Paradigm Enhancement of White‐Light Responsive NIR‐II Photoluminescence via Toroidal Energy Migration

Abstract Near‐infrared II (NIR‐II, 1000–1700 nm) lanthanide‐doped fluorescent probes provide a powerful new tool for existing clinical biomedical sensing and imaging. However, it is impeded in practical applications by its specific high‐energy laser source. Herein, a white‐light responsive Ce 3+ ‐mediated toroidal energy migration downshifting topological core–shell structure NIR‐IIb (1500–1700 nm) fluorescent probe is reported. It is found that Ce 3+ doping enhances the NIR downshifting luminescence of the Ho 3+ and Nd 3+ , thereby increasing the energy‐transferred Yb 3+ luminescence. The NaCeF 4 core is able to further facilitate the crossrelaxation between the intermediate‐shell layer of Er 3+ and Ce 3+ through the outward‐to‐inward core–shell topology, enhancing the 1527 nm luminescence to form the toroidal energy migration paradigm. Additionally, the luminescence of Er 3 ⁺ exhibits strong temperature dependence, enabling superior temperature sensing under multiple light sources. Under low‐power white light source, the relative sensitivity ( S r ) can reach up to 0.57% K −1 , with a minimum temperature uncertainty ( δT ) of 0.2 K. Moreover, portable light conversion using highly efficient white‐light responsive emission in NIR‐II region enables noninjectable intravenous imaging and food inspection. This toroidal energy migration strategy provides a new direction for lanthanide energy harvesting and multisource NIR applications.