Tin (Sn) halide perovskite has been a promising candidate in lead-free perovskite solar cells (PSCs), but its chemical instability attributed to Sn²⁺/Sn⁴⁺ oxidation reduces device performance and stability. To address this problem, we propose a new approach, i.e. fabrication of mesoporous n-i-p Sn-based PSCs with the photoactive composite made of mixed-organic-cation Sn halide perovskite and reduced graphene oxide (rGO) sheets anchored with Sn quantum dots (i.e., FA_0.8MA_0.2SnI₃/rGO-Sn QDs). The rGO-Sn QDs in active layer not only suppress the destructive Sn²⁺/Sn⁴⁺oxidation and recombination but also accelerate charge transport, improve charge-carrier lifetime and reduce trap state density. Compared to the power conversion efficiency (PCE) of Sn-PSC without Sn QDs, the composite-basted champion device showed 55% increase in efficiency, attributed to strong suppression of Sn²⁺/Sn⁴⁺oxidation and recombination. Furthermore, the champion device showed remarkable reproducibility and stability improvement, representing an essential step for the practical use of low-cost and lead-free PSCs.

锡 (Sn) 卤化物钙钛矿一直是无铅钙钛矿太阳能电池 (PSC) 的有希望的候选材料，但由于 Sn ²⁺ /Sn ⁴⁺氧化导致其化学不稳定性降低了器件性能和稳定性。为了解决这个问题，我们提出了一种新方法，即使用由混合有机阳离子卤化锡钙钛矿和还原氧化石墨烯 (rGO) 片制成的光敏复合材料制造介孔 nip Sn 基 PSCs（即， FA _0.8 MA _0.2 SnI ₃ /rGO-Sn QD）。有源层中的 rGO-Sn QDs 不仅抑制了破坏性的 Sn ²⁺ /Sn ⁴⁺氧化和复合，但也加速电荷传输，提高电荷载流子寿命并降低陷阱态密度。与没有 Sn QD 的 Sn-PSC 的功率转换效率 (PCE) 相比，基于复合材料的冠军器件的效率提高了 55%，这归因于对 Sn ²⁺ /Sn ⁴⁺氧化和复合的强烈抑制。此外，冠军器件表现出显着的重现性和稳定性改进，代表了低成本和无铅 PSC 的实际应用的重要一步。