Less-toxic tin-based perovskite materials have received more attention because they are a potential alternative to toxic Pb-based perovskite materials. However, the device performance of Sn-based perovskite solar cells is still far behind that of their Pb-based counterparts. In addition to easy oxidation of Sn²⁺ and fast crystallization, energy level mismatch is the other important factor inhibiting the improvement of device performance. In the study, we synthesized a new material, 5-mercapto-1-methyltetrazole tin salt, SnT₂, as a regulator of the energy level of Sn-based perovskites. The results show that deeper valence bands and conduction bands were detected after SnT₂ addition, which can give a better energy level alignment. Furthermore, the introduction of SnT₂ also achieved the reduction of trap densities and enlargement of the grain size of perovskite films. Consequently, a 15.33% device performance was realized with an open-circuit voltage of 842.6 mV, short-circuit current density of 24.72 mA cm^–2, and fill factor of 0.736.

中文翻译：

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在锡基钙钛矿太阳能电池中通过能量水平调节实现超过 15% 的性能


毒性较小的锡基钙钛矿材料受到了更多关注，因为它们是有毒的 Pb 基钙钛矿材料的潜在替代品。然而，Sn 基钙钛矿太阳能电池的器件性能仍远落后于其 Pb 基太阳能电池。除了 Sn²⁺ 易氧化和快速结晶外，能级失配是抑制器件性能改善的另一个重要因素。在这项研究中，我们合成了一种新材料，5-巯基-1-甲基四唑锡盐 SnT₂，作为 Sn 基钙钛矿能级的调节剂。结果表明，添加 SnT₂ 后检测到更深的价带和导带，可以提供更好的能级对齐。此外，SnT₂ 的引入还实现了陷阱密度的降低和钙钛矿薄膜晶粒尺寸的扩大。因此，在开路电压为 842.6 mV、短路电流密度为 24.72 mA cm^–2 和填充因数为 0.736 的情况下，器件性能达到 15.33%。