Discovery of Mechanoluminescence in an Antimony‐Based Organic–Inorganic Hybrid Metal Halide

Abstract Metal halides have garnered significant attention owing to their tunable emission characteristics and exceptional optoelectronic properties. Despite thorough investigation into their electroluminescence (EL) and photoluminescence (PL) properties, the mechanoluminescence (ML) behavior of these materials, which is pivotal for applications like stress‐sensitive sensors and anti‐counterfeiting, is overlooked. This issue is tackled by reporting the discovery of efficient ML in antimony‐based hybrid metal halides, MTP 2 SbCl 5 , utilizing a unique molecular design that integrates inorganic luminescent centers within an organic conjugated cationic matrix. This structure promotes spatial isolation of luminescent sites, reducing non‐radiative decay and enhancing emission efficiency to 100%. Furthermore, in this structure, the disruption of strong intermolecular forces induces charge rearrangement and the establishment of an electrostatic field, which constitutes the primary mechanism underlying the formation of ML. To demonstrate practicality, MTP 2 SbCl 5 /PDMS elastomers are engineered, which showcase exceptional performance in dynamic pressure mapping and information encryption. This research not only broadens the utility of metal halides but also paves the way for a versatile approach to crafting ML materials for advanced optoelectronics.