Advances in lead-free perovskite solar cell design via SCAPS-1D simulations

Abstract

Perovskite solar cells (PSCs) have attracted significant attention over the past decade due to their high performance. However, challenges such as moisture sensitivity and the toxicity of certain constituents remain barriers to their commercialization. Tin, germanium, and other elements with optoelectronic properties similar to those of lead have emerged as promising substitutes for the B-site metal in PSCs. Theoretical studies have played a crucial role in elucidating how specific material and structural parameters influence photovoltaic behavior. Among the most prominent tools for simulating thin-film solar cells in recent years, open-source SCAPS-1D software stands out as a valuable resource. Therefore, this article presents a comprehensive review of 54 simulation studies, using SCAPS-1D, published between 2016 and 2025, focusing on lead-free PSCs. In total, 26 studies on Sn-based PSCs and 28 on perovskites with alternative B-site metals were analyzed to evaluate how simulations have contributed to understanding device performance with lead substitutes. This review also provides an overview of the current research landscape and highlights promising directions for advancing environmentally benign, lead-free PSCs through SCAPS modeling. The studies discussed in this review show a prevailing tendency to simulate PSCs in regular rather than inverted configuration. In many cases, the defect density assumed for the absorber layer is set at ideal values or even below 10¹³ cm⁻³, which potentially limits the accuracy of predictions. Among the strategies adopted to improve performance, composition engineering emerged as the most prominent.