Cesium copper halides (CCHs) show promise for optoelectronic applications, and their syntheses usually involve high-temperatures and hazard solvents. Herein, the synthesis of highly luminescent and phase-pure Cs₃Cu₂X₅ (X = Cl, Br, and I) and CsCu₂I₃ via a solvent-free mechanochemical approach through manual grinding is demonstrated. This cost-effective approach can produce CCHs on a scale of tens to hundreds of grams. Rietveld refinement analysis of the X-ray diffraction patterns of the as-synthesized CCHs reveals their structural details. Notably, the emission characteristics of green-emitting, chloride-based CCHs remain stable even at elevated temperatures—maintaining 80% of initial PL efficiency at 150 °C. Lastly, a postsynthetic reversible transformation between zero- and one-dimensional CCH materials is demonstrated, indicating the labile nature of their crystal structure. The proposed study suggests that mechanochemistry can be an alternative and promising synthetic tool for fabricating high-quality lead-free metal halides.

中文翻译：

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机械化学作为绿色路线：高发光铯铜卤化物的合成，热稳定性和合成后可逆相变。

卤化铯铜（CCHs）具有光电子应用前景，其合成通常涉及高温和有害溶剂。此处，合成了高发光且纯相的Cs ₃ Cu ₂ X ₅（X = Cl，Br和I）和CsCu ₂ I ₃通过无溶剂机械化学方法，通过手动研磨进行了演示。这种经济高效的方法可以生产数十至数百克的六氯环己烷。合成的CCH的X射线衍射图的Rietveld精细分析揭示了它们的结构细节。值得注意的是，即使在升高的温度下，发绿光的氯化物基CCH的发射特性仍保持稳定-在150°C时保持初始PL效率的80％。最后，证明了零维和一维CCH材料之间的合成后可逆转变，表明其晶体结构的不稳定性质。拟议的研究表明，机械化学可以成为制造高质量无铅金属卤化物的另一种有希望的合成工具。