Bright emitting lead halide perovskite nanocrystals reported to date are mostly obtained in a six-faceted perfect cube shape. While extensive research has been carried out for intensifying and stabilizing the bright emission of these nanocrystals, little attention has been paid to obtaining isotropic (sphere-like) nanocrystals in other shapes. Using a nanocrystal-to-nanocrystal dissolution–formation protocol and under limited ligands and insufficient halides in reaction medium, herein, dimension-variable faceted isotropic orthorhombic phase CsPbBr₃ nanocrystals beyond the cubic shape are reported, and their optical properties are studied. The size and facets of these nanocrystals were also tuned as a function of injection temperature. However, unlike cube-shaped samples, because these nanocrystals were prepared under ligand- and halide-deficient conditions, they showed poor emission efficiency. Because these were colloidally stable, beyond light-emitting devices, these might be useful as a potential material in other applications where suppression of charge carrier recombination is essential.

中文翻译：

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各向同性的CsPbBr ₃钙钛矿纳米晶体超越了纳米立方体：生长和光学性质

迄今报道的发亮的卤化钙钛矿型纳米铅晶体大多以六面完美立方体形状获得。虽然已经进行了广泛的研究以增强和稳定这些纳米晶体的明亮发射，但是很少关注获得其他形状的各向同性（球形）纳米晶体。使用纳米晶体到纳米晶体的溶解形成方案，并在有限的配体和反应介质中卤化物不足的情况下，本文采用尺寸可变的多面各向同性正交晶相CsPbBr ₃报告了立方形状以外的纳米晶体，并研究了它们的光学性质。这些纳米晶体的大小和刻面也根据注入温度进行了调整。但是，与立方体状样品不同，由于这些纳米晶体是在配体和卤化物不足的条件下制备的，因此它们的发射效率很低。因为它们是胶体稳定的，所以除了发光器件之外，它们还可以用作潜在应用，在抑制电荷载流子复合至关重要的其他应用中。