Performance enhancement of eco-friendly Cs3Sb2I9-based perovskite solar cell employing Nb2O5 and CuI as efficient charge transport layers

The marketing of perovskite solar cells (PSCs) as an eco-friendly energy source can help with carbon footprint lowering. However, the traditional lead cation-based perovskites represent a concern to the environment due to the inclusion of lead. Life forms that are physically close to lead sources face a wide range of harmful effects. Owing to its excellent electrical arrangement and non-toxic quality, antimony (Sb) is frequently regarded as one of the potential lead substitutes. Herein, using SCAPS-1D software, we investigated the photovoltaic performance of Cs3Sb2I9-based solar cells employing Nb2O5 and CuI as efficient charge transport layers (CTLs). Thickness, doping, and band alignment of the absorber and both CTLs are thoroughly investigated. Besides, it has been studied how defects at the ETL/absorber and absorber/HTL interfaces as well as defects in the absorber's bulk might affect photovoltaic performance. In Addition, back contact properties are optimized to gain the best ohmic configuration to improve the collection mechanism. The optimized device presents an efficiency of 12.03% with a short-circuit current density of 10.57 mA/cm2, an open-circuit voltage of 1.37 V, and a fill factor of 82.63%. This simulation's results will facilitate the researchers to choose the appropriate CTLs for solar cells, which will demonstrate increased tolerance against interface defects by achieving optimal interface band alignment. These results will also be useful for determining the ideal values for defect parameters in a variety of real PSCs.