Abstract
Self-organizing molecular semiconductors, which enjoy interesting natures of both of the liquid crystal and the organic semiconductor, exhibit excellent carrier transport properties characterized by a fast ambipolar mobility up to the order of 10^<-2> cm^2/Vs due to the molecular orientation in self-alignment manner. In contrast to the conventional amorphous semiconductor, electronic and/or optical anisotropy is one of unique natures of this type of materials. We studied the anisotropy with planer-structured devices consisting of the finger-type electrodes, in which the organic semiconductor is homogeneously aligned. We prepared different samples where the organic semiconductor was oriented to parallel, perpendicular, or random to the electrodes. In any case, no molecular orientation layer was applied to avoid additional effect of the layer on carrier injection. We measured steady and transient dark/photo currents in different mesophases. As a result, obvious conductive anisotropy was observed. The maximum currents ratio under the same field intensity reaches 10:1 according to the molecular orientation.
