Near-unity Photoluminescence Quantum Yield in Zero-Dimensional Lead-Free Indium-Based Hybrid Perovskites by Antimony Doping

High-performance broadband emission with a near-unity photoluminescence quantum yield of ∼99.3% was observed in (C 4 H 12 N) 2 InC 5 ·DMF:Sb 3+ hybrid perovskites, which can be attributed to the self-trapped excitons of the [SbCl 5 ·DMF] 2− polyhedron.