Ternary copper halides are promising materials for lighting and displays, but red emission has yet to be reported among this class of materials due to the difficulty in tuning the self-trapped exciton (STE) emission. Here, we report lead-free hybrid organic–inorganic ternary copper halides A₆(DMSO)₁₂[Cu₈Br₁₃][Cu₄Br₄(OH)(H₂O)] (ACB-DMSO, A = K, Rb) synthesized as single crystals and microcrystalline suspensions. These materials emit in the red portion of the visible spectrum with a high photoluminescence quantum yield (PLQY) of up to 75%. The changes in the emission spectrum are caused by the solvent-induced transformation from the STE emitter A₂CuBr₃ to phosphorescent ACB-DMSO which reversibly transforms blue-emitting 1D copper chains to red-emitting 0D copper clusters. K₆(DMSO)₁₂[Cu₈Br₁₃][Cu₄Br₄(OH)(H₂O)] (A = K) can be used as the red-emitting phosphor for red light-emitting didoes (LEDs), and by adding blue and green emitting cesium copper halides, an all copper-based white LED with a high color rendering index (CRI) over 97% is achieved.

中文翻译：

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调整自陷发射：向 0D 铜簇的可逆转变允许溴化钾和铷铜中的亮红色发射

三元卤化铜是用于照明和显示器的有前途的材料，但由于难以调节自陷激子 (STE) 发射，因此此类材料中尚未报道红光发射。在这里，我们报告了无铅杂化有机-无机三元卤化铜 A ₆ (DMSO) ₁₂ [Cu ₈ Br ₁₃ ][Cu ₄ Br ₄ (OH)(H ₂ O)] (ACB-DMSO, A = K, Rb ) 合成为单晶和微晶悬浮液。这些材料在可见光谱的红色部分发射，具有高达 75% 的高光致发光量子产率 (PLQY)。发射光谱的变化是由 STE 发射体 A 的溶剂诱导转变引起的₂ CuBr ₃到磷光 ACB-DMSO，可将发蓝光的 1D 铜链可逆地转变为发红光的 0D 铜簇。K ₆ (DMSO) ₁₂ [Cu ₈ Br ₁₃ ][Cu ₄ Br ₄ (OH)(H ₂ O)] (A = K) 可用作红色发光二极管 (LED) 的红色荧光粉，通过添加蓝色和绿色发光铯铜卤化物，实现了具有超过 97% 的高显色指数 (CRI) 的全铜基白光 LED。