Quasi-1D Energy Transfer Enabling Tb₂W₃O₁₂:Eu³⁺ 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 Tb³⁺ ions as the host lattice and incorporating energy-matched Eu³⁺ ions as activators. This design enabled highly efficient energy transfer from the host to the luminescent centers. Experiments confirmed that quasi-1D Tb³⁺ chains (intra-chain distance: 3.92 Å, inter-chain distance: 5.92 Å) enabled Dexter-type energy transfer (Tb³⁺: ⁵D₄ → Eu³⁺: ⁵D₁/⁵D₂), achieving near-unity energy transfer efficiency. The optimized Tb_1.8W₃O₁₂:0.2Eu³⁺@PMMA film exhibited an X-ray light yield of 25 000 photons·MeV^-1 at 22 keV, a spatial resolution of 14 lp mm^-1, and an ultra-low detection limit (14.1 nGy_air s^-1). 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.