Air‐Stable Solar Cells with 0.7 V Open‐Circuit Voltage Using Selenized Antimony Sulfide Absorbers Prepared by Hydrazine‐Free Solution Method

Abstract

Antimony chalcogenide is a promising absorber material for photovoltaic (PV) cells because of its tunable band gap, strong optical absorption, earth‐abundant, and nontoxic constituents. Here, a novel hydrazine‐free approach for fabricating antimony chalcogenide films prepared via spray pyrolysis deposition with further selenylation, as well as high performance solar cells are reported. The fabricated antimony chalcogenide solar cells exhibits remarkably high open‐circuit voltage (VOC) comparing with that of Sb2Se3 and Sb2S3 devices. The distribution of Se during the selenylation process via refering to the Fick's second law is discussed. The results show that the selenized absorber has tremendously improved absorbance for visible light and a cascade‐type energy level from surface to bulk, resulting in an ideal energy level matching for p‐n junction. By introducing an efficient buffer layer, the detrimental short‐circuit is avoided by reducing the cracks. Finally, 4.57% of the power conversion efficiency (PCE) of the solar cell is achieved. Furthermore, a module with a large‐scale active area of 21 cm2 is successfully fabricated, which shows a PCE of 3.19%, and a VOC of 3.42 V. The present work suggests that the antimony chalcogenide solar cells are promising for industrial application.