Acid‐Programmed Generation of Coordination, Ionic, and All‐In‐One Cu(I) Chloride Architectures with Highly Efficient Luminescence

Copper(I)-based hybrid halides feature highly designable structures, systematic tunability, and excellent photoluminescence; however, developing design rules that can predictably modulate their emission across different structural types remains under explored. Here, we report an acid-programmed generating approach, in which reaction acidity simultaneously modulates ligand protonation and the nucleation barrier, thereby generating coordination, ionic, and all-in-one copper(I) chloride architectures by tuning reaction acidity and affording six new compounds with emissions spanning 520-625 nm. Among these, the AIO compound 3 A-1H[CuCl₂] (A = 4-(aminomethyl)pyridine, 4AMP) exhibits a record-high photoluminescence quantum yield (PLQY) of 99%, setting a new benchmark for AIO Cu(I)-based emitters. Temperature-dependent photoluminescence and time-resolved spectroscopy reveal that the ultrahigh PLQY originates from enhanced lattice rigidity and a triplet phosphorescence pathway. Solubility and thin film fabrication demonstrate excellent processability, while long-term stability stands in stark contrast to the notorious instability of conventional Cu(I) halides. Moreover, mixing compounds yields broad-range white-light emission, underscoring the potential of materials for tunable and high-efficiency solid-state lighting. This study establishes acid-driven structural integration as a general strategy for constructing functional copper(I) halide compounds, laying the foundation for stable, solution-processable, and high-performance optoelectronic materials.