Here, we elucidate the influence of active layer thickness and defect density on the photovoltaic performance of lead-free CsSn_0.5Ge_0.5I₃ perovskite solar cells (PSCs). We explained the dependence of FF and J_SC on the perovskite layer thickness and defect density in terms of the extraction rate and generation rate, identifying the role of charge extraction and recombination in the operation of perovskite solar cells. Our finding revealed that when active layer thickness was varied, the best performance was achieved with a thickness of 0.4 µm, resulting in a PCE of 12.79%, open circuit voltage (V_OC) of 0.807 V, FF of 77.42%, and J_SC of 20.47 mA/cm² for the CsSn_0.5Ge_0.5I₃-based PSC. Additionally, the impact of defect density on PSC performance was assessed using the Shockley–Read–Hall recombination model. The degradation of photovoltaic performance was evident as trap density increased, with the PCE dropping from 14.38 to 5.47%. V_OC experienced a significant reduction of 40%, while J_SC and FF showed drops of 25.3% and 14.6%, respectively. The study emphasizes the importance of optimizing active layer thickness and minimizing trap densities to enhance the performance of lead-free PSCs.

在这里，我们阐明了活性层厚度和缺陷密度对无铅CsSn _0.5 Ge _0.5 I ₃钙钛矿太阳能电池（PSC）光伏性能的影响。_{我们从提取率和生成率方面解释了 FF 和 J SC}对钙钛矿层厚度和缺陷密度的依赖性，确定了电荷提取和复合在钙钛矿太阳能电池运行中的作用。我们的发现表明，当有源层厚度变化时，厚度为 0.4 µm 时可获得最佳性能，PCE 为 12.79%，开路电压 (V _OC ) 为 0.807 V，FF 为 77.42%，J _SC对于基于CsSn _0.5 Ge _0.5 I ₃的PSC ，电流为20.47 mA/cm ²。此外，还使用 ​​Shockley-Read-Hall 复合模型评估了缺陷密度对 PSC 性能的影响。随着陷阱密度的增加，光伏性能明显下降，PCE从14.38%下降到5.47%。VOC显着降低了 40%，而 J _SC和 FF 分别下降了 25.3% 和 14.6% _。该研究强调了优化有源层厚度和最小化陷阱密度以增强无铅 PSC 性能的重要性。