DEVICE MODELLING AND OPTIMIZATION OF LEAD-FREE (NH4)3SB2I9 PEROVSKITE SOLAR CELLS BY USING SCAPS-1D

Abstract

As commercialization and industrial growth continue to accelerate, the demand for power and energy is rising steadily. Growing energy needs can be responsibly met while protecting the environment for coming generations by using renewable energy. With proper harvesting, solar power becomes not just viable—but one of the most effective renewable energy options. This makes it crucial to enhance solar technologies that are both high-performing and safe for the environment. Advancing lead-free perovskite solar cells (PCSs) is essential for developing sustainable and eco-friendly solar technologies. These alternatives to lead-based free PSCs offer notable benefits, including low cost, excellent stability and promising efficiency positioning them as attractive candidates for next-generation photovoltaic applications. Among the emerging materials, (NH4)3Sb2I9 stands out due to its favourable optoelectronic properties and environmental safety. This study investigates the impact of different HTLs and ETLs on the performance of a (NH4)3Sb2I9-based device using SCAPS-1D software. Several parameters influencing device efficiency were optimised, including thickness of absorber layer, operating temperature, work function of back contact, donor density, defect density (Nt), series and shunt resistance. The optimized device structure FTO/WS2/(NH4)3Sb2I9/MASnBr3/Au achieved a PCE of 20.08 % (with a VOC of 1.65 V, JSC of 13.83 mA/cm2 and FF of 87.93 %) at 300 K and Nt of 1013 cm-3 . These results demonstrate the strong potential of antimony-based perovskites in the development of high-performance, lead-free solar cells.