Improved Carrier Transport and Enhanced Detection Sensitivity Through Zr ⁴⁺ Doping in LiYMo ₂ O ₈ Single Crystals for X-ray Detectors

X-ray detectors play an important role in medical imaging, security inspection, industrial nondestructive testing, and high-energy physics. Oxide single crystals are attractive candidates for direct X-ray detection because of their high chemical stability, good mechanical robustness, and feasibility for large-size crystal growth. However, their ultrahigh intrinsic resistivity often limits photocurrent generation and thus restricts detection sensitivity. Here, Zr doping is proposed as a strategy to regulate carrier transport in LiYMo 2 O 8 (LYMO) single crystals. Pristine LYMO and Zr-doped LYMO crystals were successfully grown by the top-seeded solution growth method. The pristine LYMO crystal exhibits resistivities of 9.96 × 10 13 and 1.44 × 10 14 Ω cm along the a - and c -axes, respectively, with corresponding mobility-lifetime ( μτ ) products of 1.15 × 10 –3 and 1.81 × 10 –3 cm 2 V –1 . After Zr incorporation, the a -axis resistivity decreases to 5.68 × 10 9 Ω cm, while the μτ product increases to 8.97 × 10 –3 cm 2 V –1 . As a result, the a -axis X-ray sensitivity reaches 431 μC Gy –1 cm –2 under 40 keV X-ray irradiation, more than twice that of the pristine LYMO detector. The Zr-doped LYMO detector also maintains low detection limits of 50.1 and 29.8 nGy s –1 along the a - and c -axes, respectively. These results demonstrate that rational Zr 4+ donor doping is an effective approach to balancing resistivity, charge collection efficiency, and baseline stability in high-resistivity oxide crystals for improved X-ray detection.