Abstract: A composite material which includes an organic compound and an inorganic compound and has a high carrier-transport property is provided. A composite material having a good property of carrier injection into an organic compound is provided. A composite material in which light absorption due to charge-transfer interaction is unlikely to occur is provided. A composite material having a high visible-light-transmitting property is provided. A composite material including a hydrocarbon compound and an inorganic compound exhibiting an electron-accepting property with respect to the hydrocarbon compound is provided. The hydrocarbon compound has a substituent bonded to a naphthalene skeleton, a phenanthrene skeleton, or a triphenylene skeleton and has a molecular weight of 350 to 2000, and the substituent has one or more rings selected from a benzene ring, a naphthalene ring, a phenanthrene ring, and a triphenylene ring.

Abstract: An object is to provide a light-emitting element with high emission efficiency which includes a novel carbazole derivative that has a wide energy gap and can be used for a transport layer or a host material in a light-emitting element. A carbazole derivative in which the 4-position of dibenzothiophene or dibenzofuran is bonded to the 2- or 3-position of carbazole has been able to be provided by use of the carbazole derivative. Further, a light-emitting element having high emission efficiency has been able to be provided by use of the carbazole derivative.

Abstract: An object is to provide a light-emitting element with high emission efficiency which includes a novel carbazole derivative that has a wide energy gap and can be used for a transport layer or a host material in a light-emitting element. A carbazole derivative in which the 4-position of dibenzothiophene or dibenzofuran is bonded to the 2- or 3-position of carbazole has been able to be provided by use of the carbazole derivative. Further, a light-emitting element having high emission efficiency has been able to be provided by use of the carbazole derivative.

Abstract: A novel substance with which an increase in life and emission efficiency of a light-emitting element can be achieved is provided. A carbazole compound having a structure represented by General Formula (G1) is provided. Note that a substituent which makes the HOMO level and the LUMO level of a compound in which a bond of the substituent is substituted with hydrogen deep and shallow, respectively is used as each of substituents in General Formula (G1) (R1, R2, Ar3, and ?3). Further, a substituent which makes the band gap (Bg) and the T1 level of a compound in which a bond of the substituent is substituted with hydrogen wide and high is used as each of the substituents in General Formula (G1) (R1, R2, Ar3, and ?3).

Abstract: A novel substance with which an increase in life and emission efficiency of a light-emitting element can be achieved is provided. A carbazole compound having a structure represented by General Formula (G1) is provided. Note that a substituent which makes the HOMO level and the LUMO level of a compound in which a bond of the substituent is substituted with hydrogen deep and shallow, respectively is used as each of substituents in General Formula (G1) (R1, R2, Ar3, and ?3). Further, a substituent which makes the band gap (Bg) and the T1 level of a compound in which a bond of the substituent is substituted with hydrogen wide and high is used as each of the substituents in General Formula (G1) (R1, R2, Ar3, and ?3).

Abstract: A composite material including an organic compound and an inorganic compound and having a high carrier-transport property is provided. A composite material having a high carrier-injection property to an organic compound is provided. A composite material in which light absorption due to charge transfer interaction is unlikely to occur is provided. A light-emitting element having high emission efficiency is provided by including the composite material. A light-emitting element having a low drive voltage is provided. A light-emitting element having a long lifetime is provided. A composite material including a heterocyclic compound having a dibenzothiophene skeleton or a dibenzofuran skeleton and an inorganic compound exhibiting an electron-accepting property with respect to the heterocyclic compound is provided.

Abstract: A substance having a hole-transport property and a wide band gap is provided. A fluorene compound represented by a general formula (G1) is provided. In the general formula (G1), ?1 and ?2 separately represent a substituted or unsubstituted arylene group having 6 to 13 carbon atoms; Ar1 represents a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, a substituted or unsubstituted 4-dibenzothiophenyl group, or a substituted or unsubstituted 4-dibenzofuranyl group; n and k separately represent 0 or 1; Q1 represents sulfur or oxygen; and R1 to R15 separately represent hydrogen, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 14 carbon atoms.

