Highly efficient and blue-light-excitable zero-dimensional hybrid copper iodides toward solid-state lighting and x-ray imaging applications

Organic–inorganic hybrid metal halides have gained significant attention as downconversion phosphors in solid-state lighting and x-ray imaging due to their unique optical properties. However, achieving efficient luminescence under blue light excitation remains a significant challenge. Herein, we present a novel zero-dimensional hybrid copper iodide Li(H2O)(Benzo-15-crown-5)22Cu4I6 (abbreviated as LB2Cu4I6), as a highly efficient and blue-light-excitable emitter with potential in lighting and x-ray imaging applications. This compound exhibits an ultrabroad excitation band spanning from 250 to 500 nm, upon blue light, ultraviolet, or x-ray excitation, delivers strong broadband yellow emission centered at 541 nm with a high photoluminescence quantum yield (PLQY) of 92.1%. Benefiting from their strong photoexcitation under blue light, high PLQY, and good environmental stability, a high-performance white light-emitting diode was developed, achieving a commercial-level luminous efficiency of 101.6 lm W−1, a high color rendering index of 87, and a record half-lifetime of 2352 h. Additionally, LB2Cu4I6 demonstrates outstanding x-ray scintillation properties with a high light yield of 83 904 photons MeV−1, a low detection limit of 72.3 nGy s−1, and a competitive spatial resolution of 10.3 lp mm−1 for x-ray imaging. This work provides a new avenue for exploring highly efficient and blue-light-excitable luminescent metal halides toward multifunctional applications.