A Numerical Simulation Study Investigating the Functionality of a Perovskite Solar Cell Based on FASnI3 in Both Conventional and Inverted Configurations Using Compatible Zn(O0.3S0.7) as the Electron Transport Layer

Formamidinium Tin Iodide is a promising candidate as an absorber layer in perovskite solar cells due to its tunable bandgap, high absorption coefficient, and good thermal stability. The selection of suitable charge transport layers providing the proper band offset can effectively reduce the recombination at the interfaces and improve the performance of solar cells. The study focuses on enhancing the performance of a perovskite solar cell in which Formamidinium Tin Iodide (FASnI3) is the absorber layer, Zn(O0.3S0.7) is the ETL and Spiro-OMeTAD is the HTL using numeric simulation. These charge transport layer materials are selected on the basis of their adequate energy band alignment with the absorber. The structure Glass substrate/FTO/Zn(O0.3S0.7)(ETL)/FASnI3/Spiro-OMeTAD(HTL)/Au, which is an unexplored combination in n-i-p architecture, is simulated through SCAPS-1D and optimization of cell parameters- absorber thickness, absorber doping concentration, absorber defect density, ETL thickness, ETL defect density, HTL thickness, and HTL defect density- is carried out. The variation of cell performance parameters with interface defect density and temperature is also analyzed. With this optimization, the cell delivers an open circuit voltage(Voc) = 1.0145V, short circuit current density (Jsc ) = 37.82mA cm-2, fill factor (FF) = 83.31% and Power Conversion Efficiency(PCE) =31.97%. The optimized parameters are used to simulate the p-i-n inverted architecture, and the cell output is as follows.Voc = 1.0919V, Jsc = 37.293mA cm-2, FF = 83.01% and Power Conversion Efficiency(PCE) =33.8%.