Enhanced Blue Emission <i>via</i> Pressure Treatment of an Organic‐Inorganic Zinc Bromide^†

Comprehensive Summary Pressure‐treatment has been shown to be an effective means to enhance fluorescence of organic‐inorganic halides though it is only limited to few examples. Here, we report the pressure‐dependent structural evolution and emission enhancement upon compression treatment of a zero‐dimensional halide, BTPP 2 ZnBr 4 (BTPP = Benzyl triphenyl phosphonium). Compared to the uncompressed BTPP 2 ZnBr 4 crystal, the pressure‐treated sample shows a maximum 7‐fold intensified fluorescence at ambient conditions while maintaining the wide‐spectrum blue emission feature. This significantly boosted emission is attributed to the pressure‐induced irreversible structural distortion which effectively reduces the non‐radiative recombination. This work demonstrates the promising potential of pressure treatment in achieving bright organic‐inorganic halide emitters and other molecular fluorescent materials.