Hg_(1-x)Cd_xTe 中杂质对及双空位深能级的研究  

STUDY ON THE DEEP LEVELS OF IMPURITY PAIRS AND VACANCY PAIR IN Hg 1- x Cd x Te

作　　者：刘晓华[1] 介万奇[1] 刘俊诚[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室

出　　处：《航空学报》1998年第1期62-67,共6页Acta Aeronautica et Astronautica Sinica

摘　　要：以Ａ．Ｋｏｂａｙａｓｈｉ等的半经验紧束缚模型和Ｈｊａｌｍａｒｓｏｎ－Ｖｏｇｈ－Ｗｏｌｆｏｒｄ－Ｄｏｗ深能级理论为基础，计算了Ｈｇ１－ｘＣｄｘＴｅ中阳离子位替代式杂质（包括Ｎ，Ｏ，Ｃ）与最近邻替代式杂质形成ｓｐ３键杂质对后阳离子位杂质Ａ１对称性深能级的变化以及最近邻理想双空位（Ｖｃ，Ｖａ）的深能级。计算结果表明：阳离子位杂质Ａ１能级的变化取决于与其配对杂质的电负性，杂质对ａ１能级组分依赖关系ｄＥ／ｄｘ小于阳离子位单杂质Ａ１能级的ｄＥ／ｄｘ，大于阴离子位单杂质Ｔ２能级的ｄＥ／ｄｘ，不同杂质对的ｄＥ／ｄｘ基本相同；理想双空位（Ｖｃ，Ｖａ）在能隙或近能隙区域产生一个ａ１态深能级，该能级的ｄＥ／ｄｘ很小，对于ＣｄＴｅ，位置在０．５ｅＶ，对于ｘ＜０．３７的Ｈｇ１－ｘＣｄｘＴｅ，该能级成为导带共振态。On the basis of the semiempirical tight binding model of A.Kobayashi et al and Hjalmarson Vogl Wolford Dow theory of deep levels, in Hg 1- x Cd x Te, the deep level of ideal vacancy pair ( V c, V a) as well as the variation of the A 1 symmetric deep level of cation site substitutional impurities (N,O,C) when they are paired with nearest neighbor sp 3 bonded substitutional impurities is calculated. The results of this calculation show that the variation of the A 1 level of a cation site impurity depends on the electronegativity of its paired impurity. The energy level composition dependence ( d E/ d x) of the a 1 level of an impurity pair is smaller than that of the A 1 level of isolated cation site impurity, but is larger than that of the T 2 level of an isolated anion site impurity. Different impurity pairs have almost the same  d E/ d x. The ideal vacancy pair ( V c, V a) introduces an a 1 symmetric level with very small  d E/ d x near or in the band gap. For CdTe, its magnitude is about 0.5eV in CdTe. In Hg 1- x Cd x Te ( x <0.37), the level becomes a resonant state in conduction band.

关 键 词：深能级 杂质对 双空位 汞镉碲 红外材料 

分 类 号：TN213[电子电信—物理电子学]