Fast Hole Transport in a New Calamitic Liquid Crystal of 2-(4′-Heptyloxyphenyl)-6-Dodecylthiobenzothiazole

The carrier transport in different phases of a new photoconductive calamitic liquid crystal, 2-(4{'}-heptyloxyphenyl)-6-dodecylthiobenzothiazole was studied by the time-of-flight technique: In the smectic A phase, a fast hole transient photocurrent was obtained in a nondispersive manner, in which the mobility was as high as 5×10^-30ex0excm²/Vs and independent of applied electric field; in the isotropic phase, however, slower carrier transport was observed, probably due to positive or negative ions, and their mobilities were as low as 10^-50ex0excm²/Vs. These experimental results demonstrate the importance of local molecular alignment in creating the fast electronic conduction in calamitic liquid crystals.