InGaN/GaN multiple-quantum-well solar cells were grown on (111) Si substrates. AIN/AlGaN superlattice and self-assembly SixNy masking islands were employed to alleviate the material mismatches between Si and GaN. The devices were characterized under the illumination of AM 1.5 G with different solar concentrations. As the concentration ratios increased from 1-sun to 105-sun, energy conversion efficiency was enhanced by 25%, which was noticeably greater than the enhancement reported on sapphire substrates under similar solar concentrations. The result is attributed to the superior heat sinking of Si substrates. (C) 2013 Elsevier B.V. All rights reserved.