Effect of ABX ₃ site changes on the performance of tin–lead mixed perovskite solar cells

Tin-lead mixed perovskite solar cells (TLMPSCs), with the advantage of approaching the Shockley-Queisser (S-Q) limit for photovoltaic applications, have been rapidly developed and achieved a power conversion efficiency (PCE) of 23.7%. Although the low toxicity of TLMPSCs is conducive to sustainable development, the oxidation of Sn²⁺ could destroy the perovskite structure easily. Thus, most researchers are devoted to improving the photoelectric performance and stability through additive engineering, interface engineering, device structure optimization, solvent engineering, etc. However, TLMPs with different A-sites and X-sites in the ABX₃ model and an optimal ratio of Sn : Pb still need to be investigated; this is the basis of mechanistic analysis. In this paper, we introduce TLMPSCs with different A-sites, X-sites, and Sn-Pb ratios. The mechanism and properties of the cations are analyzed based on the performance of TLMPSCs. Finally, a series of prospects for optimizing ABX₃ are put forward, with the hope of attracting the attention and interest of researchers.