Abstract: A composite material including an organic compound and an inorganic compound and having a high carrier-transport property is provided. A composite material having a high carrier-injection property to an organic compound is provided. A composite material in which light absorption due to charge transfer interaction is unlikely to occur is provided. A light-emitting element having high emission efficiency is provided by including the composite material. A light-emitting element having a low drive voltage is provided. A light-emitting element having a long lifetime is provided. A composite material including a heterocyclic compound having a dibenzothiophene skeleton or a dibenzofuran skeleton and an inorganic compound exhibiting an electron-accepting property with respect to the heterocyclic compound is provided.

Abstract: A composite material which includes an organic compound and an inorganic compound and has a high carrier-transport property is provided. A composite material having a good property of carrier injection into an organic compound is provided. A composite material in which light absorption due to charge-transfer interaction is unlikely to occur is provided. A composite material having a high visible-light-transmitting property is provided. A composite material including a hydrocarbon compound and an inorganic compound exhibiting an electron-accepting property with respect to the hydrocarbon compound is provided. The hydrocarbon compound has a substituent bonded to a naphthalene skeleton, a phenanthrene skeleton, or a triphenylene skeleton and has a molecular weight of 350 to 2000, and the substituent has one or more rings selected from a benzene ring, a naphthalene ring, a phenanthrene ring, and a triphenylene ring.

Abstract: An object is to provide a light-emitting element capable of emitting light with a high luminance even at a low voltage, and having a long lifetime. The light-emitting element includes n EL layers between an anode and a cathode (n is a natural number of two or more), and also includes, between m-th EL layer from the anode and (m+1)-th EL layer (m is a natural number, 1?m?n?1), a first layer including a first donor material in contact with the m-th EL layer, a second layer including an electron-transport material and a second donor material in contact with the first layer, and a third layer including a hole-transport material and an acceptor material in contact with the second layer and the (m+1)-th EL layer.

Abstract: A substance having a hole-transport property and a wide band gap is provided. A heterocyclic compound represented by a general formula (G1) is provided. In the formula, ?1 and ?2 separately represent a substituted or unsubstituted arylene group having 6 to 13 carbon atoms; n and k separately represent 0 or 1; Q1 and Q2 separately represent sulfur or oxygen; and R1 to R22 separately represent hydrogen, an alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 14 carbon atoms.

Abstract: A composite material which includes an organic compound and an inorganic compound and has a high carrier-transport property is provided. A composite material having a good property of carrier injection into an organic compound is provided. A composite material in which light absorption due to charge-transfer interaction is unlikely to occur is provided. A composite material having a high visible-light-transmitting property is provided. A composite material including a hydrocarbon compound and an inorganic compound exhibiting an electron-accepting property with respect to the hydrocarbon compound is provided. The hydrocarbon compound has a substituent bonded to a naphthalene skeleton, a phenanthrene skeleton, or a triphenylene skeleton and has a molecular weight of 350 to 2000, and the substituent has one or more rings selected from a benzene ring, a naphthalene ring, a phenanthrene ring, and a triphenylene ring.

Abstract: An object is to provide a light-emitting element capable of emitting light with a high luminance even at a low voltage, and having a long lifetime. The light-emitting element includes n EL layers between an anode and a cathode (n is a natural number of two or more), and also includes, between m-th EL layer from the anode and (m+1)-th EL layer (m is a natural number, 1?m?n?1), a first layer including a first donor material in contact with the m-th EL layer, a second layer including an electron-transport material and a second donor material in contact with the first layer, and a third layer including a hole-transport material and an acceptor material in contact with the second layer and the (m+1)-th EL layer.

Abstract: Provided is a novel substance that can emit phosphorescence. Alternatively, provided is a novel substance with high emission efficiency. An organometallic complex in which a 4-arylpyrimidine derivative is a ligand and iridium is a central metal is provided. Specifically, an organometallic complex having a structure represented by a general formula (G1) is provided. In the general formula (G1), R1 represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, R2 represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and a substituted or unsubstituted phenyl group, R3 represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and Ar1 represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms.

