We have fabricated P3HT/PCBM based bulk-heterojunction photovoltaic cells with P3HT layer as the hole transport layer and PCBM layer as the electron transport layer between electrode and blended P3HT/PCBM layer in order to widen the photon harvesting layer. Current density has increased by about 1 mA/cm(2) by the insertion of P3HT layer and the resulting conversion efficiency has been improved by about 20%. We have also fabricated a centimeter-scale active area with an efficiency of similar to 1%. Crown Copyright (c) 2010 Published by Elsevier B.V. All rights reserved.