Lead-free All-perovskite Tandem Solar Cell

This talk will present our simulation results of a lead-free all-perovskite tandem solar cell obtained with the SCAPS-1D simulation tool. The cell model was calibrated with experimental data of the perovskite cell. First, the top and bottom subcells, consisting of MAGeI₃, and FASnI₃, respectively, were optimized individually by varying material properties such as thickness, electron affinity, and capture cross-section. These standalone optimized subcells are then utilized for the tandem structure. The optimal tandem cell thickness was determined based on short circuit current density (J_SC) matching of the standalone subcells by varying the subcells’ thickness. A matching J_SC of 14.70 mA/cm² was obtained for the top and bottom subcell thickness of 983 nm and 1600 nm, respectively. At this current matching condition, the simulation shows that a tandem cell would yield a high open-circuit voltage (V_OC) of 2.63 V, resulting in an efficiency of 30.85%, significantly higher than that of each cell.