Abstract: A novel light-emitting material is provided. A novel orgnometallic complex is provided. An orgnometallic complex having a high carrier-transport property is provided. An orgnometallic complex having a deep HOMO level and/or a deep LUMO level is provided. An orgnometallic complex having a high charge-injection property is provided. Another object is to provide an organometallic complex that can exhibit yellow to blue phosphorescence. An organometallic complex that has a high carrier-transport property and exhibits green to blue phosphorescence is provided. An organometallic complex including a ligand having a structure of 5-(2-pyridinyl)-5H-benzimidazo[1,2-a]benzimidazole and a light-emitting material including the organometallic complex are provided.

Abstract: To provide a light-emitting element with high emission efficiency and low driving voltage. The light-emitting element includes a guest material and a host material. A HOMO level of the guest material is higher than a HOMO level of the host material. An energy difference between the LUMO level and a HOMO level of the guest material is larger than an energy difference between the LUMO level and a HOMO level of the host material. The guest material has a function of converting triplet excitation energy into light emission. An energy difference between the LUMO level of the host material and the HOMO level of the guest material is larger than or equal to energy of light emission of the guest material.

Abstract: To provide a light-emitting element with high emission efficiency and low driving voltage. The light-emitting element includes a guest material and a host material. A LUMO level of the guest material is lower than a LUMO level of the host material. An energy difference between the LUMO level and a HOMO level of the guest material is larger than an energy difference between the LUMO level and a HOMO level of the host material. The guest material has a function of converting triplet excitation energy into light emission. An energy difference between the LUMO level of the guest material and the HOMO level of the host material is larger than or equal to energy of light emission of the guest material.

Abstract: Provided is a novel compound or a light-emitting element with high emission efficiency. The provided novel compound includes a bicarbazole skeleton and a benzofuropyrimidine skeleton or a benzothienopyrimidine skeleton. The provided light-emitting element includes the compound.

Abstract: To provide a light-emitting element with high emission efficiency and low driving voltage. The light-emitting element includes a guest material and a host material. A LUMO level of the host material is higher than a LUMO level of the host material, and a HOMO level of the guest material is lower than a HOMO level of the host material. The guest material has a function of converting triplet excitation energy into light emission. The difference between a singlet excitation energy level and a triplet excitation energy level of the host material is greater than 0 eV and less than or equal to 0.2 eV. The energy difference between the LUMO level and the HOMO level of the host material is larger than or equal to light emission energy of the guest material.

Abstract: A light-emitting element with high emission efficiency. The light-emitting element includes a first organic compound, a second organic compound, and a guest material. The LUMO level of the first organic compound is lower than the LUMO level of the second organic compound. The HOMO level of the first organic compound is lower than the HOMO level of the second organic compound. The HOMO level of the guest material is higher than the HOMO level of the second organic compound. The energy difference between the LUMO level of the guest material and the HOMO level of the guest material is larger than the energy difference between the LUMO level of the first organic compound and the HOMO level of the second organic compound. The guest material has a function of converting triplet excitation energy into light emission. The first organic compound and the second organic compound form an exciplex.

Abstract: Provided is a light-emitting element with high emission efficiency. The light-emitting element includes 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, and the HOMO level of the first organic compound is lower than that of the second organic compound. The LUMO level of a guest material is higher than that of the first organic compound, and the HOMO level of the guest material is lower than that of the second organic compound. The guest material has a function of converting triplet excitation energy into light emission. The first organic compound and the second organic compound form an exciplex.

Abstract: Provided is a novel substance that can be used in an element capable of emitting phosphorescence, a novel substance that contributes to high emission efficiency, or a novel substance that contributes to light emission with high color purity. A light-emitting element includes a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a substance including a carbazole skeleton. The substance is bonded to a substituted or unsubstituted first arylene group through a nitrogen atom included in the carbazole skeleton. The first arylene group is bonded to a substituted or unsubstituted benzofuropyridyl group or a substituted or unsubstituted benzothienopyridyl group. The first arylene group includes 1 to 5 substituted or unsubstituted second arylene groups which are bonded to one another. The EL layer may further include a layer including an emission center substance, specifically an iridium compound.

Abstract: A novel heterocyclic compound is provided. A highly efficient and reliable light-emitting element is provided. The heterocyclic compound is represented by a general formula (G1). In the general formula (G1), any one, two, or three of Y1 to Y4 in a ring A represent N atoms, and the rest of Y1 to Y4 represents CH. In the case where any two or three of the Y1 to Y4 are N atoms, the N atoms are not next to each other. Further, Ar1 represents a substituted or unsubstituted biphenyldiyl group, Ar2 represents a substituted or unsubstituted biphenyldiyl group, Cz1 represents a substituted or unsubstituted heterocyclic group including a carbazole skeleton, Cz2 represents a substituted or unsubstituted heterocyclic group including a carbazole skeleton, the carbazole skeleton included in the Cz1 is directly bonded to the Ar1, and the carbazole skeleton included in the Cz2 is directly bonded to the Ar2.

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: 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.