Air-processed potassium doped CsSnBrCl₂ perovskite films for photovoltaic applications: an experimental and simulation study

Tin-based perovskites are increasingly gaining popularity as viable alternatives to lead-based perovskites due to their alluring photophysical characteristics and environmentally advantageous features. Regrettably, the commercial potential of tin-based perovskites is substantially constrained by their exceedingly poor stability and the absence of simple, low-cost synthesis options. Utilizing alkali metal cations such as potassium (K⁺) to modulate perovskite layers presents novel opportunities for developing high-performance inorganic perovskite solar cells (PSCs). This work reports a detailed study of the air-processed CsSnBrCl₂ perovskite films prepared via facile solution strategies. In addition, we investigated the influence of varied doping concentrations of potassium (K⁺) on the structure, morphological, photophysical, and photovoltaic features of CsSnBrCl₂ films. The prepared CsSnBrCl₂ perovskite exhibited outstanding air and thermal stability. The structural, morphological, and photophysical properties of the perovskite film were found to be boosted by K⁺ doping. The photovoltaic characteristics of PSCs formed from undoped and doped photoactive layers were compared using SCAPS-1D, and the doped systems were found to possess substantial improvements in the photovoltaic characteristics. This investigation introduces a practical and efficient method for enhancing the photovoltaic performance and properties of Sn-based PSCs.