Achieving Centimeter‐Sized Mn‐Based Hybrid Metal Halides with Anisotropic Emission, Scintillation, and Anti‐Thermal‐Quenching Photoluminescence for Linearly Polarized UV Light, X‐Ray, and Temperature Sensing

Multi‐field sensing luminescent crystals responsive to linearly polarized UV light, X‐rays, and temperature show great value in high‐precision thermometry and non‐destructive testing. Herein, we report a centimeter‐sized zero‐dimensional Mn‐based hybrid metal halide (C 11 H 8 F 2 N) 2 MnCl 4 via an organic‐inorganic coupling strategy, integrating anisotropic photoluminescence, scintillation, and anti‐thermal‐quenching properties. The anisotropic arrangement of organic cations enables polarization‐dependent Mn 2+ emission with a polarization degree of 0.36, realizing quantitative detection of the electric field vector for the first time in hybrid metal halides. The 0D configuration also suppresses non‐radiative transitions, resulting in a high photoluminescence quantum yield of 94.6% and a scintillation light yield of 27,000 photons/MeV under X‐ray excitation, with a low detection limit of 2.19 µGy/s and a high spatial resolution of 11.1 LP/mm. Furthermore, the adaptive fine‐tuning of organic cation spatial configuration with increasing temperature modulates their light absorption, leading to a pronounced anti‐thermal‐quenching behavior of Mn 2+ luminescence with a 1.73‐fold enhancement over 20–260 K. Using 1% Sb 3+ doping, a ratiometric temperature sensor is achieved with a maximum absolute sensitivity of 0.392 K −1 at 300 K and relative sensitivity of 3.88%·K −1 at 20 K, displaying excellent overall performance. This work provides a new strategy for designing multi‐field sensing hybrid metal halides.