Abstract: A light-emitting element having low driving voltage and high emission efficiency is provided. In the light-emitting element, a combination of a guest material and a host material forms an exciplex. The guest material is capable of converting triplet excitation energy into light emission. Light emission from the light-emitting layer includes light emission from the guest material and light emission from the exciplex. The percentage of the light emission from the exciplex to the light emission from the light-emitting layer is greater than 0 percent and less than or equal to 60 percent. The energy after subtracting the energy of light emission from the exciplex from the energy of light emission from the guest material is greater than 0 eV and less than or equal to 0.23 eV.

Abstract: A light-emitting element with high emission efficiency and high reliability is provided. The light-emitting element includes a light-emitting layer containing a first organic compound, a second organic compound, and a guest material. The first organic compound has a nitrogen-containing six-membered heteroaromatic skeleton. In the light-emitting layer, the weight ratio of an organic compound having a nitrogen-containing five-membered heterocyclic skeleton with an NH group, a secondary amine skeleton with an NH group, or a primary amine skeleton with an NH group to the first organic compound is less than or equal to 0.03, or alternatively, the weight ratio of the organic compound having a nitrogen-containing five-membered heterocyclic skeleton with an NH group, a secondary amine skeleton with an NH group, or a primary amine skeleton with an NH group to the second organic compound is less than or equal to 0.01.

Abstract: A light-emitting element having low driving voltage and high emission efficiency is provided. In the light-emitting element, a combination of a guest material and a host material forms an exciplex. The guest material is capable of converting triplet excitation energy into light emission. Light emission from the light-emitting layer includes light emission from the guest material and light emission from the exciplex. The percentage of the light emission from the exciplex to the light emission from the light-emitting layer is greater than 0 percent and less than or equal to 60 percent. The energy after subtracting the energy of light emission from the exciplex from the energy of light emission from the guest material is greater than 0 eV and less than or equal to 0.23 eV.

Abstract: A light-emitting element having low driving voltage and high emission efficiency is provided. In the light-emitting element, a combination of a guest material and a host material forms an exciplex. The guest material is capable of converting triplet excitation energy into light emission. Light emission from the light-emitting layer includes light emission from the guest material and light emission from the exciplex. The percentage of the light emission from the exciplex to the light emission from the light-emitting layer is greater than 0 percent and less than or equal to 60 percent. The energy after subtracting the energy of light emission from the exciplex from the energy of light emission from the guest material is greater than 0 eV and less than or equal to 0.23 eV.

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 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: 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: Providing a light-emitting element emitting light in a broad emission spectrum. A combination of a first organic compound and a second organic compound forms an exciplex. The first organic compound has a function of converting triplet-excitation energy into light emission. The lowest triplet excitation level of the second organic compound is higher than or equal to the lowest triplet excitation level of the first organic compound, and the lowest triplet excitation level of the first organic compound is higher than or equal to the lowest triplet excitation level of the exciplex. Light emission from a light-emitting layer includes light emission from the first organic compound and light emission from the 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: Providing a light-emitting element emitting light in a broad emission spectrum. A combination of a first organic compound and a second organic compound forms an exciplex. The first organic compound has a function of converting triplet-excitation energy into light emission. The lowest triplet excitation level of the second organic compound is higher than or equal to the lowest triplet excitation level of the first organic compound, and the lowest triplet excitation level of the first organic compound is higher than or equal to the lowest triplet excitation level of the exciplex. Light emission from a light-emitting layer includes light emission from the first organic compound and light emission from the exciplex.

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: 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 light-emitting element having low driving voltage and high emission efficiency is provided. In the light-emitting element, a combination of a guest material and a host material forms an exciplex. The guest material is capable of converting triplet excitation energy into light emission. Light emission from the light-emitting layer includes light emission from the guest material and light emission from the exciplex. The percentage of the light emission from the exciplex to the light emission from the light-emitting layer is greater than 0 percent and less than or equal to 60 percent. The energy after subtracting the energy of light emission from the exciplex from the energy of light emission from the guest material is greater than 0 eV and less than or equal to 0.23 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: Providing a light-emitting element emitting light in a broad emission spectrum. A combination of a first organic compound and a second organic compound forms an exciplex. The first organic compound has a function of converting triplet-excitation energy into light emission. The lowest triplet excitation level of the second organic compound is higher than or equal to the lowest triplet excitation level of the first organic compound, and the lowest triplet excitation level of the first organic compound is higher than or equal to the lowest triplet excitation level of the exciplex. Light emission from a light-emitting layer includes light emission from the first organic compound and light emission from the exciplex.

Abstract: A novel organometallic complex is provided. An organometallic complex emitting green to blue phosphorescence is provided. An organometallic complex having a deep LUMO level and emitting green to blue phosphorescence is provided. A light-emitting element with high emission efficiency is provided. A light-emitting element emitting green to blue phosphorescence and having low drive voltage is provided. A light-emitting device with low power consumption is provided. The organometallic complex includes iridium and a ligand having a triazole skeleton. The triazole skeleton has a group including a pyridine ring or a group including a pyrimidine ring and an aryl group. One of nitrogen atoms included in the triazole skeleton is coordinated to the iridium. The aryl group is bonded to the iridium at the ortho position of the aryl group.

Abstract: A light-emitting element with high emission efficiency and high reliability is provided. The light-emitting element includes a light-emitting layer containing a first organic compound, a second organic compound, and a guest material. The first organic compound has a nitrogen-containing six-membered heteroaromatic skeleton. In the light-emitting layer, the weight ratio of an organic compound having a nitrogen-containing five-membered heterocyclic skeleton with an NH group, a secondary amine skeleton with an NH group, or a primary amine skeleton with an NH group to the first organic compound is less than or equal to 0.03, or alternatively, the weight ratio of the organic compound having a nitrogen-containing five-membered heterocyclic skeleton with an NH group, a secondary amine skeleton with an NH group, or a primary amine skeleton with an NH group to the second organic compound is less than or equal to 0.01.

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.