The temporal response of cadmium-zinc-telluride(CZT) crystals is evaluated at room temperature by using an ultrafast-pulsed x-ray source. The dynamics of carrier relaxation in a CZT single crystal is modeled at a micr...The temporal response of cadmium-zinc-telluride(CZT) crystals is evaluated at room temperature by using an ultrafast-pulsed x-ray source. The dynamics of carrier relaxation in a CZT single crystal is modeled at a microscopic level based on a multi-trapping effect. The effects of the irradiation flux and bias voltage on the amplitude and full width at half maximum(FWHM) of the transient currents are investigated. It is demonstrated that the temporal response process is affected by defect level occupation fraction. A fast photon current can be achieved under intense pulsed x-ray irradiation to be up to 2.78×10~9 photons mm-2·s-1. Meanwhile, it is found that high bias voltage could enhance carrier detrapping by suppressing the capture of structure defects and thus improve the temporal response of CZT detectors.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51702271 and U1631116)the Young and Middle-aged Teachers Education and Scientific Research Foundation of Fujian Province,China(Grant No.JAT170407)+1 种基金the High Level Talent Project of Xiamen University of Technology,China(Grant No.YKJ16016R)the Fund of the State Key Laboratory of Solidification Processing in NWPU,China(Grant No.SKLSP201741)
文摘The temporal response of cadmium-zinc-telluride(CZT) crystals is evaluated at room temperature by using an ultrafast-pulsed x-ray source. The dynamics of carrier relaxation in a CZT single crystal is modeled at a microscopic level based on a multi-trapping effect. The effects of the irradiation flux and bias voltage on the amplitude and full width at half maximum(FWHM) of the transient currents are investigated. It is demonstrated that the temporal response process is affected by defect level occupation fraction. A fast photon current can be achieved under intense pulsed x-ray irradiation to be up to 2.78×10~9 photons mm-2·s-1. Meanwhile, it is found that high bias voltage could enhance carrier detrapping by suppressing the capture of structure defects and thus improve the temporal response of CZT detectors.
