Effect of temperature on the carrier transportation and spectral properties of CdZnTe

Planar detectors were fabricated from single crystal CdZnTe (CZT) grown using the vertical Bridgman method. We tested the leakage current and resistance of the detector under various voltage in the temperature ranges of 210-300 K. Using an un-collimated ²⁴¹Am α particles source with the energy of 5.48 MeV, the mobility of electron was determined to be 1360 cm ²/V ^-1s ^-1 and the electron-life changing with temperature was estimated. To evaluate the carrier transport behaviors associated with the temperature variation, the pulse spectra of CZT crystals to ²⁴¹Am@59.5 keV γ-ray were obtained under various bias voltages, in the temperature range of 220-300 K. It is demonstrated that the concentration of the charge carriers is reduced with decreasing the temperature, results in increasing bulk resistivity, and therefore improved the energy resolution is improved. But when the temperature decreased below 253 K, the energy resolution deteriorateds.