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) (R
1
, R
2
, Ar
3
, and α
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) (R
1
, R
2
, Ar
3
, and α
3
).
提供一种新型物质,可以实现发光元件寿命和发射效率的提高。提供一种具有通用式(G1)表示的结构的
咔唑化合物。请注意,在通用式(G1)中,使取代基的HO
MO能级和LU
MO能级分别变深和变浅的取代基被用作每个取代基(R1、R2、Ar3和α3)。此外,在通用式(G1)中,使取代基的带隙(Bg)和T1能级分别变宽和变高的取代基被用作每个取代基(R1、R2、Ar3和α3)。