sample having unpaired electrons, and the energy difference between the levels. Is the method. In this ESR measurement, the presence / absence of unpaired electrons and the spin state can be determined by measuring the frequency at which absorption occurs and the strength of the magnetic field. Further, the electron spin concentration can be obtained from the absorption intensity. The measurement uses an electron spin resonance analyzer, JES-TE200 (manufactured by JEOL Ltd.), resonance frequency 9.3 GHz, modulation frequency 100 kHz, modulation width 0.63 mT, amplification factor 50, time constant 0.1 sec, microwave input The measurement was performed under the conditions of 1 mW, sweep time 4 min, and measurement temperature at room temperature. Note that manganese supported on magnesium oxide was used as a magnetic field calibration sample. As a comparative example, ESR measurement was also performed on a PCzPCA1 single film (thickness 200 nm) and a molybdenum oxide single film (thickness 200 nm). FIG. 69 shows the ESR measurement result of the PCzPCA1 single film, and FIG. 70 shows the ESR measurement result of the molybdenum oxide single film.

68 to 70, no ESR signal was detected in the PCzPCA1 single film and the molybdenum oxide single film, but an ESR signal was detected in the layer containing PCzPCA1 and molybdenum oxide. This indicates that the layer containing PCzPCA1 and molybdenum oxide has unpaired electrons and is in an electronic state different from that of the PCzPCA1 single film and the molybdenum oxide single film not having unpaired electrons. It was. Note that FIG. 68 shows that the g value of the layer containing PCzPCA1 and molybdenum oxide is 2.0024, which is very close to the free electron g value of 2.0023. On the other hand, the line width was as narrow as 0.67 mT, and the spin concentration was found to be 3.4 × 10 ²⁰ spins / cm ³ .

  In this example, 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino]-represented by the structural formula (12) was synthesized by a synthesis method different from the synthesis method shown in Example 1. A method for synthesizing 9-phenylcarbazole (abbreviation: PCzPCA1) will be described. The synthesis scheme is shown in (D-1).

  3-iodo-9-phenylcarbazole 1.60 mg (4.33 mmol), copper (I) iodide 19.0 mg (0.1 mmol), tert-butoxypotassium 1.10 g (10 mmol), tri-n-butylphosphine ( 0.2 mol / L dehydrated hexane solution) 1.0 mL was put into a 200 mL three-necked flask, and the atmosphere in the flask was replaced with nitrogen. 10 mL of xylene and 0.2 mL (2.1 mmol, 195.6 mg) of aniline were added, and 6 ° C was added at 135 ° C. Reflux for hours. After the reaction solution was cooled to room temperature, 100 mL of toluene was added through Florisil and Celite, followed by filtration. The obtained filtrate was washed twice with water, the aqueous layer was extracted twice with toluene, the extracted solution was combined with the organic layer, washed with saturated brine, and dried over magnesium sulfate. The solution was naturally filtered, and the compound obtained by concentrating the filtrate was subjected to silica gel chromatography (a mixed solution of toluene and hexane) to obtain the desired product. 140 mg of a pale yellow solid was obtained in a yield of 21%.

  By using the synthesis method shown in this example, the carbazole derivative of the present invention can be obtained by a one-step reaction.

  In this example, 3- [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) represented by the structural formula (17) was synthesized by a synthesis method different from the synthesis method shown in Example 3. ) A method for synthesizing amino] -9-phenylcarbazole (abbreviation: PCzPCN1) will be described. The synthesis scheme is shown in (D-2).

  3-Iodo-9-phenylcarbazole 3.69 g (0.01 mol), 1-naphthylamine 716 mg (5 mmol), copper iodide 385 mg (2 mmol), potassium carbonate 2.74 g (0.02 mol), 18-crown-6 771 mg (0.02 mol) of ether was placed in a 200 mL three-neck flask, the atmosphere in the flask was replaced with nitrogen, 8 mL of DMPU was added, and the mixture was stirred at 170 ° C. for 24 hours. The reaction solution is cooled to room temperature, washed twice with water, and then the aqueous layer is extracted twice with toluene. The extracted solution is washed with the previously washed organic layer, washed with saturated brine, and dried over magnesium sulfate. did. The solution was naturally filtered, and the resulting compound was purified by silica gel column chromatography (hexane: toluene = 7: 3). As a result, 1.52 g of the target pale yellow solid was obtained in a yield of 48%. Obtained.

  By using the synthesis method shown in this example, the carbazole derivative of the present invention can be obtained by a one-step reaction.

  As an example of the carbazole derivative of the present invention, 3- {N- [9- (4-biphenylyl) carbazol-3-yl] -N-phenylamino} -9- (4-biphenylyl) represented by the structural formula (70) A method for synthesizing carbazole (abbreviation: BCzBCA1) will be described.

