Colloidal lead‐free perovskite nanocrystals have recently received extensive attention because of their facile synthesis, the outstanding size‐tunable optoelectronic properties, and less or no toxicity in their commercial applications. Tin (Sn) has so far led to the most efficient lead‐free solar cells, yet showing highly unstable characteristics in ambient conditions. Here, we propose the synthesis of all‐inorganic mixture Sn‐Ge perovskite nanocrystals, demonstrating the role of Ge²⁺ in stabilizing Sn²⁺ cation while enhancing the optical and photophysical properties. The partial replacement of Sn atoms by Ge atoms in the nanostructures effectively fills the high density of Sn vacancies, reducing the surface traps and leading to a longer excitonic lifetime and increased photoluminescence quantum yield. The resultant Sn‐Ge nanocrystals‐based devices show the highest efficiency of 4.9 %, enhanced by nearly 60 % compared to that of pure Sn nanocrystals‐based devices.

中文翻译：

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B位点与锗的共合金化提高了全无机锡基钙钛矿纳米晶体太阳能电池的效率和稳定性。

胶体无铅钙钛矿纳米晶体最近受到广泛关注，因为它们易于合成，具有出色的尺寸可调光电性能，并且在商业应用中毒性较小或无毒性。迄今为止，锡（Sn）已成为最高效的无铅太阳能电池，但在环境条件下表现出高度不稳定的特性。在这里，我们提出合成全无机混合物Sn-Ge钙钛矿纳米晶体，证明Ge ²⁺在稳定Sn ²⁺阳离子同时增强光学和光物理性质方面的作用。纳米结构中Ge原子部分取代Sn原子有效地填充了高密度的Sn空位，减少了表面陷阱，从而延长了激子寿命并提高了光致发光量子产率。所得的 Sn-Ge 纳米晶器件的最高效率为 4.9%，与纯 Sn-Ge 纳米晶器件相比提高了近 60%。