Effects of annealing on the properties of CdZnTe epitaxial thick films deposited on p-GaAs using close-spaced sublimation
Effects of annealing on the properties of CdZnTe epitaxial thick films deposited on p-GaAs using close-spaced sublimation
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DOI：
10.1016/j.nima.2021.165752
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发表时间：
2021-11
影响因子：
1.4
通讯作者：
Yang Li;K. Cao;G. Zha;Wenyu Zhang;Li Yiwei;Xin Wan;W. Jie
中科院分区：
文献类型：
--
作者：
Yang Li;K. Cao;G. Zha;Wenyu Zhang;Li Yiwei;Xin Wan;W. Jie
采用近空间升华法在p型GaAs（001）衬底上制备了CdZnTe外延厚膜。为了减少CdZnTe/p-GaAs薄膜中的缺陷，提高载流子输运性能，在Te 2气氛中进行了等温退火.退火后，CdZnTe/p-GaAs样品的电阻率增大，漏电流减小。此外，采用全峰通道对不同电压下的241Am@5.49MeV α粒子能谱进行Hecht方程拟合，得到的电子迁移率和寿命积μ τ e得到了改善。最后，获得了退火CdZnTe/p-GaAs样品的241Am@59.5keV γ能谱。根据腐蚀坑密度和光致发光光谱，表明等温退火降低了CdZnTe薄膜中的位错密度，从而提高了退火后探测器的性能。
CdZnTe epitaxial thick films were deposited on p-type GaAs (001) substrates using close-spaced sublimation. In order to reduce defects in the CdZnTe/p-GaAs films and improve the carrier transport properties, isothermal annealing in a Te 2 atmosphere was carried out. After annealing, the resistivity of the CdZnTe/p-GaAs samples increased and the leakage current decreased. In addition, the electron mobility and lifetime product μ τ e, measured by fitting 241 Am@ 5.49 MeV α particles energy spectra with the Hecht equation using full peak channels under different voltages, were improved. Finally, a 241 Am@ 59.5 keV γ ray energy spectrum of an annealed CdZnTe/p-GaAs sample was acquired. According to the etch pit density and photoluminescence spectrum, it was suggested that isothermal annealing reduced the dislocation density in the as-deposited CdZnTe films and therefore improved the performance of the annealed detectors.