Broadband electroluminescence based on environment-friendly emitters is promising for healthy lighting yet remains an unprecedented challenge to progress. The copper halide-based emitters are competitive candidates for broadband emission, but their high-performance electroluminescence shows inadequate broad emission bandwidth of less than 90 nm. Here, we demonstrate efficient ultra-broadband electroluminescence from a copper halide (CuI) nanocluster single emitter prepared by a one-step solution synthesis-deposition process, through dedicated design of ligands and subtle selection of solvents. The CuI nanocluster exhibits high rigidity in the excitation state as well as dual-emissive modes of phosphorescence and temperature-activated delayed fluorescence, enabling the uniform cluster-composed film to show excellent stability and high photoluminescent efficiency. In consequence, ultra-broadband light-emitting diodes (LEDs) present nearly identical performance in an inert or air atmosphere without encapsulation and outstanding high-temperature operation performance, reaching an emission full width at half maximum (FWHM) of ~120 nm, a peak external quantum efficiency of 13%, a record maximum luminance of ~50,000 cd m⁻², and an operating half-lifetime of 137 h at 100 cd m⁻². The results highlight the potential of copper halide nanoclusters for next-generation healthy lighting.

基于环保发射器的宽带电致发光有望实现健康照明，但仍然是一个前所未有的进步挑战。卤化铜基发射器是宽带发射的竞争候选者，但其高性能电致发光显示出不足的小于 90 nm 的宽发射带宽。在这里，我们通过专门的配体设计和精细的溶剂选择，展示了通过一步溶液合成-沉积工艺制备的卤化铜（CuI）纳米团簇单发射体的高效超宽带电致发光。 CuI纳米团簇在激发态下表现出高刚性以及磷光和温度激活延迟荧光的双发射模式，使得均匀的团簇组成的薄膜表现出优异的稳定性和高光致发光效率。因此，超宽带发光二极管（LED）在惰性或空气气氛中表现出几乎相同的性能，无需封装，并且具有出色的高温工作性能，达到~120 nm的发射半峰全宽（FWHM），峰值外量子效率为 13%，创纪录的最大亮度约为 50,000 cd m ^{-2 ，并且在 100 cd m -2}下的工作半衰期为 137 小时。研究结果凸显了卤化铜纳米团簇在下一代健康照明方面的潜力。