Photophysical studies and photovoltaic devices on a low bandgap, high-charge carrier mobility poly(thienylene vinylene) (PTV), prepared from a soluble precursor polymer synthesised via the "dithiocarbamate route", are reported. In composites with an electron acceptor ([6,6]-phenyl C-61-butyric acid methyl ester (PCBM), a soluble fullerene derivative), photoinduced absorption characteristic for charged excitations together with photoluminescence quenching are observed indicating photoinduced electron transfer. The "bulk heterojunction" photovoltaic devices using PTV and PCBM composites show short-circuit currents up to 4 mA/cm(2) under AM 1.5 white-light illumination. The photocurrent spectrum of the photovoltaic device shows an onset about 1.65eV (750nm), which corresponds to the absorption spectrum of the polymer. (c) 2006 Elsevier B.V. All rights reserved.