It is known that surface passivation plays a significant role in upgrading solar cell performance. In this study, silicon thin films deposited by LPCVD (low pressure chemical vapor deposition) are used to passivate the surface of solar-grade p-type crystalline silicon solar cells for the first time. Intrinsic amorphous silicon films and poly-silicon films were obtained on the front and rear surfaces of solar wafers at the deposition temperatures of 560 degrees C and 620 degrees C, respectively. Both kinds of silicon films proved to be effective in improving the open-circuit voltage owing to surface passivation for crystalline silicon solar cells. Optical spectral responses in the short and long wavelength ranges (e.g. the range 300-600 nm and the range 850-1100 nm, respectively) also showed an improvement in photogenerated current resulting from reduced surface recombination rates on the front and back surface. (c) 2012 Elsevier Ltd. All rights reserved.