Tin (Sn) halide perovskites are promising materials for various electronic applications due to their favorable properties. However, facile interaction with atmospheric oxygen (O₂) often hinders the practical use of Sn-based perovskites, which is regarded as a major cause of undesired variations in their electrical and structural properties. Herein, we report the reversible p-doping in phenethylammonium tin iodide ((PEA)₂SnI₄) transistors when they are exposed sequentially to ambient and vacuum conditions. Exposure to ambient conditions induces p-doping effects that lead to a significant shift in the threshold voltage. Interestingly, we have found that the unintentionally p-doped (PEA)₂SnI₄ transistors can be fully restored by simply exposing them to vacuum, indicating a complete dedoping without any structural or operational degradation. Our first-principles calculations further support the observations by revealing that the doping by O₂ molecules occurs via occupying the interstitial sites that form acceptor levels close to the valence band maximum of (PEA)₂SnI₄.

中文翻译：

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二维卤化锡钙钛矿场效应晶体管中的可逆氧化 p 掺杂

卤化锡（Sn）钙钛矿由于其良好的性能而成为各种电子应用中很有前景的材料。然而，与大气氧（O ₂ ）的容易相互作用常常阻碍锡基钙钛矿的实际使用，这被认为是其电学和结构性能发生不良变化的主要原因。在此，我们报道了苯乙铵锡碘化物（(PEA) ₂ SnI ₄）晶体管在依次暴露于环境和真空条件下时的可逆 p 掺杂。暴露在环境条件下会引起 p 掺杂效应，从而导致阈值电压发生显着变化。有趣的是，我们发现无意的 p 掺杂 (PEA) ₂ SnI ₄晶体管只需将其暴露在真空中即可完全恢复，这表明完全去掺杂而没有任何结构或操作退化。我们的第一原理计算进一步支持了我们的观察结果，揭示了 O ₂分子的掺杂是通过占据形成接近 (PEA) ₂ SnI ₄价带最大值的受主能级的间隙位点而发生的。