Improved performance in ZnO/CdS/CuGaSe2 thin-film solar cells

We report the growth and characterization of improved efficiency wide‐bandgap ZnO/CdS/CuGaSe2 thin‐film solar cells. The CuGaSe2 absorber thickness was intentionally decreased to better match depletion widths indicated by drive‐level capacitance profiling data. A total‐area efficiency of 9·5% was achieved with a fill factor of 70·8% and a Voc of 910 mV.