Effect of space charge-limited mechanism on the x-ray detection performance of Ni/Au <i>β</i>-Ga2O3 Schottky diode at high temperature

Gallium oxide-based (Ga2O3) detectors have shown great potential for x-ray detection. In specific high-temperature environmental application scenarios such as plasma radiation monitoring, Ga2O3 detectors are required to maintain high sensitivity and low noise-equivalent dose (NED) rate. The x-ray detection performance of Ga2O3 detectors at high temperature has not been well studied, making the applications of Ga2O3 detectors for such conditions challenging. In this paper, a vertical Ni/Au β-Ga2O3 Schottky barrier diode was prepared, and its x-ray detection performance at high temperature was analyzed. The specific sensitivity (Rs) of the detector at 500 K with −200 V bias was 1.75 × 10−3 C/(Gy cm2), and the NED was 8.11 × 10−9 Gy/(s Hz0.5). Compared to the 300 K test result, Rs went up by a factor of 14.11, while the NED remained at the same level. Additionally, the response of the detector became faster with increasing temperature. The detector exhibited higher sensitivity and faster response time at high temperatures, which is attributed to the space-charge-limited current and photoconductive mechanisms induced by the deep energy levels within β-Ga2O3. In addition, a model of the carrier transport process is established. The results imply the great potential of the Ni/Au β-Ga2O3 SBD for high-temperature x-ray detection applications.