All-perovskite two-terminal tandem solar cell with 32.3% efficiency by numerical simulation

Metal halide all-perovskite tandem solar cell has shown great promise with enhanced power conversion efficiency beyond the limitation of a single junction cell. In this work, we have simulated all-perovskite tandem solar cells with a top cell of 1.75 eV wide-bandgap FA0.8Cs0.2Pb(I0.7Br0.3)3 and bottom cell with 1.25 eV (FASnI3)0.6(MAPbI3)0.4:Cl as main perovskite absorber materials through simulation on SCAPS-1D software. The simulated device shows an almost 13% higher power conversion efficiency value as compared to the experimentally achieved value in identical device configuration with the same materials. In addition to this, almost 54% increment in the power conversion efficiency to around 32.3% is achieved after simulating the improved tandem configuration gained from varying various transport layers along with alteration in their layer thicknesses. Decreased device resistance, easy transportation mechanism of charge carrier, along with defect-controlled simulation, has assisted in such a significant increase. This work provides a new direction for experimental realization with higher power conversion efficiency and establishes a new route toward the development of all-perovskite tandem solar cells.