Copper(I) halides have recently attracted increasing attention in a variety of photonics applications, owing to their highly luminescent efficiency, nontoxicity, and low-dimensional electronic structure. Moreover, combining compositional engineering and mass production of new materials may further enrich the research and application of functional materials. Herein, we controllably synthesized two series of novel mixed-halide Cs₃Cu₂Cl_5-xI_x and Cs₅Cu₃Cl_8-xI_x powders via the compositional engineering for the first time. The crystal structures are identified with Rietveld refinement and density functional theory calculations. The mixed-halide compound exhibits relatively wide full width of half-maximum (~70 nm), adjustable bandgap (from 449 nm to 486 nm), larger Stokes shifts (~200 nm), and dramatic improved stability with high efficiency (photoluminescence quantum yield at least 90.61%), which present a scalable strategy for mass production for practical applications. In addition, the controllable phase transformation from blue-emitting Cs₃Cu₂I₅ to yellow-emitting CsCu₂I₃ was confirmed. Most notably, the white light is obtained by combining novel Cs₃Cu₂Cl_5-xI_x/Cs₅Cu₃Cl_8-xI_x with yellow-emitting CsCu₂I₃ powders. Based on this, we firstly introduce the blue-emitting Cs₅Cu₃Cl₇I powders in white LED fabrication by combining ultraviolet chip and as-prepared yellow-emitting CsCu₂I₃ powders, to generate high-quality and stability white light with CIE coordinates of (0.335, 0.398) and colour rendering index value of 77.8. For comparison, red-emitting CaAlSiN₃:Eu²⁺ phosphors are also introduced for LED package to substitute CsCu₂I₃ powders, which exhibit the high colour rendering index of 89.2. This work not only develops new mixed-halide compounds with high stability and performance, but also provides the unique strategy for promoting industrialization process of LED backlights.

卤化铜（I）由于其高发光效率，无毒和低维电子结构，最近在各种光子学应用中引起了越来越多的关注。此外，将成分工程与新材料的批量生产相结合可以进一步丰富功能材料的研究和应用。在这里，我们可控制地合成了两个系列的新型混合卤化物Cs ₃ Cu ₂ Cl _5-x I _x和Cs ₅ Cu ₃ Cl _8-x I _x粉末首次通过成分工程。晶体结构通过Rietveld精炼和密度泛函理论计算确定。混合卤化物化合物具有相对宽的半峰全宽（〜70 nm），可调节带隙（从449 nm 至486 nm），更大的斯托克斯位移（〜200 nm）和显着提高的稳定性以及高效率（光致发光量子）收率至少为90.61％），为实际应用提供了可扩展的批量生产策略。另外，证实了从发蓝光的Cs ₃ Cu ₂ I ₅到发黄光的CsCu ₂ I ₃的可控相变。最值得注意的是，白光是通过结合新型Cs获得的₃ Cu ₂ Cl _5-x I _x / Cs ₅ Cu ₃ Cl _8-x I _x具有发 黄光的CsCu ₂ I ₃粉末。在此基础上，我们首先将紫外芯片与已制备的发黄光的CsCu ₂ I ₃粉末相结合，在白光LED制造中引入发蓝光的Cs ₅ Cu ₃ Cl ₇ I粉末，以产生高质量，稳定的白光。 CIE坐标为（0.335，0.398），显色指数值为77.8。为了进行比较，发红光的CaAlSiN ₃：Eu ²⁺  还引入了用于LED封装的荧光粉来 替代 CsCu ₂ I ₃ 粉末，该粉末具有89.2的高显色指数。这项工作不仅开发出具有高稳定性和性能的新型混合卤化物，而且为促进LED背光的工业化进程提供了独特的策略。