Thermally Activated Delayed Fluorescence Delivers High-Efficiency Blue Persistent Luminescence in Metallic Halide Perovskites
Tianhong Chen, Chao Wang, Jiawen Xiao, Dongpeng Yan
Abstract
Metallic halide perovskites have aroused widespread interest for applications in light-emitting diodes, photodetectors, and lasers.However, highly efficient blue-light emitting systems with extremely high quantum yields and ultralong exciton lifetimes are rare, despite their importance for long persistent luminescence (PersL) in sustainable lighting sources, information encryption, biomedicine, and X-ray imaging.In this work, we introduce a wet-chemical synthesis procedure to achieve PersL in all-inorganic perovskite with thermally activated delayed fluorescence (TADF) for high quantum yields (97.7%).The Cs 2 ZrCl 6 :1.9%Ag2.27%Inmicrocrystals emits blue PersL lasting over 10,000 s, along with strong X-ray absorption and light yield of up to 40,782.8photons/ MeV, outperforming state-of-the-art commercial counterparts.Furthermore, a fabricated flexible scintillator screen demonstrates high X-ray spatial resolution (15.6 lp mm -1 ) and an impressive detection limit (46.5 nGy s -1 ), 118 times lower than typical medical imaging doses.Through a combination of both experiments and theoretical calculations, this work not only proposes a TADF-mediated PersL for efficient blue light-emitting with near-unity photoluminescence quantum yield and hours-scale PersL in all-inorganic perovskites, but also enables advancing applications in sensitive X-ray detection, information security, and storage.