19·9%-efficient ZnO/CdS/CuInGaSe 2 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.