A series of novel porphyrin-grafted poly (phenylene vinylene) derivatives, Porp-RO-PPV, were synthesized by a simple two-step method. These copolymers contain conjugated poly(phenylene vinylene) derivatives as polymer backbone and covalently linked porphyrin units as side chain, which were confirmed by FTIR and H-1 NMR, and used for photovoltaic devices. The thermal, optical properties and sensitizing effect, and photovoltaic properties have been investigated. The emission spectra of Porp-RO-PPV copolymers revealed the existence of strong energy transfer from PPV backbone to porphyrin units. The energy conversion efficiency (eta(e),) of photovoltaic devices based on Porp-RO-PPV+PCBM reached 0.33% (78.2 mW/cm(2), AMI.5) and porphyrin units in the copolymers showed good sensitizing effect at low concentration. (c) 2008 Wiley Periodicals, Inc.