In掺杂对MVB-Te溶剂法生长的ZnTe晶体光电性能的影响  

Effects of In Doping on the Optical and Electrical Properties of ZnTe Crystal Grown by MVB-Te Solvent Method

作　　者：刘航[1] 介万奇[1] 徐亚东[1] 杨睿[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《人工晶体学报》2014年第5期1023-1028,1036,共7页Journal of Synthetic Crystals

基　　金：国家自然科学基金(51202197);国家重点基础研究专项基金(2011CB610406);高等学校博士学科点专项科研基金(20116102120014)

摘　　要：采用Te溶剂结合改进的垂直布里奇曼法(MVB)制备了In∶ZnTe与ZnTe晶体,并对晶体的光学与电学特性进行了表征。通过红外透过显微成像技术观察了In∶ZnTe与ZnTe中的Te夹杂并进行了统计分析,发现In掺杂未对ZnTe中的Te夹杂的分布和尺寸产生显著影响。红外透过光谱分析表明,In∶ZnTe与ZnTe晶体的红外透过率曲线均表现出平直的趋势,且其平均透过率基本相等,约为60%,进一步表明In的掺入并未导致严重的晶格和杂质吸收。然而,I-V测试分析发现,In掺杂使得ZnTe晶体的电阻率提高了5个数量级。同时Hall测试分析表明,In∶ZnTe与ZnTe晶体均为p型导电,In掺杂很大程度上补偿了晶体中的V Zn,使得晶体中的载流子浓度降低了4个数量级。对比了两种晶体的紫外-可见-近红外透过光谱,可以观察到,In掺杂使ZnTe的吸收边从550 nm红移到560nm,这可能是由于In掺杂引入的浅能级导致的吸收边带尾现象造成的。The electrical and optical properties of In： ZnTe and ZnTe crystals grown by MVB-Te solvent method were characterized. Observation and statistical analysis of Te inclusions in In： ZnTe and ZnTe crystals show that In dopant has no significant effect on the distribution and the size of Te inclusions by IRTM （IR transmission microscopy）. Besides, IR transmission spectra of In： ZnTe and ZnTe crystals show flat curves and demonstrate that average transmittances are approximately 60%, which suggests In dopant doesnt result in serious lattice and impurity absorption. However, I-V measurement shows that In dopant increases the resistivity of ZnTe crystal for 5 orders of magnitude. Hall test indicates that In： ZnTe and ZnTe crystals are both p-type. The carrier concentration of In： ZnTe crystal is decreased 4 orders of magnitude due to In dopant compensating on Vzn in the crystal. Comparing UV-Vis-NIR transmission spectra of In： ZnTe and ZnTe crystals, it is suggested that the absorption edge drifts from 550 nm in ZnTe crystal to 560 nm in In： ZnTe crystal, which is possibly attributed to the shallow level defects associated with In dopant leading to the absorption band tail phenomenon.

关 键 词：MVB-Te溶剂法 In掺杂 红外透过显微成像 I-V测试 Hall测试 

分 类 号：O731[理学—晶体学]