Enhancing the Anti‐Thermal Quenching Photoluminescence of Yb ³⁺ in Double Perovskites via Thermally‐Accelerated Energy Transfer

Abstract Metal halide perovskites doped with rare‐earth ions have promising application prospects in cutting‐edge optoelectronic fields due to their excellent photoluminescence quantum efficiency. However, the weak near‐infrared (NIR) emission and poor thermal quenching performance severely limit their further applications. Herein, a versatile strategy is reported for enhancing the anti‐thermal quenching of rare‐earth NIR photoluminescence by energy transfer. The orthogonal experiment has confirmed that doping with Sb 3+ ions not only facilitates absorption and energy transfer (ET) but also establishes an effective thermal‐accelerated ET channel through Sb 3+ ions, thereby enhancing the anti‐thermal quenching performance of Yb 3+ NIR emission. As the temperature increases, the ET efficiency gradually increases from 5.6% at 100 K to a maximum of 89% at 250 K, which further confirms the thermal‐acceleration ET process. This unique temperature response facilitates dual‐mode optical thermometry based on visible and NIR emission, with a relative sensitivity of 7.4% K −1 at 300 K. Furthermore, the as‐synthesized samples demonstrate promising applications in non‐contact optical thermometers and non‐destructive examination. Overall, this work has opened a new perspective for developing rare‐earth‐doped NIR luminescent materials with enhanced anti‐thermal quenching performance, and simultaneously, clarifying their underlying mechanism by the unique thermally‐accelerated ET process.