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 x 10(-3) cm(2)/V s 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(-5) cm(2)/V s. These experimental results demonstrate the importance of local molecular alignment in creating the fast electronic conduction in calamitic liquid crystals.