[Step 1]
First, a method for synthesizing 9- (4-biphenylyl) carbazole will be described. A synthesis scheme of 9- (4-biphenylyl) carbazole is shown in (B-1).

  In a three-necked flask, 12 g (50 mmol) of 4-bromobiphenyl, 8.4 g (50 mmol) of carbazole, 230 mg (1 mmol) of palladium acetate, 1.8 g (3.0 mmol) of 1,1-bis (diphenylphosphino) ferrocene, After adding 13 g (180 mmol) of sodium-tert-butoxide and replacing the atmosphere in the flask with nitrogen, 80 mL of dehydrated xylene was added for deaeration. This was heated and stirred under a nitrogen atmosphere at 120 ° C. for 7.5 hours. After completion of the reaction, about 600 mL of warm toluene was added to this suspension, and this was filtered twice through Florisil, alumina, and celite. The obtained filtrate was concentrated and recrystallized by adding hexane. This was filtered, and the residue was collected and dried to obtain 14 g of cream powder 9- (4-biphenylyl) carbazole in a yield of 87%.

[Step 2]
Next, a method for synthesizing 3-bromo-9- (4-biphenylyl) carbazole will be described. A synthesis scheme of 3-bromo-9- (4-biphenylyl) carbazole is shown in (B-2).

  9- (4-biphenylyl) carbazole (3.1 g, 10 mmol) was dissolved in chloroform (100 mL), and N-bromosuccinimide (1.8 g, 10 mmol) was slowly added thereto. This was stirred overnight (about 24 hours) and then washed with water. Magnesium sulfate was added to this to remove moisture, and filtration was performed to obtain a filtrate. This was concentrated, recovered and dried. A beige powder of 3-bromo-9- (4-biphenylyl) carbazole (3.7 g) was obtained in a yield of 95%.

[Step 3]
Next, a method for synthesizing 9- (4-biphenylyl) -3-iodo-carbazole will be described. A synthesis scheme of 9- (4-biphenylyl) -3-iodo-carbazole is shown in (B-3).

  9- (4-biphenylyl) carbazole (3.2 g, 10 mmol) was dissolved in a mixture of glacial acetic acid (200 mL), toluene (200 mL), and ethyl acetate (50 mL), and N-iodosuccinimide (2.3 g, 10 mmol) was slowly added thereto. This was stirred overnight (about 24 hours), and then washed with water, an aqueous sodium thiosulfate solution, and saturated brine. Magnesium sulfate was added to this to remove moisture, and filtration was performed to obtain a filtrate. This was concentrated, acetone and hexane were added, and ultrasonic waves were applied for recrystallization. This was filtered, and the filtrate was collected and dried. 4.4 g of 9- (4-biphenylyl) -3-iodo-carbazole as a beige powder was obtained in a yield of 98%.

[Step 4]
Next, a method for synthesizing 9-[(4-biphenylyl) carbazol-3-yl] -N-phenylamine (abbreviation: BCA) will be described. A synthesis scheme of BCA is shown in (B-4).

  In a three-necked flask, 3.7 g (9.2 mmol) of 3-bromo-9- (4-biphenylyl) carbazole, 63 mg (0.3 mmol) of palladium acetate, 330 mg of 1,1-bis (diphenylphosphino) ferrocene 1.6 mmol), 1.5 g (15 mmol) of sodium-tert-butoxide was added, the atmosphere in the flask was replaced with nitrogen, 20 mL of dehydrated xylene was added and deaerated, and then 9.3 g (10 mmol) of aniline was added. . This was heated and stirred at 130 ° C. for 4 hours under a nitrogen atmosphere. After completion of the reaction, about 300 mL of warm toluene was added to this suspension, and this was filtered through Florisil, alumina, and celite. The obtained filtrate was concentrated, hexane was added, and the mixture was ultrasonically precipitated. This was filtered, and the residue was dried to obtain 3.5 g of a cream powder 9-[(4-biphenylyl) carbazol-3-yl] -N-phenylamine (BCA) in a yield of 93%. .

[Step 5]
Next, a method for synthesizing 3- {N- [9- (4-biphenylyl) carbazol-3-yl] -N-phenylamino} -9- (4-biphenylyl) carbazole (abbreviation: BCzBCA1) will be described. A synthesis scheme of BCzBCA1 is shown in (B-5).

