Synthesis and Characteristics of Hole-transporting Materials Based on Biphenyl Diamine Derivatives with Carbazole Groups

摘要

Two hole-transporting materials containing carbazole moieties with TPD- and NPB-like structures, 4,4′-bis [N-(4-carbazolylphenyl)-N-phenylamino] biphenyl (CPB) and 4,4′-bis [N-(4-carbazolylphenyl) -N-(1-naphthyl) amino] biphenyl (CNB), were synthesized via a modified Ullmann reaction. The resulting compounds were thermally stable with high glass transition temperatures ranging from 145 to 147℃ and possessed a good electrochemical reversibility and hole-transporting properties. Typical double-layer device evaluation with the structure ITO/CPB(40 nm)/Alq_3(60 nm)/LiF/Al demonstrated that they were promising hole-transporting materials with a current efficiency of 5.25 cd/A and a power efficiency of 2.00 lm/W.