Record‐High Resolution X‐Ray Imaging With Multi‐Component and Near‐Infrared Organic Scintillators Enabled by TADF Sensitization

Organic X-ray scintillators face significant challenges in achieving high-resolution imaging, primarily due to the inherent difficulty in synergizing high X-ray attenuation ability, efficient exciton utilization, and low self-absorption. Herein, we report a series of organic scintillators, which set new resolution records for molecular-sensitized organic scintillators. By pairing a high-efficiency thermally activated delayed fluorescence (TADF) sensitizer with three different types of emitters [TADF, triplet-triplet annihilation (TTA), and fluorescent], we demonstrate excellent control over scintillator properties. The resulting systems show outstanding performance, with the TTA-based system achieving a spatial resolution of 35.9 lp/mm, the highest reported to date for multi-component organic scintillators. Notably, the fluorescent system reaches 21.6 lp/mm in the near-infrared (NIR) region, representing a 41% improvement over the previous state-of-the-art. This work provides an effective and systematic design strategy for creating the next generation of high-resolution organic scintillators, demonstrating record-high system-level performance suitable for advanced imaging applications.