Abstract: A light-emitting element that emits light with high luminance and can be driven at low voltage. The light-emitting element includes n (n is a natural number greater than or equal to 2) EL layers between an anode and a cathode, and includes a first layer, a second layer, and a third layer between an m-th (m is a natural number, 1?m?n?1) EL layer from the anode and an (m+1)th EL layer. The first layer functions as a charge-generation region, has hole-transport properties, and contains an acceptor substance. The third layer has electron-transport properties and contains an alkali metal or the like. The second layer is formed of a phthalocyanine-based material and is provided between the first layer and the third layer, whereby an injection barrier at the time of injecting electrons generated in the first layer into the m-th EL layer through the third layer can be lowered.

Abstract: Disclosed is a phosphorescent organometallic complex having: a 6-membered aromatic heterocycle having a nitrogen atom; iridium or platinum to which the nitrogen atom coordinates; and an aryl group which is bonded to an ?-carbon of the nitrogen atom and is ortho-metalated with the iridium or platinum, where at least one of the aromatic heterocycle and the aryl group has an alicyclic hydrocarbon having an intramolecular carbon-carbon bridged bond as a substituent. The ability of the bulky structure of the alicyclic hydrocarbon to inhibit aggregation of the organometallic complex, concerted with the strong electron-donating property of the alicyclic hydrocarbon to the aromatic heterocycle or the aryl group, contributes to the increase in absorption coefficient and phosphorescent efficiency of the organometallic complex. The improved absorption coefficient and the phosphorescent efficiency allow the formation of a light-emitting element with excellent external quantum efficiency over 25%.

Abstract: A light-emitting element is provided, in which n (n is a natural number of two or more) EL layers are provided between an anode and a cathode. Between the m-th (m is a natural number, 1?m?n?1) EL layer and the (m+1)-th EL layer, a first layer containing any of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth metal compound, and a rare earth metal compound, a second layer containing a substance having high electron-transport properties in contact with the first layer, and a charge-generation layer containing a substance having high hole-transport properties and an acceptor substance in contact with the second layer are provided in this order over the anode. The charge-generation layer does not have a peak of an absorption spectrum in a visible light region.

Abstract: Provided is a novel substance that can emit phosphorescence. Alternatively, provided is a novel substance with high emission efficiency. An organometallic complex in which a 4-arylpyrimidine derivative is a ligand and iridium is a central metal is provided. Specifically, an organometallic complex having a structure represented by a general formula (G1) is provided. In the general formula (G1), R1 represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, R2 represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and a substituted or unsubstituted phenyl group, R3 represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and Ar1 represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms.

Abstract: An object is to provide a light-emitting element with high emission efficiency which includes a novel carbazole derivative that has a wide energy gap and can be used for a transport layer or a host material in a light-emitting element. A carbazole derivative in which the 4-position of dibenzothiophene or dibenzofuran is bonded to the 2- or 3-position of carbazole has been able to be provided by use of the carbazole derivative. Further, a light-emitting element having high emission efficiency has been able to be provided by use of the carbazole derivative.

Abstract: To provide a novel carbazole compound that has an excellent carrier-transport property and can be used for a transport layer or as a host material in a light-emitting element. Further, to provide an organic semiconductor material and a material for a light-emitting element using the carbazole compound. A carbazole compound in which the 4-position of a dibenzothiophene skeleton or a dibenzofuran skeleton is substituted with the 2- or 3-position of a carbazole skeleton directly or via an arylene group can be synthesized. The carbazole compound is found to have a suitable carrier-transport property, a good film quality, and be used suitably as a material of a light-emitting element and an organic semicondcutor material. Note that nitrogen of the carbazole skeleton is substituted with any of a phenyl group, a biphenyl group, and a naphthyl group.