Pixel‐Registered Trimodal Visible/NIR/X‐Ray Imaging Enabled by a Single‐Material Rare‐Earth‐Free Double Perovskite

ABSTRACT Multimodal imaging that integrates x‐ray, white light, and near‐infrared (NIR) information offers enhanced diagnostic accuracy. However, the absence of material that can efficiently respond to all three types of signals requires the use of separate hardware for each modality, inevitably causing pixel misalignment and complicating system integration. To address this, we develop a Te 4+ /Mo 4+ co‐doped Cs 2 HfCl 6 perovskite microcrystals (MCs) platform. Rational dopant engineering yields an optimized composition (3%Te 4+ , 5%Mo 4+ ) that simultaneously emits in the visible (570 nm, PLQY = 17.6%, from Te 4+ self‐trapped excitons) and NIR (910 nm, PLQY = 41.7%, from Mo 4+ d‐d transitions) regions. The high‐Z host also ensures strong x‐ray absorption, leading to exceptional x‐ray scintillation performance with a light yield of 35 073 photons/MeV, a detection limit of 81.43 nGy air /s, and a spatial resolution of 13.6 lp/mm. The resulting flexible PDMS composite films function concurrently as white‐light and NIR‐emitting diodes, as well as high‐resolution x‐ray screens. Using a single detector with switchable excitation (450 nm LED or x‐rays), we demonstrated pixel‐registered trimodal imaging of a screw‐ink‐capsule phantom without the need for post‐processing alignment. This rare‐earth‐free, all‐in‐one material strategy provides a compact and scalable route toward next‐generation multimodal medical diagnostics.