Damage gettering of undesirable impurities is attempted for crystalline wafers grown from commercial and refined metallurgical-grade silicon. The feasibility of impurity gettering is investigated by fabricating diffused solar cells and evaluating the photovoltaic characteristics. In an O2 annealing, the fill factor of solar cells decreases to 0.25 due to junction leakage, while the factor is drastically improved by annealing in N2. A maximum conversion efficiency is attained to be 9.1% for single crystals grown from refined metallurgical-grade source. Dark current-voltage characteristics are investigated by preparing small-sized diodes into gettered wafers. It is found that damage gettering affects the remarkable reduction of junction leakage and also enhances minority carrier lifetimes in the bulk crystals.