In a three-necked flask, 3.5 g (7.9 mmol) of 9- (4-biphenylyl) -3-iodo-carbazole and 3.3 g of 9-[(4-biphenylyl) carbazol-3-yl] -N-phenylamine (8.0 mmol), 230 mg (0.4 mmol) of bis (dibenzylideneacetone) palladium (0) and 1.2 g (12 mmol) of sodium-tert-butoxide were added, and the atmosphere in the flask was replaced with nitrogen, followed by dehydration. Deaeration was performed by adding 30 mL of xylene. To this was added 1.4 mL (1.2 mmol) of a 10 wt% hexane solution of tri-tert-butylphosphine, and the mixture was heated and stirred at 110 ° C. for 3 hours in a nitrogen atmosphere. After completion of the reaction, about 500 mL of warm toluene was added to this suspension, and this was filtered through Florisil, alumina, and celite. The obtained filtrate was concentrated and the target product was obtained by silica gel column chromatography (toluene: hexane = 1: 1). This was concentrated, hexane was added, and ultrasonic waves were applied for precipitation. 1.1 g of cream powder 3- {N- [9- (4-biphenylyl) carbazol-3-yl] -N-phenylamino} -9- (4-biphenylyl) carbazole (abbreviation: BCzBCA1), yield Obtained at 19%. ^{The 1} H-NMR data is shown below. ¹ H-NMR (300 MHz, DMSO-d): δ = 6.86 (t, J = 7.2, 1H), 6.94 (d, J = 7.8, 2H), 7.18-7. 24 (m, 4H), 7.30 (dd, J = 8.9, 1.8, 2H), 7.41-7.54 (m, 12H), 7.70 (d, J = 8.4 4H), 7.77 (d, J = 7.2, 4H), 7.94 (d, J = 8.4, 4H), 8.06 (d, J = 2.1, 2H), 8 .12 (d, J = 7.8, 2H). A chart of ¹ H-NMR is shown in FIG. FIG. 73B shows an enlarged view of the 6.0 to 9.0 ppm portion in FIG. The ¹³ C-NMR data is shown below. (75.5 MHz, DMSO-d): δ = 109.6, 110.7, 117.4, 119.4, 119.7, 119.8, 120.5, 120.5, 122.4, 123. 7, 125.0, 126.2, 126.5, 126.8, 127.5, 128.1, 128.8, 136.0, 136.9, 139.1, 139.1, 140.6, 140.8, 149.3. A ¹³ C-NMR chart is shown in FIG. 74. FIG. 74B shows an enlarged view of the 6.0-9.0 ppm portion in FIG.

  Thermogravimetry-differential thermal analysis (TG-DTA) of the obtained BCzBCA1 was performed in the same manner as in Examples 1 to 3. For the measurement, a thermophysical property was evaluated at a temperature increase rate of 10 ° C./min in a nitrogen atmosphere using a differential thermothermal gravimetric simultaneous measurement device (Seiko Denshi Kogyo Co., Ltd., TG / DTA 320 type). As a result, from the relationship between weight and temperature (thermogravimetry), the temperature at which the weight was 95% or less with respect to the weight at the start of measurement under normal pressure was 425 ° C.

Moreover, the glass transition point (Tg) was measured using the differential scanning calorimetry apparatus (DSC) (the Perkin-Elmer company make, PyRis1). First, the sample was heated from −10 ° C. to 400 ° C. at 40 ° C./min, and then cooled to −10 ° C. at 40 ° C./min. Thereafter, the DSC chart of FIG. 75 was obtained by raising the temperature to 400 ° C. at 10 ° C./min. From this chart, it was found that the glass transition point (Tg) of BCzBCA1 was 137 ° C. From this, it was found that BCzBCA1 has a high glass transition point. In this measurement, no endothermic peak indicating the melting point was observed.

  Further, FIG. 76 shows an absorption spectrum of a toluene solution of BCzBCA1. For the measurement, an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550) was used. The solution was put in a quartz cell to prepare a sample, and the absorption spectrum obtained by subtracting the absorption spectrum of quartz is shown in FIG. In FIG. 76, the horizontal axis represents wavelength (nm) and the vertical axis represents absorption intensity (arbitrary unit). In the case of a toluene solution of BCzBCA1, the maximum absorption wavelength was 395 nm. An emission spectrum of a toluene solution of BCzBCA1 is shown in FIG. In FIG. 77, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). In the case of a toluene solution of BCzBCA1, the maximum emission wavelength was 434 nm (excitation wavelength: 323 nm).

  In addition, FIG. 78 shows an absorption spectrum of a thin film of BCzBCA1. For the measurement, an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550) was used. The thin film was deposited on a quartz substrate to prepare a sample, and the absorption spectrum obtained by subtracting the absorption spectrum of quartz is shown in FIG. In FIG. 78, the horizontal axis represents wavelength (nm) and the vertical axis represents absorption intensity (arbitrary unit). The maximum absorption wavelength was 318 nm in the case of the BCzBCA1 thin film. In addition, FIG. 79 shows an emission spectrum of the thin film of BCzBCA1. In FIG. 79, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). The maximum emission wavelength was 445 nm (excitation wavelength: 318 nm) in the case of a thin film of BCzBCA1.

