Optimisation of Silicon-Perovskite (MaPbI3) Tandem Photovoltaic Cell With a Tunnel Junction

Silicon-perovskite tandem photovoltaic cells are a promising approach to surpass the efficiency limits of singlejunction silicon solar cells. However, realistic modelling of twoterminal tandem architectures remains challenging because one-dimensional simulation tools such as SCAPS-1D do not inherently enforce the series current-matching condition between subcells and often fail to accurately capture bulk and interface defect-induced losses. This paper proposes a systematically optimised two-terminal silicon-perovskite tandem photovoltaic cell using SCAPS-1D. The proposed design includes a cost-effective ideal tunnel junction to reduce issues associated with current mismatch. A methylammonium lead iodide (MaPbI3) perovskite top subcell combined with a P-I-N silicon bottom subcell are independently optimised by systematically varying layer thicknesses and incorporating defect effects, enabling a realistic evaluation of practical device performance. The optimised designs achieved a maximum efficiency of 24.27 % for the silicon subcell, and 18.1 % efficiency for the perovskite subcell, while the combined tandem cell reached a realistic efficiency of 32.60-35.30%, significantly lower than the idealised 54.78 % estimate. These results demonstrate a practical methodology for evaluating siliconperovskite tandem architectures, highlighting the critical role of defect modelling, and provides insight into achievable performance limits, addressing gaps in current simulation approaches.