To evaluate the charge transport behaviors associated with the temperature variation,the pulse height spectra of CdZnTe crystals were obtained under various bias voltages,in the temperature range of 230-300K, using an un-collimated 241 Am a particles source with the energy of 5.48MeV. It was demonstrated that the photopeak positions were non-sensitive to the temperature for high quality CdZnTe crystals. In terms of CdZnTe crystal with de-trapping level defects, the charge drift velocity was significantly delayed due to the re-emission of charge carriers out of the traps. The pulse shapes shown distinct exponential decay component which enhanced as decreasing the temperature. 241 Am@59.5keV y-ray spectroscopy response of CZT detector were compared at room temperature and 280K. In addition, the leakage current of the detector, under the electrical field strength of 1500V/cm,were evaluated as a function of the temperature.%采用未经准直能童为5.48MeV的241 Am α粒子,研究了温度在230-300K范围内,不同电场作用下CdZnTe晶体的脉冲响应信号,分析了载流子传输特性随温度变化的规律.对比了室温(298K)以及280K下探测器对241 Am@59.5keVγ射线的响应光谱.同时分析了1500V/cm电场作用下探测器漏电流随温.度的变化规律.研究表明,对于性能优异的CdZnTe晶体,载流子迁移率寿命积随温度变化较小.而对于存在de-trapping(去俘获)缺陷的CdZnTe样品,光生载流子在晶体中的传输会显著减缓,且随温度的降低,其对脉冲波形的影响加剧.而温度降低可以减少提高探测器的能量分辫率.
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