Passivating Surface Defects and Reducing Interface Recombination in CuInS ₂ Solar Cells by a Facile Solution Treatment

Interface recombination at the absorber buffer interface impedes efficiency of a solar cell with an otherwise excellent absorber. The internal voltage or quasi-Fermi level splitting (qFLs) measures quality reduces open circuit (VOC) respect to qFLs. present work explores facile sulfur-based post-deposition treatment (S-PDT) passivate CuInS2 thin films grown under Cu-rich conditions, which show qFLs values, but much lower VOCs. absorbers are treated in three different S-containing solutions 80 oC. Absolute calibrated photoluminescence and current-voltage measurements demonstrate reduction deficit between VOC best S-PDT device by almost one third compared untreated device. Analysis temperature dependence open-circuit shows increased activation energy for dominant path, indicating less recombination. In addition, capacitance transient reveal presence slow metastable defects cell. response is considerably reduced S-PDT, suggesting passivation these defects. results effectiveness solution based S-treatment passivating defects, presenting promising strategy explore reduce defect states near chalcogenide semiconductors.