  Further, the HOMO level and the LUMO level in the thin film state of BCzBCA1 were measured. The value of the HOMO level was obtained by converting the ionization potential value measured using a photoelectron spectrometer (AC-2, manufactured by Riken Keiki Co., Ltd.) into a negative value. The LUMO level value was obtained by using the absorption edge of the thin film in FIG. 78 as an energy gap and adding it to the HOMO level value. As a result, the HOMO level and the LUMO level were −5.14 eV and −2.04 eV, respectively.

  As an example of the carbazole derivative of the present invention, 3,6-bis [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9- (4 represented by the structural formula (71) A method for synthesizing -biphenylyl) carbazole (abbreviation: BCzPCN2) will be described.

[Step 1]
First, a method for synthesizing 9- (4-biphenylyl) -3,6-dibromo-carbazole will be described. A synthesis scheme of 9- (4-biphenylyl) -3,6-dibromo-carbazole is shown in (C-1).

9.6 g (30 mmol) of 9- (4-biphenylyl) carbazole was dissolved in a mixed solution of 250 mL of toluene, 250 mL of ethyl acetate, and 50 mL of glacial acetic acid, and 13 g (75 mmol) of N-bromosuccinimide was slowly added thereto. This was stirred for 5 days (about 100 hours), then washed with water and an aqueous sodium thiosulfate solution, neutralized with an aqueous sodium hydroxide solution, and washed again with water. Magnesium sulfate was added to this to remove moisture, and filtration was performed to obtain a filtrate. This was concentrated, recovered and dried. 15 g of 9- (4-biphenylyl) -3,6-dibromo-carbazole as a beige powder was obtained in a yield of 100%. The NMR data is shown below. ¹ H-NMR (300 MHz, CDCl ₃ -d): δ = 7.29 (d, J = 8.7, 2H), 7.40 (t, J = 7.5, 1H), 7.47-7 .56 (m, 6H), 7.67 (d, J = 7.5, 2H), 7.81 (d, J = 8.4, 2H), 8.20 (d, J = 2.1, 2H). A ¹ H-NMR chart is shown in FIG. FIG. 80B shows an enlarged view of the 6.0 to 9.0 ppm portion in FIG. The ¹³ C-NMR data is shown below. ¹³ C-NMR (75.5 MHz, CDCl ₃ -d): δ = 11.6, 113.3, 123.3, 123.3, 124.2, 127.2, 127.3, 127.9, 128 .8, 129.0, 129.5, 136.1, 140.1, 141.3. FIG. 81 shows a ¹³ C-NMR chart. FIG. 81B shows an enlarged view of the portion of 100 to 150 ppm in FIG.

[Step 2]
Next, a method for synthesizing 3,6-bis [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9- (4-biphenylyl) carbazole (abbreviation BCzPCN2) will be described. . A synthesis scheme of BCzPCN2 is shown in (C-2).

In a three-necked flask, 2.4 g (5.0 mmol) of 9- (4-biphenylyl) -3,6-dibromo-carbazole, 3.8 g (10 mmol) of PCN, and 580 mg of bis (dibenzylideneacetone) palladium (0). (1.0 mmol), tri-tert-butylphosphine 10 wt% hexane solution 6.0 mL (3 mmol) and sodium-tert-butoxide 3.0 g (30 mmol) were added, and the atmosphere in the flask was replaced with nitrogen. Deaeration was performed by adding 10 mL. This was heated and stirred at 130 ° C. for 12 hours in a nitrogen atmosphere. After completion of the reaction, about 550 mL of warm toluene was added to this suspension, and this was filtered through Florisil, alumina, and celite. The obtained filtrate was concentrated and the target product was obtained by silica gel column chromatography (toluene: hexane = 2: 1). This was concentrated, hexane was added, and ultrasonic waves were applied for precipitation. 2.7 g of lemon powder 3,6-bis [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9- (4-biphenylyl) carbazole (abbreviation: BCzPCN2) , Yield 51%. The NMR data is shown below. ¹ H-NMR (300 MHz, DMSO-d): δ = 6.88-7.67 (m, 45H), 7.76-7.79 (d, J = 7.8, 4H), 7.84- 7.86 (d, J = 7.8, 2H), 7.97-7.99 (d, J = 7.8, 2H). In addition, FIG. 82 shows a ¹ H-NMR chart. FIG. 82B shows an enlarged view of the 6.0-9.0 ppm portion in FIG. The ¹³ C-NMR data is shown below. ¹³ C-NMR (75.5 MHz, DMSO-d): δ = 109.3, 110.1, 110.5, 113.3, 113.3, 114.5, 114.6, 119.4, 120. 2, 122.0, 122.2, 123.1, 123.2, 123.3, 124.0, 124.7, 125.2, 125.6, 125.9, 126.2, 126.4, 126.5, 127.1, 127.4, 127.9, 128.1, 128.7, 129.7, 129.8, 134.8, 135.8, 136.1, 136.7, 136. 8, 138.8, 139.0, 140.4, 142.9, 143.3, 144.8. In addition, FIG. 83 shows a ¹³ C-NMR chart. FIG. 83B shows an enlarged view of the portion of 100 to 150 ppm in FIG.

