Photoluminescence Enhancement of 0D Organic–Inorganic Metal Halides via Aggregation‐Induced Emission and Halide Substitution

Abstract 0D organic–inorganic metal halides (OIMHs) provide unprecedented versatility in structures and photoluminescence properties. Here, a series of bluish‐white emissive 0D OIMHs, (TPE‐TPP) 2 Sb 2 Br x Cl 8‐x (x = 1.16 to 8), are prepared by assembling the 1‐triphenylphosphonium‐4‐(1,2,2‐triphenylethenyl)benzene cation (TPE‐TPP) + with antimony halides anions. Based on experimental characterizations and theoretical calculations, the emission of the 0D OIMHs are attributed to the fluorescence of the organic cations with aggregation‐induced emission (AIE) properties. The 0D structure minimized the molecular motion and intermolecular interactions between (TPE‐TPP) + cations, effectively suppressing the non‐radiative recombination processes. Consequently, the photoluminescence quantum efficiency (PLQE) of (TPE‐TPP) 2 Sb 2 Br 1.16 Cl 6.84 is significantly enhanced to 55.4% as compared to the organic salt (TPE‐TPP)Br (20.5%). The PLQE of (TPE‐TPP) 2 Sb 2 Br x Cl 8‐x can also be readily manipulated by halide substitution, due to the competitive processes between non‐radiative recombination on the inorganic moiety and the energy transfer from inorganic to organic. In addition, electrically driven light‐emitting diodes (LEDs) are fabricated based on (TPE‐TPP) 2 Sb 2 Br 1.16 Cl 6.84 emitter, which exhibited bluish‐white emission with a maximum external quantum efficiency (EQE) of 1.1% and luminance of 335 cd m −2 . This is the first report of electrically driven LED based on 0D OIMH with bluish‐white emission.