Exciton Modulation in MOF-Templated Quasi-Two-Dimensional Perovskites for High-Resolution and Rapid Dynamic X-ray Imaging

The widespread application of dynamic X-ray imaging in fields such as medical angiography necessitates increasingly stringent requirements for scintillating materials. Quasi-two-dimensional (quasi-2D) halide perovskites, owing to their intrinsic quantum well structure and pronounced exciton effects, have garnered significant interest for high-sensitivity, fast-response radiation detectors. However, the fundamental structure–property relationship governing the correlation between layered dimensionality and radiative response remains unclear. Herein, we present a novel strategy involving in situ, spatially confined synthesis of quasi-2D Ruddlesden–Popper (RP) perovskites with tailored quantum well thicknesses ( n -values) inside metal–organic frameworks (MOFs) matrix. In this quasi-2D perovskites/MOFs structure, MOF nanopores serve as preferential nucleation sites, effectively mitigating perovskite phase segregation and minimizing interfacial defect densities, while the MOF framework facilitates passivation of surface dangling bonds, which synergistically enhances the radiative recombination rate by complementing the layered effect. Additionally, by directionally modulating the exciton binding energy via n -value gradient, an optimal exciton binding energy of 106.43 meV was achieved with n = 4, enabling a detection limit below 92 nGy/s and high-resolution, rapid dynamic imaging. This composite also exhibits excellent optical stability, confirming the protective effect of the MOF matrix on the perovskite device. This work provides a promising MOF-perovskite heterojunction approach for radiation sensing under harsh environments.