First electronic conduction with high hole mobility in smectic A phase of a calamitic liquid crystal

Liquid crystalline photoconductor 2-(4'-heptyloxyphenyl)-6-dodecylthiobenzothiazole was designed and its carder transport characteristics was measured with Time-of-Flight (TOF) technique. In crystal state, only transient current decay originating from a capturing process of photo-generated carriers by deep traps formed at grain boundaries was observed. Ln smectic A (SmA) phase, non-dispersive transient photocurrent based on fast hole transport was observed, in which hole mobility was 5 X 10(-3) cm/Vs, independent of electric field. In isotropic phase, ambipolar transport proceeded and tie mobilities of both positive charge and negative charge carriers were on the order of 10(-5) cm(2)/Vs.