A Zero-Dimensional Hybrid Cadmium Perovskite with Highly Efficient Orange–Red Light Emission

Low-dimensional organic-inorganic hybrid metal halide materials have been extensively studied due to their excellent optoelectronic performances. Herein, by using the facile wet-chemistry method, we designed one new hybrid cadmium bromide of (H₃AEP)₂CdBr₆·2Br based on discrete octahedral [CdBr₆]^4- units. Remarkably, the bulk crystal of (H₃AEP)₂CdBr₆·2Br exhibits strong broadband orange-red light emission from the radiative recombination of self-trapped excitons (STEs) with a high photoluminescence quantum yield (PLQY) of 9%. Benefiting from the highly efficient luminescent performance, this 0D cadmium perovskite can be utilized as an excellent down-conversion red phosphor to assemble a white light-emitting diode, and a high color rendering index (CRI) of 93 is realized. As far as we know, this is the first orange-red light-emitting hybrid cadmium perovskite which promotes the full-color display in this system.