Bipolar Carrier Transport in a Lamello-Columnar Mesophase of a Sanidic Liquid Crystal

Abstract

The charge carrier transport property of the lamello-columnar mesophase of a [l}benzothieno[3,2-b][1]benzothiophene-2,7-dicarboxylate (BTBT) derivative was investigated by time-of-flight technique. BTBT exhibits a bipolar charge transporr, in the mesophase with comparable electron and hole mobility values in the order of 2×10^-3 cm² V^-1 s^-1. The high mobility values obtained for this disordered smectic phase can be explained by the improved π-overlap between lath-shaped aromatic moieties in the short-range columnar stackings.