Highly Stable Orange‐Red Long‐Persistent Luminescent CsCdCl3:Mn2+ Perovskite Crystal

Abstract Halide perovskite has been widely studied as a new generation of photoelectronic materials. However, their thermal and humidity‐induced emission quenching have greatly limited their utility and reliability. Here, we report a hexagonal Mn 2+ ‐doped CsCdCl 3 perovskite crystal that possesses stable photoluminescence (PL) at both high temperature and humidity. The room temperature long‐persistent luminescence (LPL) of the single crystals lasts up to 1480 s and can be adjusted by changing the concentration of Mn 2+ ion doping. The characteristic emission of d‐d transition of Mn 2+ is realized, and the photoluminescence quantum yield (PLQY) is up to 91.4 %, it can maintain more than 90 % of the initial PL spectral integral area at 150 °C (423 K). High humid stability PL can be achieved more than 75 % of the initial PL intensity after 55 days of immersion in water. These excellent properties show the application prospect of the LPL material in lighting indication and anti‐counterfeiting.