Efficient Tunable White Emission and Blue Light‐Excited Near‐Infrared Emission in Lead‐Free Metal Halide Crystals with Ultra‐High Luminous Efficiency for Multispectral Image Fusion and 3D Image Reconstruction

Abstract 0D hybrid Sb(III) halides generally exhibit unique crystal structure and efficient emission. However, achieving efficient white light and blue light‐excited near‐infrared (NIR) emission remains an enormous challenge. Herein, a series of 0D hybrid Sb(III) halides of (18‐crown‐6@K)₂SbX₅ (X = Cl, Br) crystals with different Cl/Br rations are synthesized via supramolecular self‐assembly. All compounds show the broadband emission, which stems from the self‐trapped excitons in [SbX₅]²⁻ pseudo‐octahedral structure. Particularly, (18‐crown‐6@K)₂SbCl₅ crystal shows tunable emission under various excitation wavelengths, and the efficient white emission with an ultra‐high luminous efficiency of 92.3% is obtained under 310 nm excitation. As Br gradually replaces Cl, not only the excitation and emission bands show a red‐shift but also facilitate the intersystem crossing process from singlet to triplet excitons. Thus, an independent broadband NIR emission upon 450 nm excitation with an ultra‐high luminous efficiency of 58.2% is obtained in (18‐crown‐6@K)₂SbBr₅ crystals. Moreover, the high‐performance single‐component white light‐emitting diode (WLED) based on (18‐crown‐6@K)₂SbCl₅ and NIR LED based on (18‐crown‐6@K)₂SbBr₅ are fabricated, and white light and NIR image fusion is realized. Finally, combined with multiangle imaging under WLED and NIR LED irradiation, the 3D image reconstruction of a centrifuge tube wrapped in a capsule is successfully demonstrated.