Amorphous Conjugated Carbazole Trimers for Photorefractive Materials

New conjugated carbazole trimers for photorefractive materials have been synthesized by Pd-catalytic coupling reaction. These trimers were demonstrated to be amorphous by both differential scanning calorimeter and X-ray diffraction. In these carbazole trimers, three carbazole rings are π-conjugated through ethynyl group and act as a charge transporting agent. Peripheral carbazoles substituted with acceptor groups can be served as an electrooptic chromophore. The photoconductivity, electrooptic effect, and photorefractive properties of the conjugated carbazole trimer substituted with dicyanovinyl group doped with 2,4,7-trinitro-9-fluorenone as a sensitizer are reported.