In this work we present indium tin oxide free polymer photovoltaic devices featuring a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) anode that has been patterned by oxygen plasma etching. By optimizing the PEDOT:PSS formulation and thickness, we achieved conductivities up to 400 S/cm. The best overall power conversion efficiency was found to be 2.2% under equivalent illumination to one sun with a PEDOT:PSS film conductivity of 300 S/cm. (C) 2008 Elsevier B.V. All rights reserved.