  Thermogravimetry-differential thermal analysis (TG-DTA) of the obtained BCzPCN2 was performed in the same manner as in Examples 1 to 4. For the measurement, a thermophysical property was evaluated at a temperature increase rate of 10 ° C./min in a nitrogen atmosphere using a differential thermothermal gravimetric simultaneous measurement device (Seiko Denshi Kogyo Co., Ltd., TG / DTA 320 type). As a result, from the relationship between weight and temperature (thermogravimetry), the temperature at which the weight was 95% or less with respect to the weight at the start of measurement under normal pressure was 500 ° C. or higher.

Moreover, the glass transition point (Tg) was measured using the differential scanning calorimetry apparatus (DSC) (the Perkin-Elmer company make, PyRis1). First, the sample was heated from −10 ° C. to 400 ° C. at 40 ° C./min, and then cooled to −10 ° C. at 40 ° C./min. Thereafter, the DSC chart of FIG. 84 was obtained by raising the temperature to 400 ° C. at 10 ° C./min. From this chart, it was found that the glass transition point (Tg) of BCzPCN2 was 185 ° C. From this, it was found that BCzPCN2 has a high glass transition point. In this measurement, no endothermic peak indicating the melting point was observed.

  In addition, FIG. 85 shows an absorption spectrum of a toluene solution of BCzPCN2. For the measurement, an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550) was used. The solution was put in a quartz cell to prepare a sample, and an absorption spectrum obtained by subtracting the absorption spectrum of quartz is shown in FIG. In FIG. 85, the horizontal axis represents wavelength (nm) and the vertical axis represents absorption intensity (arbitrary unit). The maximum absorption wavelength was 370 nm in the case of BCzPCN2 toluene solution. In addition, an emission spectrum of a toluene solution of BCzPCN2 is shown in FIG. In FIG. 86, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). In the case of the BCzPCN2 toluene solution, the maximum emission wavelength was 465 nm (excitation wavelength: 320 nm).

  In this example, a light-emitting element using the composite material of the present invention will be described.

  First, a first electrode of a light emitting element is formed over a substrate. In this embodiment, the first electrode functions as an anode. An anode was formed by sputtering using indium tin oxide containing silicon oxide, which is a transparent conductive film.

  Next, the substrate on which the first electrode is formed is fixed to the substrate holder of the vacuum evaporation apparatus with the surface on which the first electrode is formed facing downward, and BCzBCA1 and molybdenum oxide are formed to a thickness of 50 nm by a co-evaporation method. A layer containing was formed. At this time, co-evaporation was performed so that the ratio of BCzBCA1 to molybdenum oxide was 4: 1 (= BCzBCA1: molybdenum oxide) by weight.

  Next, a hole transport layer is formed of a material having excellent hole transport properties. As a material for forming the hole transport layer, various hole transport materials can be used. In this example, α-NPD was formed with a film thickness of 10 nm by a vapor deposition method.

Next, a light emitting layer is formed. Note that holes and electrons recombine in the light emitting layer to emit light. In this example, Alq _{3 serving as} a host material and coumarin 6 serving as a guest material are used, and 40 nm of 40 nm is formed by a co-evaporation method so that the weight ratio is 1: 0.01 (= Alq ₃ : coumarin 6). It was formed with a film thickness.

Next, an electron transport layer is formed. In this example, Alq ₃ was used and was formed by a vapor deposition method with a film thickness of 10 nm.

Next, an electron injection layer is formed. In this example, Alq ₃ and lithium were adjusted to have a weight ratio of 1: 0.01 (= Alq ₃ : lithium), and a film was formed to a thickness of 20 nm.

  Finally, a second electrode is formed to manufacture the light-emitting element of this example. In this example, the second electrode was formed by depositing Al with a thickness of 200 nm by vapor deposition. The light-emitting element manufactured in this example is referred to as an element 17.

