Investigating the performance of formamidinium tin-based perovskite solar cell by SCAPS device simulation

Tin-based perovskite is a famous competitor to toxic lead-based perovskite solar cells. Although lead-free perovskite (CH3NH3SnI3) material attracts the attention because of its wider absorption, it suffers from temperature instability. Formamidinium tin iodide (HC(NH2)(2)SnI3-FASnI(3)) absorber has more temperature stability than CH3NH3SnI3 with wider band gap (1.41 eV). In this work, a device simulation of FASnI(3)-based solar cells is performed by using SCAPS. Absorber parameters such as thickness, doping concentration and defect density are varied to inspect their impact on device performance. The effect of changing conduction band offset (CBO) and valence band offset (VBO), doping concentration and thickness of electron transport layer (ETL) and hole transport layer (HTL) are also studied. Further, various HTL and ETL candidates are investigated such as CuI, Cu2O, NiO, ZnO and ZnSe. To enhance the cell power efficiency, optimization of the device design key parameters is performed. The initial structure is based on an experimental work having a record of 1.75% efficiency. The final performance parameters of the intended solar cell after enhancing them by the presented parametric study are found to be: a short-circuit current density (J(sc)) of 22.65 mA/cm(2), open-circuit voltage (V-oc) of 0.92 V, fill factor (FF) of 67.74% and power conversion efficiency (PCE) of 14.03%.