Transparent electrodes based on PEDOT were prepared using a variety of techniques suitable for large area applications from 3,4-ethylenedioxythiophene (EDT) and Fe(111)tosylate. High conductivities were obtained (similar to 20 Omega(-1)) with moderate transmission in the UVvisible range 350-600 nm. We subsequently demonstrate the application of PEDOT electrodes to flexible polyethyleneterphthalate plastic substrates (PET) prepared by this procedure for polymer photovoltaic devices with active areas of 4.2cm(2) using a 1:4 w/w mixture of MEHPPV and PCBM. We obtain typical efficiencies of 0.2% under simulated sunlight (AM1.5 at 1000 Wm(-2)). (c) 2005 Elsevier B.V. All rights reserved.