采用改进的垂直布里奇曼生长法生长CdZnTe(CZT)单晶, 并在晶体生长后期采取长时间的原位恒温退火. 采用红外透射显微镜、I-V 特性曲线以及多道能谱仪测试经过原位退火后的晶体内部Te 夹杂相分布、电阻率大小以及能谱响应. 结果表明, 原位退火可以大幅降低CZT 晶体内部大尺寸Te 夹杂相的密度, 晶体内绝大部分的Te 夹杂都集中在5 μm 以内. 此外, 原位退火后的晶体电阻率从4.54×108 Ω·cm上升至3.73×1010 Ω·cm. 原位退火后的CZT晶体对 241Am@59.5 keV 射线表现出了良好的能量分辨率, 为7.29%.
CdZnTe (CZT) single crystals were grown by a modified vertical Bridgman method. After the growth was completed, the crystals were annealed at a constant temperature for a long time. Infrared microscope, I-V characteristic curves, and multi-channel spectrometer were employed to analyze Te inclusions distribution in the crystal, electrical resistivity and spectroscopy response of CZT wafers. The results show that in-situ annealing can greatly decrease concentration of Te inclusions, and most of the Te inclusion sizes are less than 5 μm. In addition, electrical resistivity of CZT is increased from 4.54×108 to 3.73×1010 after annealing. The 241Am@59.5 keV keV keV-ray pulse height spectra of CZT crystal after in-situ annealing reaches 7.29%.
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