Quasi-1D Energy Transfer Enabling TbWO:Eu Scintillator for Low-Dose High-Resolution X-Ray Imaging.

A primary challenge in inorganic scintillators development is maximizing the X-ray energy conversion efficiency. Conventional low-doping strategies in rare-earth systems mitigate concentration quenching but result in inefficient host-to-activator energy transfer, leading to significant energy losses. To overcome this, a novel rare-earth matrix design is proposed: using Tb ions as the host lattice and incorporating energy-matched Eu ions as activators. This design enabled highly efficient energy transfer from the host to the luminescent centers. Experiments confirmed that quasi-1D Tb chains (intra-chain distance: 3.92 Å, inter-chain distance: 5.92 Å) enabled Dexter-type energy transfer (Tb: D → Eu: D/D), achieving near-unity energy transfer efficiency. The optimized TbWO:0.2Eu@PMMA film exhibited an X-ray light yield of 25 000 photons·MeV at 22 keV, a spatial resolution of 14 lp mm, and an ultra-low detection limit (14.1 nGy s). High-resolution radiography of biological specimens validated imaging capability at the 0.1 mm scale. This work established a paradigm for designing high-sensitivity scintillators through quasi-1D energy transfer, advancing low-dose X-ray imaging applications in medical diagnostics and industrial inspection.