A light-emitting element is disclosed where a host material and a hole-transport material each consist of a carbazole skeleton and another skeleton other than the carbazole skeleton. Both the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the hole-transport material are distributed over the carbazole skeleton, while the HOMO of the host material is distributed over the carbazole skeleton and the LUMO thereof is distributed over the skeleton other than the carbazole skeleton. This combination of the hole-transport material and the host material allows the fabrication of a light-emitting element with high emission efficiency and low driving voltage.
Provided is a bipolar substance having high excitation energy, in particular, high triplet-excitation energy. An oxadiazole derivative represented by General Formula (G1) below is provided
In the formula, Ar represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms in a ring. R
1
represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms in a ring. R
2
represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms in a ring.