In this report, we present a new approach for the fabrication and application of Cs₄PbBr₆ microcrystals (Cs₄PbBr₆ MCs). The Cs₄PbBr₆ MCs are synthesized via an anti-solvent induced crystallization of PbBr₂:CsBr directly in dimethylsulfoxide (DMSO) by introducing HBr (HBr, 48% aqueous solution). The ratio of HBr and DMSO plays a vital role in the formation of Cs₄PbBr₆. By controlling the HBr/DMSO ratio, pure Cs₄PbBr₆ or the CsPbBr₃ phase can be obtained. The Cs₄PbBr₆ MCs were initially obtained by adding HBr to CsBr:PbBr₂/DMSO. However, on increasing the amount of the added HBr, Cs₄PbBr₆ MCs were converted to CsPbBr₃ MCs and the photoluminescence (PL) disappeared. It was also found that CsPbBr₃ MCs can be transformed to Cs₄PbBr₆ MCs by simply adding DMSO to the dried CsPbBr₃ MCs. The Cs₄PbBr₆ MCs exhibit a strong PL at 516 nm with a full width at half-maximum of 25 nm regardless of the crystal size (5–10 μm). On using Cs₄PbBr₆ MCs as a light converter in ultraviolet light emitting diodes, a PL intensity that is 3 times higher than that of CsPbBr₃ quantum dots based devices could be achieved, unraveling the potential of this material for optoelectronic applications.

中文翻译：

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低温固溶处理的溴化铯铅微晶用于光转换

在本报告中，我们介绍了一种用于Cs ₄ PbBr ₆微晶（Cs ₄ PbBr ₆ MC）的制造和应用的新方法。通过直接在二甲亚砜（DMSO）中通过引入HBr（HBr，48％水溶液）的PbBr ₂：CsBr的反溶剂诱导结晶来合成Cs ₄ PbBr ₆ MC 。HBr和DMSO的比例在Cs ₄ PbBr ₆的形成中起着至关重要的作用。通过控制HBr / DMSO比，可以获得纯的Cs ₄ PbBr ₆或CsPbBr ₃相。Cs ₄ PbBr ₆首先通过将HBr添加到CsBr：PbBr ₂ / DMSO中获得MC 。但是，随着HBr的添加量增加，Cs ₄ PbBr ₆ MCs转变为CsPbBr ₃ MCs，光致发光（PL）消失了。还发现通过简单地将DMSO添加到干燥的CsPbBr ₃ MC中，可以将CsPbBr ₃ MC转化为Cs ₄ PbBr ₆ MC。Cs ₄ PbBr ₆ MC在516 nm处显示出很强的PL，最大宽度为25 nm的一半，而与晶体大小（5-10μm）无关。使用Cs ₄ PbBr _6时作为紫外发光二极管中的光转换器，MC可以实现PL强度是基于CsPbBr ₃量子点的器件的PL强度的3倍，从而揭示了这种材料在光电应用中的潜力。