We report performance improvement of organic (P3HT:PCBM) photovoltaic cell by introducing a solution-based WO. anode buffer layer, between the PH500 conducting polymer and the active layer. By introducing a solution-based WOx on PH500, the cell efficiency increases by 13% compared to that of the organic photovoltaic cell with only PH500. The organic cell exhibits J(SC) of 12.31 mA/cm(2), V-OC of 0.61 V, FF of 58.22%, and the power conversion efficiency of 4.35%. The improved cell performance is due to effective hole collection injected from electron donors (P3HT) in P3HT:PCBM active layer by forming WOx, nanoparticle on the conducting anode. (C) 2011 Elsevier B.V. All rights reserved.