Zinc oxide nanorod arrays hydrothermally grown on a highly conductive polymer for inverted polymer solar cells

We present fully solution processable hybrid electrodes comprising highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) layers and hydrothermally grown zinc oxide nanorods. These electrodes exhibit conductivities of about 1400 S/cm and a transmittance of more than 80%. By incorporating these electrodes into inverted polymer photovoltaic devices, power conversion efficiencies of 1.6% are achieved. Charge carrier lifetime measurements by means of impedance spectroscopy indicate an improved charge carrier extraction from the device upon the incorporation of the nanorod array.