The nanocrystalline TiO2 electrode of polythiophene sensitized solar cell was modified by coating gold nanoparticles with thermal decomposition method. The surface concentration of polythiophene adsorbed on TiO2 electrode was increased obviously due to the participation of gold nanoparticles. The interfacial charge transfer kinetics were investigated by analyzing of photocurrent action spectrum of polythiophene sensitized TiO2 electrode and fluorescence spectrum of polythiophene solution in the presence of TiO2 nanocrystals. After modification with Au nanoparticles, short circuit current of polythiophene sensitized solar cell increased from 2.68 mA cm (2) to 3.92 mA cm (2) and power conversion efficiency from 0.88% to 1.30% at AM 1.5. (C) 2008 Elsevier B.V. All rights reserved.