Carrier mobility of a columnar mesophase formed by a perfluoroalkylated triphenylene

The carrier mobility of a hexagonal columnar (Colh) mesophase was evaluated by a time-of-flight (TOF) technique for hexa(1H,1H,2H,2H3H,3H-perfluorononyloxy)triphenylenes (F6/C9). The photocurrent decay curves were clearly observed in the Colh mesophase to show an ambipolar nature and the carrier mobility is in the order of 10−4 cm2 V−1 s−1 for both positive and negative charges. The mobility is not of temperature-independent and three regions in temperature were recognized in which the activation energies are different to each, indicating different conditions of charge transports within the columnar structure are derived from the perfluoroalkyl chains. The comparison of temperature dependence to the corresponding non-fluorinated hexanonyloxytriphenylenes (C9OTP) indicates that the dynamical aspect of the peripheral chains profoundly affects that of the central triphenylenes in the segregated columnar structure.