室温辐射探测器用CdZnTe晶体生长及其器件制备

Detector Grade CdZnTe Crystal Growth and Device Fabrication

采用改进的垂直布里奇曼法生长了直径为60 mm的碲锌镉晶体,晶体利用率达到70%以上。晶体中Te沉淀/夹杂密度小于1×10-3cm2,电阻率达到4×1010Ω.cm。利用得到的晶体制备了平面型单元探测器,测量了对不同能量射线的分辨率,其中对241Amγ能谱的分辨率达到4.7%,对137Cs能谱的分辨率为4.2%。采用Hecht公式对探测器收集效率与偏压的关系进行了拟合,得到电子的迁移率与寿命乘积值达到2.3×10-3cm2/V。

CdZnTe crystals with diameter of 60 mm were grown by using Modified Vertical Bridgman method.The yield of the ingots was improved to be over 70%.The density of Te precipitates lower than 1×103 cm-2 and the resistivity up to 4×1010 Ω·cm were determined.Single element planar detectors were fabricated.Spectra response of the detectors to different radiation resources were observed,where the resolution of the 241Am γ-ray spectrum at 59.5 KeV is up to 3.95%.The value of μτ was evaluated by using Hecht equation,which is 2.3×10-3 cm2/V for the electron of the as-grown crystal.