InGaP//GaAs//c-Si 3-junction solar cells employing spectrum-splitting system

Abstract

In this work, we practically demonstrated spectrum-splitting approach for advances in efficiency of photovoltaic cells. Firstly, a-Si:H//c-Si 2-junction configuration was designed, which exhibited 24.4% efficiency with the spectrum splitting at 620nm. Then, we improved the top cell property by employing InGaP cells instead of the a-Si:H, resulting in an achievement of efficiency about 28.8%. In addition, we constructed 3-junction spectrum-splitting system with two optical splitters, and GaAs solar cells as middle cell. This InGaP//GaAs//c-Si architecture was found to deliver 30.9% conversion efficiency. Our splitting system includes convex lenses for light concentration about 10suns, which provided concentrated efficiency exceeding 33.0%. These results suggest that our demonstration of 3-junction spectrum-splitting approach can be a promising candidate for highly efficient photovoltaic technologies. Copyright (c) 2016 John Wiley & Sons, Ltd.