Highly Emissive Organic Cuprous Halides with [Cu4Br6]2- Unit for X-Ray Imaging

Organic-inorganic hybrid cuprous halides (OHCHs) are intriguing candidates for the next generation of scintillators due to their environmental friendliness, simple preparation, and excellent luminescent properties. Herein, a series of efficient OHCHs based on inorganic building blocks [Cu4Br6](2-) clusters, designated as (TMAA)(2)Cu4Br6, (EtTPPh)(2)Cu4Br6, and (MtTBA)(2)Cu4Br6 (TMAA = N,N,N-trimethyltrimethyl-1-adamantylammonium; EtTPPh = ethyltriphenylphosphonium; MtTBA = methyltri-n-butylammonium), are synthesized via a simple solution method. The three OHCHs exhibit broadband yellow emissions. Remarkably, the 0D (TMAA)(2)Cu4Br6 shows a near-unity photoluminescence quantum yield, which can be attributed to the highly localized excitons and rigid environment. Impressively, it is demonstrated to show excellent scintillation performance with a high light yield of 46700 photon MeV-1 and a low detection limit of 56.12 nGy(air)s(-1). Photophysical studies reveal that the bright emission in (TMAA)(2)Cu4Br6 originates from self-trapped excitons. This work opens an inspirational avenue in structure design for OHCHs as high-performance X-ray scintillators.