High-Efficiency Intrinsic Yellow-Orange Emission in Hybrid Indium Bromide with Double Octahedral Configuration

Zero-dimensional (0D) In-based organic–inorganic metal halides (OIMHs) have received growing interest in recent years as promising luminescent materials. However, the high efficiencies of 0D In-based OIMHs are all dependent on Sb doping in the existing literature. Here, we report a novel 0D In-based OIMH (C 10 H 22 N 2 ) 2 In 2 Br 10, which exhibits intrinsic broadband emission (610 nm), and the photoluminescence quantum yield (PLQY) can reach 70% without Sb doping. (C 10 H 22 N 2 ) 2 In 2 Br 10 shows a typical 0D structure with three different In–Br polyhedra (two octahedra and one tetrahedron) separated by large organic cations. Based on the optical property measurements and theoretical calculations, we demonstrate that (C 10 H 22 N 2 ) 2 In 2 Br 10 is an indirect semiconductor with a band gap of 3.74 eV, and the In–Br inorganic moiety is primarily responsible for the intense emission of (C 10 H 22 N 2 ) 2 In 2 Br 10 . Interestingly, the unique double octahedral configuration in (C 10 H 22 N 2 ) 2 In 2 Br 10 may enhance the structural distortion and stimulate the self-trapped excitons (STEs), leading to the related high PLQY. Our work provides a novel 0D In-based OIMH with high-efficiency intrinsic emission, which is helpful for understanding the structure–PL relationships of hybrid halides.