Disorder Engineering for Continuous Excited‐State Tuning in Hybrid Glass Scintillators

Conventional scintillators rely on crystalline lattices that lock luminescent centers into discrete, fixed configurations, fundamentally restricting the dynamic regulation of emission pathways. Here, we establish a strategy for tuning excited‐state behavior in hybrid glass scintillators by harnessing structural disorder as an active design parameter for regulating local Mn coupling environments. Through non‐stoichiometric engineering of hybrid organic–inorganic (methyl(triphenyl)phosphonium) 2 MnBr 4 (MTP 2 MnBr 4 ) glasses, continuously distributed Mn–Mn coupling environments are established within a single amorphous phase, spanning from isolated Mn monomers to exchange‐coupled pairs. This disorder‐mediated coupling landscape reconstructs the excited‐state hierarchy and facilitates excited‐state energy redistribution, producing continuously tunable luminescence from green to orange‐red under both UV and X‐ray excitation. The optimized glass achieves a light yield of 43 825 photons MeV −1 and spatial resolution of 13.6 lp mm −1 , rivaling commercial standards. Leveraging the composition‐dependent emission contrast, flexible glass‐core fibers are fabricated for quantitative ratiometric X‐ray dosimetry, with potential for wearable radiation monitoring. This work establishes disorder engineering as a general strategy for reconstructing local excited‐state configurations beyond the constraints of crystalline symmetry.