Charge transport properties of a metal-free phthalocyanine discotic liquid crystal

Discotic liquid crystals can self-align to form one-dimensional semiconducting wires, many tens of microns long. In this letter, we describe the preparation of semiconducting films where the stacking direction of the disc-like molecules is perpendicular to the substrate surface. We present measurements of the charge carrier mobility, applying temperature-dependent time-of-flight transient photoconductivity, space-charge limited current measurements, and field-effect mobility measurements. We provide experimental verification of the highly anisotropic nature of semiconducting films of discotic liquid crystals, with charge carrier mobilities of up to 2.8 x 10(-3) cm(2)/V s. These properties make discotics an interesting choice for applications such as organic photovoltaics. (c) 2006 Elsevier B.V. All rights reserved.