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.