Reversible Dual‐Mode X‐Ray Memory Imaging of Photochromic Zero‐Dimensional Halide Perovskite Glass

ABSTRACT Integrating photochromic and photoluminescence (PL) properties of halide perovskite glasses enables reversible luminescence modulation and expands their practical functionality. However, realizing photochromic halide perovskite glasses remains a significant challenge. Here, we report the fabrication of Cs 4 PbBr 6 ‐containing perovskite quantum dot inorganic glasses using a melt‐quenching and subsequent thermal treatment process, which exhibit a reversible color transition between yellow and brown under alternating X‐ray irradiation and 532 nm laser bleaching. We demonstrate that the X‐ray–induced photochromism originates from the formation of color centers through electron trapping at oxygen vacancies in the borophosphate glass network, while the reversible PL modulation is governed by the synergistic effects of reabsorption and excitonic behavior. Moreover, we reveal that both the coloration contrast and PL intensity exhibit mono‐exponential dependencies on X‐ray irradiation dose, enabling dual‐mode X‐ray dosimetry and memory imaging. This work establishes a new strategy for integrating radiation sensitivity and reversible optical properties within a single halide perovskite glass, providing valuable insights for the design of multifunctional luminescent materials.