Transient photoconductivity in a discotic liquid crystal

Using a time-of-flight technique, different transport mechanisms, deep trapping, multiple shallow trapping, and ideal itrinsic transport, can be observed in the different temperature and phase regions of the liquid-crystalline photoconductor hexapentyloxytriphenylene. The temperature and field dependences of carrier mobilities up to 1×{}10^-3 cm²/V s have been determined; this value exceeds considerably the mobilities of the most commonly used organic photoconductors. The experiments reflect a variety of transport phenomena which are novel in the field of liquid-crystalline systems.