Abstract: A light-emitting element having a long lifetime is provided. A light-emitting element exhibiting high emission efficiency in a high luminance region is provided. A light-emitting element includes a light-emitting layer between a pair of electrodes. The light-emitting layer contains a first organic compound, a second organic compound, and a phosphorescent compound. The first organic compound is represented by a general formula (G0). The molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000. The second organic compound is a compound having an electron-transport property. In the general formula (G0), Ar1 and Ar2 each independently represent a fluorenyl group, a spirofluorenyl group, or a biphenyl group, and Ar3 represents a substituent including a carbazole skeleton.

Abstract: A novel heterocyclic compound is provided. In particular, a novel heterocyclic compound which can improve the element characteristics of the light-emitting element is provided. The heterocyclic compound is represented by a general formula (G1) DBqAr1nAr2-A??(G1) in which a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group and a substituted or unsubstituted benzobisbenzofuranyl group are bonded to each other via a substituted or unsubstituted arylene group. In the general formula (G1), DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group, Ar1 represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, n represents 0 or 1, Ar2 represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and A represents a substituted or unsubstituted benzobisbenzofuranyl group. When the arylene group represented by Ar1 and Ar2 has substituents, the substituents may be bonded to each other to form a ring.

Abstract: To provide a light-emitting element with an improved reliability, a light-emitting element with a high current efficiency (or a high quantum efficiency), and a novel dibenzo[f,h]quinoxaline derivative that is favorably used in a light-emitting element which is one embodiment of the present invention. A light-emitting element includes an EL layer between an anode and a cathode. The EL layer includes a light-emitting layer; the light-emitting layer contains a first organic compound having an electron-transport property and a hole-transport property, a second organic compound having a hole-transport property, and a light-emitting substance; the combination of the first organic compound and the second organic compound forms an exciplex; the HOMO level of the first organic compound is lower than the HOMO level of the second organic compound; and a difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is less than or equal to 0.4 eV.

Abstract: A novel organic compound that can be used as a carrier-transport material, a host material, or a light-emitting material in a light-emitting element is provided. Specifically, an organic compound that can give a light-emitting element having favorable characteristics even when the organic compound is used in a light-emitting element emitting phosphorescence is provided. The organic compound has a bipyridine skeleton formed by two pyridine skeletons to each of which a dibenzothiophenyl group or a dibenzofuranyl group is bonded via an arylene group.

Abstract: A novel organic compound that can be used as a carrier-transport material, a host material, or a light-emitting material in a light-emitting element is provided. Specifically, an organic compound that can give a light-emitting element having favorable characteristics even when the organic compound is used in a light-emitting element emitting phosphorescence is provided. The organic compound has a bipyridine skeleton formed by two pyridine skeletons to each of which a dibenzothiophenyl group or a dibenzofuranyl group is bonded via an arylene group.

Abstract: A novel heterocyclic compound is provided. In particular, a novel heterocyclic compound which can improve the element characteristics of a light-emitting element is provided. A novel light-emitting element with high emission efficiency and high heat resistance is provided. A heterocyclic compound represented by General Formula (G1). A represents any of a dibenzothiophenyl group, a dibenzofuranyl group, and a carbazolyl group. DBq represents a dibenzo[f,h]quinoxalinyl group. In addition, n is 0 or 1. Each of Ar1 to Ar4 independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. In Ar1 to Ar4, the adjacent arylene groups may be bonded to each other to form a ring. When the adjacent arylene groups in Ar1 to Ar4 form a fluorene skeleton, the fluorene skeleton may have a substituent.

Abstract: Provided is a novel light-emitting element, a light-emitting element with a long lifetime, or a light-emitting element with high luminous efficiency. The light-emitting element includes an anode, a cathode, a light-emitting layer, and a hole-injection layer. The light-emitting layer and the hole-injection layer are between the anode and the cathode. The hole-injection layer is closer to the anode than the light-emitting layer is. The light-emitting layer contains a light-emitting substance. The hole-injection layer contains a first substance which is an organic compound having a hole-transport property and a second substance which is a substance having an electron acceptor property with respect to the first substance. The light-emitting substance is a quantum dot.

