High‐Quality Ceramic Polycrystalline Wafers Fabricated by High‐Temperature Sintering for Sensitive and Ultrastable X‐Ray Detection

Abstract The development of large, millimeter‐thick X‐ray‐sensitive wafers is crucial for advancing the application of large‐area X‐ray imaging detectors in medical and structural diagnostics. Polycrystalline wafers (PWs) offer adjustable size, controllable thickness, and environmental stability, making them advantageous for X‐ray detection. Among the various materials, high‐temperature‐sintered metal oxide ceramic PWs demonstrate particular promise owing to their robustness in harsh conditions. However, their X‐ray detection performance requires further improvement. This work introduces CeO 2 ceramic PWs as an innovative material for X‐ray detection. The dense CeO 2 wafers prepared by high‐temperature sintering exhibit high crystal quality with a high resistivity (8.3 × 10 10 Ω cm), low dark current drift (1.1 × 10 −7 nA cm −1 s −1 V −1 ), and high mobility‐lifetime product (8.48 × 10 −4 cm 2 V −1 ). As a result, the fabricated detectors achieve state‐of‐the‐art performance metrics among previously reported lead‐free X‐ray detectors, exhibiting a sensitivity of 1799.6 µC Gy −1 cm −2 , a detection limit of 24.4 nGy s −1 , and a spatial resolution of 5.4 lp mm −1 . Moreover, the detectors exhibit ultrastability, encompassing superior operational stability, irradiation stability, moisture stability, and thermal stability. Overall, CeO 2 ceramic PWs represent a significant advancement in X‐ray detection technology, providing both high performance and practical durability for next‐generation imaging applications.