Photorefractive properties of bifunctional N-arylated carbazole derivatives in a carbazole polymer host matrix Original Research Article

We report on the synthesis and the molecular properties of new N-arylated carbazole derivatives that are used as bifunctional chromophores in photorefractive (PR) polymer composites. The C–N bond of the N-aryl carbazole chromophore was formed directly by a nucleophilic aromatic substitution and Ullmann type coupling of carbazole with aryl halides. We performed calculations on the molecular conformation, the magnitude of the dipole moment and the linear polarizability tensor and their relative orientation. The PR performance of the chromophores, doped in an inert polymer host matrix and in a carbazole matrix, with C60 as sensitizer, was evaluated using four-wave mixing experiments and photoconductivity measurements at 680 nm. The impact of the relative orientation of dipole moment and polarizability tensor on the Figure-Of-Merit (FOM) of photorefractive experiments was clearly demonstrated.