Tailorable Photonic Blocks within Well‐Defined Framework for Architecting MOFs Scintillators

Scintillators have attracted widespread attention due to their remarkable ability to convert high‐energy X‐ray photons into ultraviolet/visible light. However, inherent limitations such as compositional rigidity and unpredictable reaction dynamics hinder the precise structural engineering and optimization of luminescent performance. Metal–organic frameworks (MOFs) provide a promising platform to address these challenges due to their highly tunable structure and customizable modularity. Herein, a modular engineering strategy is proposed and develop a programmable assembly platform based on a series of Ln‐MOFs with identical topology structures. Through rational energy level engineering, the obtained Ln‐MOFs scintillators exhibit intense X‐ray excited luminescence, high relative light yield, perfect linear response to X‐ray dose rate, and excellent stability. The fabricated MOF‐based scintillating membranes demonstrate promising potential in flexible X‐ray imaging with high spatial resolution. Some fundamental design principles are elucidated through investigating systematic correlation of scintillating performance with energy levels, luminescent efficiency, and self‐absorption effects. This modular engineering strategy yields a structural model for developing advanced inorganic‐organic hybrid scintillators with tailored optoelectronic properties.