“Pyramid‐Top” Fluorination in Antimony Halides for Wide‐Response‐Range and High‐Sensitivity Fluorescence Lifetime Thermometry

ABSTRACT High‐precision non‐invasive thermometry is transforming the landscape of modern microelectronics. However, achieving superior sensitivity across a broad high‐temperature range using low‐dimensional metal halides remains a formidable challenge. Herein, a unique “pyramid‐top” fluorination strategy is proposed to significantly improve the thermometric properties of zero‐dimensional (0D) hybrid antimony halides. By directionally substituting the apical bromine in the [SbBr 5 ] 2− pyramid with highly electronegative fluorine, the density of basal‐plane bromine vacancies acting as intrinsic shallow‐level defects is precisely modulated. This lattice engineering can not only rigidify the “soft” framework of the 0D halides but also promote efficient thermally activated radiative recombination through artificial trap states, thereby markedly suppressing the notorious thermal quenching. As a result, the fluorinated (CTPP) 2 SbFBr 4 crystal achieves an operational range of 272–384 K and a record sensitivity of 0.042 K −1 at 440 K, surpassing its fluorine‐free analogues. More importantly, these fluorinated antimony halides also exhibit exceptional resistance to polar solvents, as well as superior thermal stability. These properties enable the solution‐processed (CTPP) 2 SbFBr 4 thin film to function as a high‐fidelity thermal‐sensing layer, facilitating accurate, high‐resolution lifetime thermography for industrial temperature monitoring. Unambiguously, this work will establish a rational design strategy for lead‐free halide thermographic materials with tunable optoelectronic properties.