SCAPS-1D Modeling and Multi-Parameter Optimization of a CABTSe/MASnI3 DoubleAbsorber Lead-Free Solar Cell

This study reports the first systematic, multi-parameter co-optimization of a lead-free double-absorber solar cell (DASC), jointly tuning ETL selection, absorber thickness, acceptor doping, temperature, and back-contact work function within a single CABTSe (CuAgBeSnSe4)/MASnI3 device architecture—an integrated approach that prior DASC studies had not addressed, since earlier work optimized these parameters individually rather than in combination. Using SCAPS-1D numerical simulation, we screened six ETL materials (WS2, SnS2, ZnSe, ZnO, PCBM, and TiO2) against a Zn3P2 hole transport layer and identified SnS2 as the optimal ETL,the optimal FTO/SnS2/CABTSe/MASnI3/Zn3P2/Au architecture, achieving 32.53% power conversion efficiency (PCE), while acceptor-doping optimization alone yielded 38.26% PCE, providing practical design guidelines for high-efficiency, environmentally friendly next-generation photovoltaic devices.