Until recently, chalcopyrite-based solar cells have achieved a maximum energy conversion efficiency of 23.35%, as reported in 2019 by Solar Frontier, a former Solar Energy company based in Japan. Further boosting this efficiency, however, has so far proved challenging.
Researchers at Uppsala University and at the First Solar European Technology Center AB (former Evolar AB) in Sweden recently attained a higher efficiency of 23.64% in chalcopyrite-based solar cells. This efficiency, reported in Nature Energy, was achieved using two primary techniques, namely high-concentration silver alloying and steep back-contact gallium grading.
“A primary objective of our study was to increase the efficiency of CIGS-based thin-film solar cells to ultimately lower the price per Watt-peak of corresponding large-scale modules,” Jan Keller, first author of the paper, told Phys.org. “Our work makes use of the findings from many research groups around the world, obtained during the last decades.”