  FIG. 87 shows the current-voltage characteristics of the element 17 manufactured in this example, FIG. 88 shows the current efficiency-luminance characteristics, and FIG. 89 shows the luminance-voltage characteristics.

  As shown in FIGS. 87 to 89, it can be seen that the element 17 manufactured in this example has excellent current-voltage characteristics, current efficiency-luminance characteristics, and luminance-voltage characteristics. This is partly due to the fact that the layer containing the composite material of the present invention does not have a large absorption peak in the visible region. In addition, since the layer including the composite material of the present invention has high conductivity, it exhibits good current-voltage characteristics.

That is, it can be seen that by using the composite material of the present invention for a light-emitting element, a driving voltage for obtaining light emission with constant luminance can be reduced. Specifically, the voltage necessary for emitting light with a luminance of 1000 cd / m ² was 5.8 V in the element 17, and the current density at this time was 9.1 mA / cm ² . That is, it can be seen that low voltage driving and low current driving are possible by using the composite material of the present invention for a light emitting element.

  In addition, FIG. 90 shows power efficiency-luminance characteristics of the element 17 manufactured in this example. Higher power efficiency means lower power consumption, and FIG. 90 shows that the light-emitting element of the present invention exhibits good power efficiency.

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. 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. 4A and 4B illustrate a light-emitting device of the present invention. 4A and 4B illustrate a light-emitting device of the present invention. 6A and 6B illustrate an electric appliance using a light-emitting device of the present invention. 4A and 4B illustrate a light-emitting element of the present invention. 3 shows a ¹ H-NMR chart of [N-(9-phenyl-carbazol-3-yl) -N- phenylamino] -9-phenylcarbazole. 3 shows a ¹ H-NMR chart of [N-(9-phenyl-carbazol-3-yl) -N- phenylamino] -9-phenylcarbazole. The figure which shows the absorption spectrum of 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole. The figure which shows the emission spectrum of 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole. 3,6-bis shows a ¹ H-NMR chart of [N-(9-phenyl-carbazol-3-yl) -N- phenylamino] -9-phenylcarbazole. 3,6-bis shows a ¹ H-NMR chart of [N-(9-phenyl-carbazol-3-yl) -N- phenylamino] -9-phenylcarbazole. FIG. 6 shows an absorption spectrum of 3,6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole. FIG. 6 shows an emission spectrum of 3,6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole. The figure which shows the thermogravimetry result of 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole. The figure which shows the thermogravimetry result of 3,6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole. The figure which shows the CV characteristic of 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole. The figure which shows the CV characteristic of 3, 6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole. The figure which shows the measurement result which carried out the differential scanning calorimetric analysis of 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole. The figure which shows the measurement result which carried out the differential scanning calorimetric analysis of 3, 6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole. It shows a ¹ H-NMR chart of 3- (N- phenylamino) -9-phenyl carbazole. It shows a ¹ H-NMR chart of 3- (N- phenylamino) -9-phenyl carbazole. 3- [N- (1- naphthyl) amino] shows a ¹ H-NMR chart of 9-phenyl-carbazole. 3- [N- (1- naphthyl) amino] shows a ¹ H-NMR chart of 9-phenyl-carbazole. FIG. 3 shows a ¹ H-NMR chart of 3- [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole. FIG. 3 shows a ¹ H-NMR chart of 3- [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole. 4A and 4B illustrate a light-emitting element of the present invention. The figure which shows the absorption spectrum of the composite material of this invention. The figure which shows the absorption spectrum of the composite material of this invention. The figure which shows the transmittance | permeability of the composite material of this invention. FIG. 11 shows current-voltage characteristics of the light-emitting element manufactured in Example 7. FIG. 11 shows luminance-voltage characteristics of the light-emitting element manufactured in Example 7. FIG. 13 shows current efficiency-luminance characteristics of the light-emitting element manufactured in Example 7. FIG. 9 shows changes in normalized luminance time of light-emitting elements manufactured in Example 7. FIG. 11 shows voltage-time variations of the light-emitting element manufactured in Example 7. The figure which shows the thermogravimetry result of 3- [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole which is a carbazole derivative of the present invention. FIG. 9 shows an absorption spectrum of 3- [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole which is a carbazole derivative of the present invention. FIG. 9 shows an emission spectrum of 3- [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole which is a carbazole derivative of the present invention. FIG. 11 shows current-voltage characteristics of light-emitting