Synthesis and Hole-Transporting Properties of Phenyl-Carbazyl Derivatives

Abstract

We synthesized new hole-transporting material, 9,9′-diphenyl-9H,9′H-3,3′-bicarbazole(P-Cvz-2), 9,9′-diphenyl-6-(9-phenyl-9H-carbazol-3-yl)-9H,9′H-3,3′-bicarbazole(P-Cvz-3), 6-(9,9′-diphenyl-9H,9′H-3,3′-bicarbazol-6-yl)-9,9′-diphenyl-9H,9′H-3,3′-bicarbazole(P-Cvz-4A) and 9-phenyl-6-(9-phenyl-9H-3,9′-bicarbazol-6-yl)-9H-3,9′-bicarbazole(P-Cvz-4B). EL luminance efficiencies of P-Cvz-2, P-Cvz-3, P-Cvz-4A and P-Cvz-4B devices were found to be 5.24, 5.64, 4.86 and 4.94 cd/A at 50 mA/cm², respectively, when synthesized materials are using as a HTL material. The luminance efficiency of P-Cvz-3 is 20% higher than that of NPB, a commercialized HTL material used as a reference in this study.