Numerical analysis of the optoelectronic properties of selected Sn-based perovskites solar cells using SCAPS simulation

Abstract

Halide-perovskite solar cells are gaining popularity and could significantly impact the development of next-generation solar cells. However, one of the biggest obstacles to the commercialization of perovskite solar cells is the toxic nature of lead (Pb), which is the primary component of the most efficient absorber layer. Consequently, the necessity to replace the toxic Pb in the perovskite solar cell business is driving an increase in research interest in Pb-free perovskite solar cells. A number of Pb-free perovskites, including Ge-, Sb-, Sn-, and Bi-based perovskites, have emerged to offer a solution. Nonetheless, prior research has demonstrated that Sn-based perovskite solar cells are promising alternatives to lead-based solar cells. However, the main disadvantages are its poor power conversion efficiency and stability issues. To overcome its intrinsic shortcomings, it is critical to investigate scientific possibilities for optimizing its internal mechanism.

This study is a theoretical simulation of five selected Sn-based perovskites (MASnBr₃, FASnI₃, CsSnI₃, MASnI₃, and CsSnCl₃) in a multiple ETLs architecture (specifically, p-n-n architecture) with the use of the SCAP 1D simulator to optimise some material properties towards improved PV parameters. The study showed that careful optimisation of electrical and optical parameters and proper choice of architecture are essential towards achieving highly efficient perovskite solar cells. The choice of p-i-n-n architecture with ITO/P3HT/Perovskite layer/PCBM/WS2/Au structure was intentional in order to create innovation and also to strategically enhance the efficiency of the device. The thickness of the charge transport layers in this structure, the percent transparency of the front electrode, and the donor/acceptor doping concentration of the charge transport layers were first optimized. Then the five active layer thicknesses were individually optimised in this same structure, and a comparative numerical analysis of the performance parameters of the five materials was carefully carried out using the outcomes from SCAPS 1D software. After all, the FASnI₃ absorber material shows the highest performance with a power conversion efficiency (PCE) of 6.06 %, a Voc of 1.37 V, a JSC of 5.25 mA/cm², and an FF of 84.1 % among the selected Sn-based perovskite solar cells investigated.