Charge Carrier Transport Properties in Liquid Crystalline 2-Phenylbenzothiazole Derivatives

We synthesized liquid crystalline 2-phenylbenzothiazole derivatives and investigated their charge carrier transport properties by time-of-flight experiments. These materials show less ordered phases such as smectic A, smectic C, and nematic phases at temperature range lower than 100 degrees C, and their mobility was relatively small, from 10-5cm2/Vs to 10-4cm2/Vs. In addition, the mobility depends on temperature, while it did not depend on electric fields. According to these results, we estimated the eneregy distribution of density of states responsible for condition, sigma of Gaussian width, to be 78118meV.