Artificial solids of CsPbX₃ perovskite nanocrystals (NC) are well known for their promising charge transport characteristics. The long-range diffusion of photoinduced charges in these materials is attributed to the unique electronic structure of CsPbX₃ NCs associated with high defect tolerance and a low disorder of excited-state energies. Here, we show that the same set of electronic properties allows CsPbBr₃ NC solids to act as superior energy transport materials, which support a long-range diffusion of electrically neutral excitons. By performing time-resolved bulk quenching measurements on halide-treated CsPbBr₃ NC films, we observed average exciton diffusion lengths of 52 and 71 nm for I^–- and Cl^–-treated solids, respectively. Steady-state fluorescence quenching studies have been employed to explain such a large diffusion length as due to a high defect tolerance and a low disorder of exciton energies in CsPbBr₃ NC solids. We expect that the demonstrated ability of halide-treated CsPbBr₃ NC solids to support a long-range exciton transport could be beneficial for applications in light energy concentration, as was demonstrated in this work through energy transfer measurements in assemblies of perovskite NC donors and CdSe quantum dot acceptors.

中文翻译：

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CsPbBr ₃钙钛矿纳米晶体固体中的能量传输

CsPbX ₃钙钛矿纳米晶体（NC）的人工固体以其有希望的电荷传输特性而闻名。这些材料中光诱导电荷的长距离扩散归因于CsPbX ₃ NC的独特电子结构，该结构与高缺陷耐受性和低激发态能量无序有关。在这里，我们证明了相同的电子性质允许CsPbBr ₃ NC固体充当优良的能量传输材料，从而支持电中性激子的远距离扩散。通过在卤化处理CsPbBr进行时间分辨的块状淬火测量₃ NC膜，我们观察到的52和71处的平均激子扩散长度的I ^- -和Cl^–处理过的固体。由于CsPbBr ₃ NC固体中的高缺陷耐受性和低激子能量紊乱，稳态荧光猝灭研究已被用来解释如此长的扩散长度。我们希望，通过钙钛矿型NC供体和CdSe组装体中的能量转移测量可以证明，卤化物处理过的CsPbBr ₃ NC固体具有支持远距离激子传输的能力，可能有益于光能集中的应用。量子点受体。