elements manufactured in Example 9 and Example 10. FIG. 11 shows luminance-voltage characteristics of light-emitting elements manufactured in Example 9 and Example 10. FIG. 11 shows current efficiency-luminance characteristics of light-emitting elements manufactured in Example 9 and Example 10. FIG. 11 shows current-voltage characteristics of light-emitting elements manufactured in Example 11 and Example 12. FIG. 13 shows luminance-voltage characteristics of light-emitting elements manufactured in Example 11 and Example 12. FIG. 14 shows current efficiency-luminance characteristics of light-emitting elements manufactured in Example 11 and Example 12. The figure which shows the CV characteristic of 3- [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole which is a carbazole derivative of the present invention. The figure which shows the measurement result which carried out the differential scanning calorimetric analysis of 3- [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole which is the carbazole derivative of this invention. The perspective view of a vapor deposition apparatus. FIG. 25 shows current efficiency-luminance characteristics of the element manufactured in Example 14. FIG. 16 shows current-voltage characteristics of the element manufactured in Example 14. FIG. 16 shows luminance-voltage characteristics of the element manufactured in Example 14. The figure which shows the absorption spectrum of the composite material of this invention. The figure which shows the transmittance | permeability of the composite material of this invention. FIG. 18 shows current-voltage characteristics of an element manufactured in Example 17. FIG. 25 shows current-voltage characteristics of the element manufactured in Example 18. FIG. 25 shows current efficiency-luminance characteristics of the element manufactured in Example 18. FIG. 25 shows luminance-voltage characteristics of the element manufactured in Example 18. FIG. 25 shows current-voltage characteristics of the element manufactured in Example 19. FIG. 25 shows current efficiency-luminance characteristics of the element manufactured in Example 19. FIG. 25 shows luminance-voltage characteristics of the element manufactured in Example 19. FIG. 25 shows power efficiency-luminance characteristics of the element manufactured in Example 19. FIG. 25 shows changes in normalized luminance over time of the element manufactured in Example 19; FIG. 18 shows normalized luminance change with time of the element manufactured in Example 20; FIG. 16 shows power efficiency-luminance characteristics of the light-emitting element manufactured in Example 14. The figure which shows the ESR measurement result of the layer containing PCzPCA1 and molybdenum oxide. The figure which shows the ESR measurement result of PCzPCA1 single membrane. The figure which shows the ESR measurement result of a molybdenum oxide single film. The figure which shows the light absorbency per micrometer of the composite material of this invention. The figure which shows the light absorbency per micrometer of the composite material of this invention. 3 shows a ¹ H-NMR chart of the {N-[9-(4-biphenylyl) carbazol-3-yl] -N- phenylamino} -9- (4-biphenylyl) carbazole. The figure which shows the ¹³ C-NMR chart of 3- {N- [9- (4-biphenylyl) carbazol-3-yl] -N-phenylamino} -9- (4-biphenylyl) carbazole. The figure which shows the DSC chart of 3- {N- [9- (4-biphenylyl) carbazol-3-yl] -N-phenylamino} -9- (4-biphenylyl) carbazole. The figure which shows the absorption spectrum of the toluene solution of 3- {N- [9- (4-biphenylyl) carbazol-3-yl] -N-phenylamino} -9- (4-biphenylyl) carbazole which is the carbazole derivative of the present invention. . The figure which shows the emission spectrum of the toluene solution of 3- {N- [9- (4-biphenylyl) carbazol-3-yl] -N-phenylamino} -9- (4-biphenylyl) carbazole which is the carbazole derivative of the present invention. . FIG. 6 shows an absorption spectrum of a thin film of 3- {N- [9- (4-biphenylyl) carbazol-3-yl] -N-phenylamino} -9- (4-biphenylyl) carbazole which is a carbazole derivative of the present invention. The figure which shows the emission spectrum of the thin film of 3- {N- [9- (4-biphenylyl) carbazol-3-yl] -N-phenylamino} -9- (4-biphenylyl) carbazole which is a carbazole derivative of the present invention. It shows a ¹ H-NMR chart of 3,6-dibromo-9- (4-biphenylyl) carbazole. The figure which shows the ¹³ C-NMR chart of 3, 6- dibromo-9- (4-biphenylyl) carbazole. FIG. 6 shows a ¹ H-NMR chart of 3,6-bis [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9- (4-biphenylyl) carbazole. FIG. 9 shows a ¹³ C-NMR chart of 3,6-bis [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9- (4-biphenylyl) carbazole. The figure which shows the DSC chart of 3,6-bis [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9- (4-biphenylyl) carbazole. FIG. 6 shows an absorption spectrum of 3,6-bis [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9- (4-biphenylyl) carbazole. FIG. 9 shows an emission spectrum of 3,6-bis [N- (1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9- (4-biphenylyl) carbazole. FIG. 26 shows current-voltage characteristics of the element manufactured in Example 26. FIG. 26 shows current efficiency-luminance characteristics of the element manufactured in Example 26. FIG. 26 shows luminance-voltage characteristics of the element manufactured in Example 26. FIG. 26 shows power efficiency-luminance characteristics of the element manufactured in Example 26.

