Numerical Optimization of Wide Bandgap Perovskite With Various Bottom Cell Absorber for Tandem Solar Cell Applications

Abstract

Recently, single-junction perovskite solar cells (PSCs) have demonstrated significant improvements in performance. In addition to their strong performance, PSCs are particularly attractive for tandem integration with other photovoltaic technologies such as silicon, copper indium gallium selenide (CIGS), narrow-bandgap perovskites (NBG), organic, and CdTe solar cells, where their tunable bandgap enables more efficient utilization of the solar spectrum and the potential for enhanced overall device efficiency. Herein, a systematic investigation is presented to maximize the efficiency of tandem architectures through careful selection of the bandgaps of the top and bottom subcells and optimization of interfacial engineering aspects. The optimized wide-bandgap (WBG) perovskite top subcell exhibits a power conversion efficiency (PCE) of 23.73%, with an open-circuit voltage of 1.26 V, short-circuit current density of 21.64 mA cm⁻², and fill factor of 86.92% obtained through systematic optimization of charge transport layers, absorber thickness, and defect engineering. Integration into tandem configurations reveals that appropriate bandgap selection and current matching enable efficiencies of 35.38% (Perovskite/Si), 33.69% (Perovskite/CIGS), and 36.15% (All-perovskite). The simulation results indicate that the proposed optimization strategy can improve the performance potential of the WBG perovskite top cell for tandem applications.