Abstract: Provided is a light-emitting element including a first organic compound, a second organic compound, and a guest material. The LUMO level of the first organic compound is lower than that of the second organic compound. The HOMO level of the first organic compound is lower than that of the second organic compound. The LUMO level of the guest material is higher than that of the first organic compound. The HOMO level of the guest material is higher than that of the second organic compound. An energy difference between the LUMO level and the HOMO level of the guest material is larger than an energy difference between the LUMO level of the first organic compound and the HOMO level of the second organic compound. The guest material can convert triplet excitation energy into light emission. The combination of first organic compound and the second organic compound can form an exciplex.

Abstract: A novel heterocyclic compound is provided. In particular, a novel heterocyclic compound which can improve the element characteristics of the light-emitting element is provided. The heterocyclic compound is represented by a general formula (G1) DBq-(Ar1)-n-Ar2-A ??(G1) in which a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group and a substituted or unsubstituted benzobisbenzofuranyl group are bonded to each other via a substituted or unsubstituted arylene group. In the general formula (G1), DBq represents a substituted or unsubstituted dibenzo [f,h] quinoxalinyl group, Ar1 represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, n represents 0 or 1, Ar2 represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, and A represents a substituted or unsubstituted benzobisbenzofuranyl group. When the arylene group represented by Ar1 and Ar2 has substituents, the substituents may be bonded to each other to form a ring.

Abstract: A novel organic compound having a high hole-transport property is provided. A long-lifetime light-emitting element is provided. An organic compound represented by General Formula (G0) is provided. In General Formula (G0), Ar1 represents a substituted or unsubstituted naphthyl group, Ar2 represents a substituted or unsubstituted carbazolyl group, Ar3 represents a substituted or unsubstituted fluorenyl group or a substituted or unsubstituted spirofluorenyl group, and ?1 and ?2 each independently represent a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenyldiyl group.

Abstract: A light-emitting element having a long lifetime is provided. A light-emitting element exhibiting high emission efficiency in a high luminance region is provided. A light-emitting element includes a light-emitting layer between a pair of electrodes. The light-emitting layer contains a first organic compound, a second organic compound, and a phosphorescent compound. The first organic compound is represented by a general formula (G0). The molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000. The second organic compound is a compound having an electron-transport property. In the general formula (G0), Ar1 and Ar2 each independently represent a fluorenyl group, a spirofluorenyl group, or a biphenyl group, and Ar3 represents a substituent including a carbazole skeleton.

Abstract: A novel phosphorescent organometallic iridium complex is provided in which a coordination position of a ligand with respect to a metal can be controlled in synthesis. A novel phosphorescent organometallic iridium complex is provided which can keep high quantum efficiency and can emit phosphorescence in the blue to green wavelength region. A phosphorescent organometallic iridium complex which includes a structure represented by General Formula (G1) and whose ligand is a 4H-1,2,4-triazole compound which has an unsubstituted phenyl group at the 3-position, a substituted or unsubstituted phenyl group at the 4-position, and a phenyl group at the 5-position. In the phenyl group at the 5-position, an alkyl group is bonded to at least one of the ortho-positions, and the other of the ortho-positions, the meta-positions, and the para-position are substituted or unsubstituted.

Abstract: An organometallic complex that has high emission efficiency and high heat resistance and emits blue light is provided as a novel substance. In a light-emitting element including a light-emitting layer between a pair of electrodes, the light-emitting layer includes an organometallic complex, and the organometallic complex includes a central metal and two types of ligands coordinated to the central metal. One of the two types of ligands includes a triazole skeleton including nitrogen bonded to the central metal, and the other includes a nitrogen-containing five-membered heterocyclic skeleton including carbene carbon bonded to the central metal and nitrogen bonded to carbene carbon.

Abstract: A novel organic compound having a high hole-transport property is provided. A long-lifetime light-emitting element is provided. An organic compound represented by General Formula (G0) is provided. In General Formula (G0), Ar1 represents a substituted or unsubstituted naphthyl group, Ar2 represents a substituted or unsubstituted carbazolyl group, Ar3 represents a substituted or unsubstituted fluorenyl group or a substituted or unsubstituted spirofluorenyl group, and ?1 and ?2 each independently represent a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenyldiyl group.

