Impurities in CdZnTe crystal grown by vertical Bridgman method
Impurities in CdZnTe crystal grown by vertical Bridgman method
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DOI：
10.1016/j.nima.2004.06.135
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发表时间：
2004-12
影响因子：
1.4
通讯作者：
Guoqiang Li;W. Jie;Tao Wang;Ge Yang
中科院分区：
文献类型：
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作者：
Guoqiang Li;W. Jie;Tao Wang;Ge Yang
详细研究了垂直布里奇曼法生长的CdZnTe中的杂质偏析及其对晶体光学和电学性质的影响。电感耦合等离子体质谱分析表明，分凝系数大于1的杂质Al和Ga集中在钢锭的第一次冻结部分，而分凝系数小于1的杂质Li、Na、Mn和Cu则集中在最后一次冻结部分。同时，所有的杂质都在晶界中富集。霍尔测量表明，自由载流子浓度与所有杂质浓度之和之间存在近似的线性单调递增关系，这导致红外透过率随自由载流子吸收引起的杂质富集区波数的增加而增加。电阻率随Li、Na、Cu含量的增加而减小，随Al、Mn、Ga含量的增加而增加。采用退火工艺提取杂质，从而改善了晶体性质。
The impurity segregation in CdZnTe grown by vertical Bridgman method and its corresponding effects on the crystal optical and electrical properties have been studied in detail. Inductively coupled plasma mass spectrometry reveals that impurities Al and Ga with segregation coefficient larger than one centralize in the first-to-freeze portion of the ingot, while impurities Li, Na, Mn, and Cu with segregation coefficient less than one enrich in the last-to-freeze portion of the ingot. At the same time, all impurities enrich in the grain boundaries. Hall measurement indicates that there exists an approximate linear monotonously increasing relationship between the free-carrier density and the sum of all the impurities concentration, which leads to an increase in the infrared transmission with the increase of wave number within the impurity enriching portions caused by the free carrier absorption. It is also found that the resistivity decreases with the concentration of Li, Na, and Cu, but increases with the concentration of Al, Mn, and Ga. An annealing processing is adopted to extract the impurities and therefore improve the crystal properties.