Design and numerical simulation of B‑γ CsSnI3‑based perovskite solar cells: Conventional versus inverted configurations

•This research utilizes SCAPS for an in-depth simulation study on B-γ CsSnI3 perovskite solar cells (PSCs).•A calibration step of the simulation model against fabricated B-γ CsSnI3 cell enables accurate validation of the simulation model.•Both inverted (n-i-p) and conventional (p-i-n) cell configurations are explored,•Optimizations achieved PCEs of 16.11% and 13.76% for p-i-n and n-i-p structures, respectively.•The study provides valuable insights into improving PSC efficiency by adjusting band alignments, optimizing back contact work functions, and considering HTL and ETL-free structures. This paper introduces a thorough simulation study, based on SCAPS, into the realm of B-γ CsSnI3 perovskite solar cells (PSCs). The work encompasses an array of critical aspects ranging from material properties to device physics strategies and performance enhancement techniques. The core objective of this study revolves around the meticulous optimization of device performance, primarily through the enrichment and enhancement of the absorber layer. The intricate energy band alignment between photoactive layer and carrier transportation layers emerges as a key focus, prompting a systematic exploration of alternative materials. The study begins by validating the simulation models and parameters via performing a device modeling calibration versus an experimental p-i-n B-γ CsSnI3-based PSC with an efficiency of 10.10%. Next, both inverted (n-i-p) and conventional (p-i-n) cell configurations are considered, allowing for a comprehensive evaluation of their potential. The p-i-n configuration is optimized through investigating the band alignment between the hole transportation layer (HTL) and the absorber, achieving a power conversion efficiency (PCE) of 16.11%, and 14.55% in the ETL-free configuration after adjusting the rear contact metal work function. Similarly, it is shown that the n-i-p structure can achieve a PCE of 13.76% after optimizing the electron transportation layer (ETL), while upon optimizing the back contact work function led to a maximum PCE of 21.47% for the HTL-free structure. By delving into these multifaceted dimensions, this research contributes not only to the advancement of B-γ CsSnI3-based PSCs but also provides valuable insights into the most promising avenues for achieving elevated efficiency.