Large-scale preparation of Sb 3+ -activated hybrid metal halides with efficient tunable emission from visible to near-infrared regions for advanced photonic applications

Zero-dimensional metal halides with diverse structures and rich photophysical properties have been reported. However, achieving multimode dynamic luminescence and efficient near-infrared (NIR) emission under blue light excitation in a single system is a great challenge. Herein, Sb³⁺-doped hybrid Cd(II) halides were synthesized by a large scale synthesis process at room temperature. Compared with the poor emission of (C₁₂H₂₈N)₂CdX₄ (C₁₂H₂₈N = tetrapropylammonium; X = Cl and Br) and single steady-state visible light emission of (C₁₂H₂₈N)₂SbX₅, (C₁₂H₂₈N)₂CdX₄:Sb³⁺ exhibits efficient tunable emission from visible to NIR regions. More specifically, (C₁₂H₂₈N)₂CdCl₄:Sb³⁺ exhibits distinct excitation wavelength-dependent luminescence characteristics, which can change from green to white and orange emission. Parallelly, halogen substitution can regulate the optical properties of Sb³⁺-doped (C₁₂H₂₈N)₂CdCl_4-xBr_x (x = 0-1), which enables the excitation and emission bands to exhibit a significant redshift. Thus, the efficient broad NIR emission upon 450 nm excitation was realized in (C₁₂H₂₈N)₂CdBr₄:Sb³⁺. In addition, we demonstrated the use of (C₁₂H₂₈N)₂CdCl₄:Sb³⁺ phosphors in solid state lighting, and an advanced NIR light source was fabricated by coating (C₁₂H₂₈N)₂CdBr₄:Sb³⁺ on a commercial blue chip (450 nm), which exhibits the most advanced photoelectric efficiency (14.67%) and output power (32.84 mW) in hybrid metal halides. Finally, we also demonstrated the use of Sb³⁺-activated phosphors in four-level fluorescence anti-counterfeiting and information encryption.