Evaluation of design and device parameters for lead-free SrPBr/SrNCl duel-layer perovskite photovoltaic device technology.

The study looks into how SrPBr and SrNCl double perovskite materials can be used as absorbers in perovskite solar cells (PSCs). Computational SrPBr and SrNCl simulations were employed to assess the performance of each absorber together with electron transport layers (ETL), with a particular emphasis on optimizing ETL thickness to improve charge transport and synchronize current outputs. The simulations yielded valuable insights into the electronic and optical characteristics of the individual absorbers. Subsequently, a tandem simulation was performed to adjust each layer's thickness, ensuring that both devices' current outputs were aligned for maximum system efficiency. The findings revealed that the tandem configuration of SrPBr and SrNCl surpassed the performance of the individual absorber setups, attributed to the optimized ETL thicknesses that enhanced charge transport and facilitated effective current matching. This study makes a significant contribution to the design and optimization of tandem PSCs utilizing SrPBr and SrNCl absorbers, paving the way for improved overall device efficiency. We investigated three device configurations to find the optimum structure. FTO/SnS/SrPBr/Ni, FTO/SnS/SrNCl/Ni, and FTO/SnS/SrPBr/SrNCl/Ni are considered as Device-I, II, and III. In Device-I, the execution parameters are power conversion efficiency (PCE) of 24.26%, an open-circuit voltage ( ) of 1.23 V, a short-circuit current density ( ) of 24.65 mA cm, and a fill factor (FF) of 87.42%. For Device-II, PCE, FF, , and are correspondingly 20.35%, 87.91%, 1.28 V, and 18.07 mA cm. The further refined tandem configuration achieved a PCE of 30.32%, with a of 1.27 V, an FF of 90.14%, and a of 26.44 mA cm, demonstrating the potential of this methodology in enhancing PSC performance.