19.9%-efficient ZnO/CdS/CuInGaSe2 solar cell with 81.2% fill factor

We report a new record total-area efficiency of 19.9% for CuInGaSe2-based thin-film solar cells. Improved performance is due to higher fill factor. The device was made by three-stage co-evaporation with a modified surface termination. Growth conditions, device analysis, and basic film characterization are presented. Published in 2008 by John Wiley & Sons, Ltd.