Impedance Spectroscopy Analysis of Low-Cost mixed halide MAPbI1-xClx, Highly Efficient FAPbI3 and Non-Toxic Lead-free CsBi3I10 Perovskite Solar Cells: A Comparative Numerical Analysis using SCAPS-1D

Rapid development of Perovskite solar cells (PSCs) over the past few years, with significant improvement in efficiency from 3.8% to above 25% extended its research prospects in the emerging field of photovoltaics. Impedance Spectroscopy when applied to emerging photovoltaics presents new challenges towards potential device applications to the complex device structures of PSCs. In this work a comparative numerical analysis of three PSCs with ETL –TiO_2, HTL- Cu₂O and three different perovskites such as FAPbI₃, CsBi₃I₁₀ and MAPb (I_1-xCl_x) are studied using SCAPS-1D, a solar capacitance simulator that investigates performances of planar perovskite solar cells. The simulation studies by optimising the transport and active layer thickness, defect density and dopant concentrations, are done along with Impedance Spectroscopy analysis of all the three PSC structures. The simulation results prove that the mixed halide perovskite MAPb(I_1-xCl_x) (of PCE = 19.71%) outperforms the other active layers FAPbI₃ (PCE =22.04%) and CsBi₃I₁₀ (PCE=16.65%), since the Nyquist plot of MAPb(I_1-xCl_x), gives a more focussed and narrower spectrum of impedance values of the range 2K Ohm . The large diameter of Nyquist plot for FAPbI₃ and CsBi₃I₁₀ indicates a high resistance value of approximate 40K Ohm and 6K Ohm respectively, due to the processes like charge transfers at the interface, recombination and bulk internal material resistance. A simulation study was also done by including HTL –Spiro-OMETAD for the above three structures in the place of HTL-Cu₂O. From the above simulation results MAPb (I1_-xCl_x), proves to be one of the best perovskite absorber layer that can be utilized for perovskite solar cells.