Efficient and Anti-Thermal Quenching Luminescence of Ce3+ Sensitized Rare-Earth-Based Double Perovskite Cs2NaHoCl6 Single Crystals for Versatile Photoelectric Applications

Lead-free halide double perovskites (DPs) have attracted growing attention owing to their eco-friendly composition and remarkable optoelectronic performance. However, it remains a challenge to develop DPs that simultaneously achieve high photoluminescence quantum yield (PLQY), excellent stability, and multifunctional applications. Herein, rare-earth-based DPs Cs 2 NaHoCl 6 single crystals are successfully synthesized, which achieve the optimized red and near-infrared (NIR) emissions of Ho 3+ through doping Ce 3+ ions. Benefiting from strong absorption of Ce 3+ and efficient energy transfer to Ho 3+ under 340 nm excitation, the PLQY remarkably increases from 3.67% to 92.56%, which are confirmed by experimental analyses and density functional theory calculations. Meanwhile, taking advantage of abnormal anti-thermal quenching luminescence of Ho 3+ and highly efficient thermal response capability of Stark levels of 5 F 5 within the temperature range of 80–500 K, the prepared DPs provide a distinctive platform for luminescence thermometer with a superior relative sensitivity value of 5.19% K −1 at 80 K and red-NIR light-emitting diode. These results not only establish Ce 3+ as a generalizable strategy for optimizing luminescence in rare-earth-based DPs, but also open new avenues for their multiple potential applications in solid-state lighting, temperature sensing, night vision imaging as well as plant growth illuminating.