Chiral Blue-Light Excited Hybrid Copper Iodides with Circularly Polarized Luminescence for Lighting and X-ray Imaging

Abstract

Abstract Chiral hybrid Cu(I) halides combine outstanding optoelectronic properties with structural chirality, making them promising materials for diverse applications. However, the use of chiral hybrid copper(I) halides for lighting and X-ray scintillators remains largely unexplored. Herein, a pair of chiral hybrid Cu(I) iodides (1-R and 1-S) were prepared, with their chirality unequivocally confirmed by second-harmonic generation (SHG) measurements. Both compounds exhibit yellow broadband emission peaking at 545 nm under blue-light excitation, with a photoluminescence quantum yield (PLQY) of 96%. Theoretical and photophysical studies uncover that their emission arises from two distinct self-trapped exciton (STE) states. Both compounds show pronounced circularly polarized luminescence (CPL), possessing luminescence dissymmetry factors (glum) on the order of 10–3. Based on compound 1-R, a single-component white light-emitting diode (WLED) with a color rendering index (CRI) of 81 was developed. Meanwhile, compound 1-R demonstrates strong X-ray absorption, a high light yield of 24,528 photons·MeV–1, and a low detection limit of 112 nGy·s–1, enabling the corresponding flexible film to achieve an X-ray imaging spatial resolution of about 7 lp·mm–1. This study establishes a reliable strategy for discovering stable and highly efficient chiral hybrid metal halides with multifunctional properties.