Organic–inorganic hybrid perovskite solar cells have demonstrated unprecedented high power conversion efficiencies in the past few years. Now, the universal instability of the perovskites has become the main barrier for this kind of solar cells to realize commercialization. This situation can be even worse for those tin-based perovskites, especially for CsSnI₃, because upon exposure to ambient atmosphere the desired black orthorhombic phase CsSnI₃ would promptly lose single crystallinity and degrade to the inactive yellow phase, followed by irreversible oxidation into metallic Cs₂SnI₆. By alloying CsSnI₃ with CsPbI₃, we herein report the synthesis of alloyed perovskite quantum dot (QD), CsSn_1–xPb_xI₃, which not only can be phase-stable for months in purified colloidal solution but also remains intact even directly exposed to ambient air, far superior to both of its parent CsSnI₃ and CsPbI₃ QDs. Ultrafast transient absorption spectroscopy studies reveal that the photoexcited electrons in the alloyed QDs can be injected into TiO₂ nanocrystals at a fast rate of 1.12 × 10¹¹ s^–1, which enables a high photocurrent generation in solar cells.

中文翻译：

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气态稳定的合金CsSn _{1– x} Pb _x I ₃钙钛矿纳米晶体的胶体合成，用于太阳能电池

在过去的几年中，有机-无机杂化钙钛矿太阳能电池表现出空前的高功率转换效率。现在，钙钛矿的普遍不稳定性已经成为这类太阳能电池实现商业化的主要障碍。对于那些锡基钙钛矿，尤其是对于CsSnI _3来说，这种情况甚至会更糟，因为在暴露于大气中后，所需的黑色正交相CsSnI ₃会迅速失去单晶性并降解为惰性黄色相，随后不可逆地氧化为金属。 Cs ₂ SnI ₆。通过将CsSnI ₃与CsPbI ₃合金化，我们在此报告了合金化钙钛矿量子点（QD）CsSn _{1- x} Pb _x I ₃的合成，它不仅可以在纯化的胶体溶液中稳定数月，而且即使直接暴露于环境空气中也可以保持完整无损。优于其父级CsSnI ₃和CsPbI ₃ QD。超快速瞬态吸收光谱研究表明，合金量子点中的光激发电子可以1.12×10 ¹¹ s ^–1的快速速率注入TiO ₂纳米晶体中，从而可以在太阳能电池中产生高光电流。