Structure and electronic properties of triphenylamine-substituted indolo[3,2-b]carbazole derivatives as hole-transporting materials for organic light-emitting diodes

Two triphenylamine-substituted indolo[3,2-b]carbazole compounds have been designed and synthesized as hole-transporting materials. The theoretical and experimental studies show that the difference of the substituted-positions has great effects on the optical and electrochemical properties. EL results indicate the indolo[3,2-b]carbazole compound with 6,12-disubstituted by triphenylamine possessing better hole-transporting performance than the 2,8-disubstituted one.