Simulated annealing algorithm-assisted SCAPS-1D design enables 27.04 % efficiency in dual-absorber perovskite solar cells

Perovskite solar cells (PSCs) are redefining the trade-off between cost and performance in photovoltaic technologies, owing to their high optical absorption coefficients and compatibility with low-temperature solution processing. In this study, a dual-absorber PSC architecture is developed utilizing CsBi₃I₁₀ (CBI) and Cs₂SnI₆ (CSI), selected for their intrinsic stability and low toxicity, achieving an initial power conversion efficiency (PCE) of 12.50 %. The suitability of the charge transport layers is assessed through analysis of valence and conduction band alignments, complemented by a detailed examination of the optical absorption characteristics of each functional layer. To enhance device performance, a hybrid optimization approach combining SCAPS-1D with a simulated annealing algorithm (SAA) is employed to fine-tune the thicknesses of both absorber and transport layers. Stepwise regression is leveraged to construct the objective function for SAA, enabling multivariate optimization and overcoming the conventional SCAPS-1D limitation to single-variable tuning. Following this optimization, the PCE improves to 15.75 %, with performance metrics closely matching simulation predictions. Further refinements in absorber properties—specifically interface trap density, bandgap, carrier concentration, and bulk trap levels—push the simulated PCE to 30.45 %. Subsequently, the PCE was adjusted to 27.04 % through the incorporation of discussions on resistance and illumination intensity, with the further evaluated under varying operational conditions, including temperature, spectral distribution, and capacitance. The dual-absorber configuration significantly extends the spectral response and facilitates efficient charge transport. Conversely, low shunt resistance should be circumvented to mitigate performance degradation.