We have adopted an appropriate HNO3-HF-H2O mixed solution to smooth the surface of the silicon wafer. The solution evidently reduces the surface roughness of double-side chemical polished c-Si, and the interface state density (D-it) decreases from 10(11) cm(-2) eV(-1) to 10(10) cm(-2) eV(-1) at the mid-gap energy level. Therefore the effective minority carrier lifetime (tau(eff)) of silicon wafer increases from 259 us to 273 us. Replace it with textured c-Si, the weighted reflectance of silicon increases to 15.9% from 11.97%; and tau(eff) is also up to the highest value of 437 us at 1000 s from 221 us of as-prepared textured silicon.