We report the charge conduction behaviours and photovoltaic properties of two different diodes containing low-molecular-weight organic semiconductors: N,N'-Di-[(1-naphthyl)-N,N'-diphenyl]-1,1'-biphenyl)-4,4'-diamine (NPD) and tris[4-(5-dicyanomethylidenemethyl-2-thienyl)phenyl]amine (TDCV-TPA), respectively. Both low-molecular-weight materials were triphenyl-amine TPA derivatives, and each thin film was sandwiched between indium tin oxide (ITO) and aluminium (Al) electrodes. In our work, the NPD and TDCV-TPA thin films were prepared via a solution-processed spin-coating technique instead of the conventional method of thermal evaporation. Higher electrical conduction and photocurrents were produced by utilizing a TDCV-TPA layer in the device instead of an NPD film. We attribute such phenomena to the greater carrier mobility and to the increase in charge generation. (C) 2011 Elsevier B.V. All rights reserved.