This Letter reports the determination of the singlet exciton diffusion length (L-D) for a thermotropic discotic columnar liquid crystal (CLC) in both non-oriented and homeotropically oriented (columns perpendicular to the substrate) samples. Experimental results based on photoluminescence measurements indicate that L-D is only slightly dependent on the liquid crystal orientation. Conversely, studies of ITO/CLC (50 nm)/Al Schottky-type devices formed by non-oriented and oriented liquid-crystalline films show an increase in the photocurrent by a factor of 16, due to the homeotropic alignment. This improvement is attributed to both increased light absorption and charge-carrier mobility. (C) 2009 Elsevier B.V. All rights reserved.