Achieving Luminous Efficiency Enhancement and Near‐Infrared Emission in Moisture‐Stable 0D Zinc‐Based Halides

Abstract Zero‐dimensional (0D) metal halides are attractive due to their structure‐dependent and tunable photoluminescence properties. Herein, a new 0D organic–inorganic hybrid Zn‐based halide, (C 4 H 12 N 2 )ZnBr 4 , featuring a long‐term stable crystal structure and moisture‐stable PL emission under various extreme conditions is reported. A strong electron–phonon coupling effect enables the Zn‐based halide to display highly efficient blue light at 472 nm with a large Stokes shift of 7385 cm −1 . Intriguingly, heterovalent substitution of Cu + ‐Zn 2+ further enhances the photoluminescence quantum efficiency to 60% as the introduction of Cu + effectively suppresses the nonradiative recombination process. Besides, the formation of twisted [SbBr 4 ] − tetrahedra via Sb 3+ ‐Zn 2+ substitution help to achieve a broadband near‐infrared (NIR) emission (760 nm) with full width at half maxima (FWHM) of 203 nm, enabling the potential applications in night‐vision and nondestructive fruit damage inspection. Detailed structural and optical analyses are used to investigate the photophysical processes of different self‐trapped exciton (STE) emission for pristine and Cu + /Sb 3+ ‐doped 0D metal halides. These findings advance the understanding of spectral regulation mechanism via heterovalent substitution and initiate more exploitation of luminescent metal halides for emerging applications.