High Pressure Restrains the Photo‐Induced Polyhedra Distortion in 0D Antimony‐Based Metal Halide

Abstract Recently, dual emission phenomena based on excitation‐dependent emission are increasingly observed in 0D antimony‐based metal halides. However, the origins of these two emissions remain debated. Herein, high pressure is employed to investigate the structural‐optical relationship of the typical 0D antimony‐based metal halides (TTA) 2 SbCl 5 (TTA = tetraethylammonium) and uncover mechanisms behind its emission. As pressure increases, the dual emission of (TTA) 2 SbCl 5 under 303 nm excitation, characterized by high energy and low energy emission peaks, transitions to a single low energy emission peak at ≈5.7 GPa. Meanwhile, a single broadband emission peak excited by 355 nm maintains a distinct low energy emission peak throughout the compression process, exhibiting an excitation‐dependent emission color response. Combining experiment results with density functional theory calculations, the observed phenomenon is attributed to pressure restrain of photo‐induced distortion in the [SbCl 5 ] 2 ⁻ polyhedra in (TTA) 2 SbCl 5 . These finding reveals the relationship between the local structure and excitation‐dependent emission, providing new perspectives and insights into the modulation of Sb‐based metal halides.