Carbazolyl- and diphenylamino substituted fluorenes as hole transport materials

Four fluorene-containing aromatic amines with carbazole and diphenylamine moieties were synthesized by Ullmann coupling. Comparative study on their thermal, optical and photoelectrical properties is presented. One synthesized compound is found to form glass with the glass transition temperature 58 °C as characterized by differential scanning calorimetry. The ionization potentials established by electron photoemission technique are in the range 5.9–6.1 eV. Hole-drift mobilities of 50% solid solution of 2,7-dicarbazolyl-9,9-dihexylfluorene in bisphenol Z polycarbonate established by the xerographic time-of-flight technique exceed 10−4 cm2 V−1 s−1 at electric field of 106 V cm−1.