Three kinds of important properties of the solar cell were calculated: short-circuit current density, open-circuit voltage, and conversion efficiency. Two equations which show the relationship between the minority-carrier diffusion length and the grain size or the etch pit density were used for the calculation. The dependence of the properties on the cell thickness were estimated as a function of grain size and etch-pit density. The effect of the internal reflectance with varying minority-carrier diffusion length was also examined. The results show that thin film polycrystalline silicon solar cells have the potential to attain an efficiency of 17&percent; even at a film thickness of 2 &mgr;m if the grain size is bigger than 10 &mgr;m and the etch-pit density of less than1×106 cm−2.The principal requirement is to achieve efficient light trapping. ©1997 American Institute of Physics.