Abstract: A light-emitting element having a long lifetime is provided. A light-emitting element exhibiting high emission efficiency in a high luminance region is provided. A light-emitting element includes a light-emitting layer between a pair of electrodes. The light-emitting layer contains a first organic compound, a second organic compound, and a phosphorescent compound. The first organic compound is represented by a general formula (G0). The molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000. The second organic compound is a compound having an electron-transport property. In the general formula (G0), Ar1 and Ar2 each independently represent a fluorenyl group, a spirofluorenyl group, or a biphenyl group, and Ar3 represents a substituent including a carbazole skeleton.

Abstract: The organic compound represented by Formula G1 below has a structure in which the 2-position of a dibenzoquinazoline ring is directly, or via one or more arylene groups, bonded to a skeleton with a hole-transport property. In the formula, n represents any of 0 to 3, m represents 1 or 2, A represents a single bond, or a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, B represents a ring having a substituted or unsubstituted dibenzofuran skeleton, a substituted or unsubstituted dibenzothiophene skeleton, or a substituted or unsubstituted carbazole skeleton, and each of R1 to R14 independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

Abstract: A novel phosphorescent organometallic iridium complex is provided in which a coordination position of a ligand with respect to a metal can be controlled in synthesis. A novel phosphorescent organometallic iridium complex is provided which can keep high quantum efficiency and can emit phosphorescence in the blue to green wavelength region. A phosphorescent organometallic iridium complex which includes a structure represented by General Formula (G1) and whose ligand is a 4H-1,2,4-triazole compound which has an unsubstituted phenyl group at the 3-position, a substituted or unsubstituted phenyl group at the 4-position, and a phenyl group at the 5-position. In the phenyl group at the 5-position, an alkyl group is bonded to at least one of the ortho-positions, and the other of the ortho-positions, the meta-positions, and the para-position are substituted or unsubstituted.

Abstract: An organic compound represented by a general formula (G1). In the general formula (G1), Het represents a substituted or unsubstituted ?-electron deficient divalent heteroaromatic group having 4 to 36 carbon atoms, Ar1 and Ar2 each independently represent a substituted or unsubstituted arylene group having 6 to 25 carbon atoms, in and n each independently represent a natural number greater than or equal to 1 and less than or equal to 5, and A1 and A2 each independently represent any of a substituted or unsubstituted benzothienocarbazolyl group, a substituted or unsubstituted benzofurocarbazolyl group, and a substituted or unsubstituted indenocarbazolyl group.

Abstract: An object is to provide a novel organometallic complex. Another object is to provide an organometallic complex exhibiting green to blue phosphorescence. Another object is to provide an organometallic complex having deep HOMO and exhibiting green to blue phosphorescence. Another object is to provide a light-emitting element with high emission efficiency. Another object is to provide a light-emitting element exhibiting green to blue phosphorescence and having low drive voltage. To provide an organometallic complex which includes a 1,2,4-triazole skeleton and in which an N-carbazolyl group is bonded to the 3-position of the 1,2,4-triazole skeleton via a phenylene group, a phenyl group is bonded to the 4-position of the 1,2,4-triazole skeleton, the 2-position of the 1,2,4-triazole skeleton coordinates to iridium, and the phenylene group is bonded to the iridium. To provide a light-emitting element including the organometallic complex as an emission center.

Abstract: To provide a light-emitting element with an improved reliability, a light-emitting element with a high current efficiency (or a high quantum efficiency), and a novel dibenzo[f,h]quinoxaline derivative that is favorably used in a light-emitting element which is one embodiment of the present invention. A light-emitting element includes an EL layer between an anode and a cathode. The EL layer includes a light-emitting layer; the light-emitting layer contains a first organic compound having an electron-transport property and a hole-transport property, a second organic compound having a hole-transport property, and a light-emitting substance; the combination of the first organic compound and the second organic compound forms an exciplex; the HOMO level of the first organic compound is lower than the HOMO level of the second organic compound; and a difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is less than or equal to 0.4 eV.