Sensitive direct-conversion X-ray detectors formed by ZnO nanowire field emitters andβ-Ga_(2)O_(3)photoconductor targets with an electron bombardment induced photoconductivity mechanism

Sensitive X-ray detection is needed in diverse areas motivated by a common desire to reduce radiation dose.Cold cathode X-ray detectors operating with a photoelectron multiplication mechanism called electron bombardment induced photoconductivity(EBIPC)have emerged as promising candidates for low-dose X-ray detection.Herein,the cold cathode detectors formed by ZnO nanowire field emitters andβ-Ga_(2)O_(3)photoconductor targets were proposed for sensitive direct-conversion X-ray detection.The charge carrier transport mechanism of EBIPC effect in X-ray detectors was investigated to achieve a high internal gain(2.9×10^(2))and high detection sensitivity(3.0×10^(3)μCGy^(−1)_(air)cm^(−2))for a 6 keV X-ray at the electric field of 22.5 Vμm−1.Furthermore,the proposed X-ray detectors showed the features of fast response time(40 ms),long-term stability(0.6%for 1 h),and low detection limit(0.28 mGy_(air)s^(−1)),suggesting that the direct-conversion cold cathode X-ray detectors are ideal candidates for low-energy X-ray detecting and imaging applications.