红外光电子材料碲镉汞异质外延结构理论研究  

The Theoretical Study of the Hetero-epitaxial Growth for the Infrared Optoelectronic Material HgCdTe

作　　者：陈效双[1] 孙立忠[1] 黄燕[1] 段鹤[1] 陆卫[1] 

机构地区：[1]中国科学院上海技术物理研究所红外物理国家重点实验室,上海200083

出　　处：《激光与红外》2005年第11期837-841,共5页Laser & Infrared

基　　金：国家自然科学基金重点项目(10234040);国家自然科学基金(60221502;60476040);上海市科学技术委员会重点基金(02DJ14066);国家重点基础研究发展规划项目(2001CB610407)资助

摘　　要：文章介绍了基于第一性原理的LAPW方法就Hg空位缺陷对碲镉汞材料的电子结构的影响进行了研究。首先选择Hg0.5Cd0.5Te体系详细分析了Hg空位引起的弛豫,包含Hg空位缺陷体系的电荷密度、成键电荷密度和态密度,得到了碲镉汞材料形成Hg空位情况下的空位第一近邻阴离子悬挂键重整的形式以及Hg空位所形成的双受主能级。计算发现了Hg空位引起第一近邻Te原子5s态能级向高能端移动的现象。同时,对实验中通常利用As钝化基底表面来有效地控制外延生长的极性进行了研究。本文也介绍了基于密度泛函理论模拟了单个及多个As原子在Si(211)重构表面上的吸附、置换行为,通过系统地计算各种可能的吸附、置换构型,并进一步分析能量、键长等性质,对As在Si(211)表面的钝化机理进行了初步研究探讨。对Cd、Te在As钝化前后Si(211)表面上的吸附行为也进行了研究分析,为外延生长实验中利用As钝化来保证B面极性的做法提供了一定的理论依据。The first principle methods is used to study the effects of the most important defects and impurities on the properties of the HgCdTe materials. The relaxation calculations indicate that the nearest neighbor Te around the Hg vacancy defect contract toward to the defect site. The contract relaxation is attributed to the concentration of the electrons around the defect site accompanying the dangling bond reconstruction. From calculated results of DOS, it is found that the Hg vacancy defect produces double acceptors. Meanwhile, we have found that the energy of 5s state of the nearest neighbor Te shift up as the dangling bond reconstruction. At the same time,the adsorption and replacement behaviors of arsenic on the reconstructed Si（ 211 ） surface have been simulated by the DFT. By calculating several possible structures as well as analyzing the energies and bond lengths ,the passivation of the arsenic on the Si surface is studied. Then,the adsorption behaviors of tellurium and cadmium on the clean and As -passivated Si（ 211 ） surface are investigated. The simulation results have some important roles in the growth of Si （211 ） surface passivated by As.

关 键 词：碲镉汞 汞空位 第一性原理方法 硅表面重构 砷钝化 镉吸附 碲吸附 

分 类 号：O471[理学—半导体物理] TN304.25[理学—物理]