Explanation of symbols

101 substrate 102 first electrode 103 first layer 104 second layer 105 third layer 106 fourth layer 107 second electrode 200 substrate 201 first electrode 202 second electrode 211 first layer 212 2nd layer 213 3rd layer 214 4th layer 302 1st electrode 303 1st layer 304 2nd layer 305 3rd layer 306 4th layer 307 2nd electrode 400 substrate 401 1st Electrode 402 Second electrode 411 First layer 412 Second layer 413 Third layer 501 First electrode 502 Second electrode 511 First light emitting unit 512 Second light emitting unit 513 Charge generation layer 601 Source side Drive circuit 602 Pixel portion 603 Gate side drive 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
700 Deposition chamber 701 Substrate 702 Deposition mask 703a Deposition shield 703b Opening 704 Deposition source 705 Arrow 706 Arrow 707 Installation chamber 708 Deposition source 709 Deposition shield 710 Arrow 951 Substrate 952 Electrode 953 Insulating layer 954 Partition layer 955 Including luminescent material Layer 956 Electrode 1101 First electrode 1102 Second electrode 1111 First layer 1112 Second layer 1113 Third layer 1114 Fourth layer 9101 Housing 9102 Support base 9103 Display portion 9104 Speaker portion 9105 Video input terminal 9201 Main body 9202 Case 9203 Display unit 9204 Keyboard 9205 External connection port 9206 Pointing mouse 9301 Main body 9302 Display unit 9303 Arm unit 9401 Main body 9402 Display unit 9403 Display unit 9404 Audio input unit 9405 Audio output unit 9 406 Operation key 9407 External connection port 9408 Antenna 9501 Main body 9502 Display unit 9503 Case 9503 External connection port 9505 Remote control reception unit 9506 Image receiving unit 9507 Battery 9508 Audio input unit 9509 Operation key 9510 Eyepiece unit

Claims (8)

A composite material comprising a carbazole derivative represented by the general formula (1) and a transition metal oxide .

^{(Wherein, R 11} and ^{R 13} may be the same as or different from each other, an aryl group having a carbon number of 6-25, a heteroaryl group having 5 to 9 carbon atoms, an arylalkyl group, an acyl having 1 to 7 carbon atoms Ar ¹¹ represents any of a group, Ar ¹¹ represents an aryl group having 6 to 25 carbon atoms (excluding a perylenyl group) or a heteroaryl group having 5 to 9 carbon atoms, and R ¹² represents hydrogen or carbon number 1 -6 represents an alkyl group having 6 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and R ¹⁴ represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms.) A composite material comprising a carbazole derivative represented by the general formula (1) and a transition metal oxide .

(Wherein R ¹¹ and R ¹³ may be the same as or different from each other, hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 25 carbon atoms, a heteroaryl group having 5 to 9 carbon atoms, arylalkyl group, or an acyl group having 1 to 7 carbon atoms, ^{Ar 11} represents an aryl group having 6 to 25 carbon atoms, any of the heteroaryl group having 5 to 9 carbon ^{atoms, R 12} is, Represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms, and R ¹⁴ represents a substituent represented by the general formula (2), and is represented by the general formula (2). In the substituent, R ¹⁵ represents an aryl group having 6 to 25 carbon atoms or a heteroaryl group having 5 to 9 carbon atoms, Ar ¹² represents an aryl group having 6 to 25 carbon atoms, or a heteroaryl group having 5 to 9 carbon atoms. or an aryl ^{group, R 16} is hydrogen, Alkyl group of prime 1-6, and an aryl group having 6 to 12 carbon atoms.)
A composite material comprising a carbazole derivative represented by the general formula (7) and a transition metal oxide .

(In the formula, Ar ³¹ represents a phenyl group or a naphthyl group.) A composite material comprising a carbazole derivative represented by the general formula (8) and a transition metal oxide .

(In the formula, Ar ⁴¹ and Ar ⁴² may be the same or different and each represents a phenyl group or a naphthyl group.) In any one of Claims 1 thru | or 4 ,
The transition metal oxide is titanium oxide, vanadium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide. A composite material characterized by being one or more of the above. Having a layer containing a light-emitting substance between a pair of electrodes,
The light emitting element including the layer containing the composite material according to any one of claims 1 to 5 , wherein the layer containing the light emitting substance. A light emitting device comprising: the light emitting element according to claim 6; and a control unit that controls light emission of the light emitting element. Having a display,
The electric device comprising the light emitting element according to claim 6 and a control unit that controls light emission of the light emitting element.