Temperature- and Illumination-Dependent Characterization of Wide Bandgap Sulfide CIGS and CZTS Solar Cells

Photovoltaic devices are exposed to a wide range of temperatures and illumination conditions in the field. Using temperature-dependent current-voltage and Suns-VOC measurements, we investigate the performance of two types of wide-bandgap pure-sulfide inorganic thin film solar cells: CuInGaS2 (CIGS) and Cu2ZnSnS4 (CZTS). We find that both technologies behave linearly with temperature, with one-sun sensitivities close to that of crystalline silicon cells. In addition, we find that the open-circuit voltage of the investigated cells becomes significantly more sensitive to temperature at low light intensities as compared to one-sun. To our knowledge, these results are being presented for the first time, and we expect them to be instructional to the field and indoor yield prediction as well as tandem cell design.