Research on Spatial Ionizing Radiation Effects on VOx Uncooled Infrared Focal Plane Arrays

[Background]: Vanadium oxide (VOx) detector plays a crucial role in the fields of space infrared detection and imaging due to their sensitivity to infrared radiation, particularly in the Long-Wave Infrared (LWIR) band, coupled with their advantages of high sensitivity, low noise, uncooled operation, and cost-effectiveness. However, performance degradation caused by space ionizing radiation, particularly the decrease in responsivity and the increase in noise levels, poses a significant threat to the imaging quality and reliability of these detectors. [Purpose]: To bridge the current gap in research on the space radiation effects on VOx detectors and provide input for their radiation hardening, [Methods]: This study aims to present ground-based radiation simulation experiments and analyze the radiation damage to detectors. Both online and offline testing methods were employed to systematically investigate the changes in detector output under varying radiation doses. Furthermore, post-irradiation annealing tests were conducted on the detectors to deeply explore the specific patterns of performance degradation in VOx detectors under space radiation environments. [Results]: The results indicate that space radiation significantly affects the output performance of VOx detectors. When the accumulated dose reaches 31 krad(Si), the non-uniformity of the detector's blackbody temperature response and the number of dead pixels surge. At 39 krad(Si), the non-uniformity of the blackbody response escalates to 88%, the dead pixel rate climbs to 66%, and the output image becomes aberrant. Within 24 hours after the irradiation test, the annealing effect of the VOx infrared array detector is evident, with the average grayscale value of the blackbody response output closely aligning with the pre-irradiation results after 72 hours of annealing, and the number of dead pixels tending towards zero after one week of annealing. [Conclusions]: Space radiation significantly impacts the output of VOx detectors, with the detector's output performance declining as the radiation dose accumulates, reaching a point where the device cannot recognize objects in images at 24 krad(Si). The total ionizing dose effect at lower accumulated dose values does not constitute permanent damage, as the detector's performance can be restored through room-temperature annealing. This study provides valuable insights for the subsequent design of radiation-hardened VOx detectors for space applications.

[背景]：氧化钒（Vanadium oxide, VOx）探测器因其对红外辐射，尤其是长波红外（Long-Wave Infrared, LWIR）波段的辐射具有高灵敏度，同时兼具高灵敏度、低噪声、非制冷工作以及成本效益优异等优势，在空间红外探测与成像领域发挥着至关重要的作用。然而，空间电离辐射引发的性能退化问题——尤其是响应度下降与噪声水平上升——正对这类探测器的成像质量与可靠性构成严重威胁。
[目的]：为弥补当前氧化钒探测器空间辐射效应研究的空白，并为其辐射加固提供重要参考依据，
[方法]：本研究旨在开展地面辐射模拟实验并分析探测器的辐射损伤情况。研究采用在线与离线测试相结合的方法，系统探究不同辐射剂量下探测器输出的变化规律。此外，还对探测器开展了辐后退火测试，以深入解析空间辐射环境中氧化钒探测器性能退化的具体特征。
[结果]：研究结果表明，空间辐射会显著影响氧化钒探测器的输出性能。当累积剂量达到31 krad(Si)时，探测器黑体温度响应的非均匀性与死像素数量均大幅激增。当累积剂量达39 krad(Si)时，黑体响应非均匀性升至88%，死像素率攀升至66%，输出图像出现畸变。在辐照测试后的24小时内，氧化钒红外阵列探测器的退火效果已较为显著；退火72小时后，黑体响应输出的平均灰度值与辐照前结果基本一致；退火一周后，死像素数量趋近于零。
[结论]：空间辐射会显著影响氧化钒探测器的输出性能，其输出表现随辐射剂量累积逐渐劣化，当累积剂量达24 krad(Si)时，探测器已无法识别图像中的目标。低累积剂量下的总电离剂量效应不会造成永久性损伤，探测器性能可通过室温退火得以恢复。本研究可为后续面向空间应用的抗辐射加固氧化钒探测器设计提供极具价值的参考依据。