| 摘要 |
PROBLEM TO BE SOLVED: To provide an organic EL element improved in an emission lifetime.SOLUTION: There is provided a carbazole derivative represented by the general formula (1). In the general formula (1), substitution positions of dibenzoheterole rings of two carbazole rings are different from each other, X is O, S, SiRR, or GeRR, R-Ris an arbitrary substituent group, and a and b are integers of 0-3 independently each other. |
