原子集团展开和平均键能方法在In_xGa_（1－x）As／GaAs系统中的应用

Abstract

【中文摘要】 把原子集团展开方法同平均键能方法相结合，建立了一种研究合金型应变层异质界面价带偏移的方法．应用此方法对ＩｎｘＧａ１－ｘＡｓ／ＧａＡｓ系统分别计算了以ＧａＡｓ和以ＩｎｘＧａ１－ｘＡｓ为衬底的两种不同的应变状态下的价带偏移（△Ｅｖ）随合金组份的变化规律．结果表明，由于应变的引入，该系统的面△Ｅｖ～Ｘ表现出大的非线性，且这一关系受到应变状态的显著影响．通过改变应变状态可使其为Ⅰ型或Ⅱ型超晶格以及金属．部分结果与有关的实验值和理论结果相符合． 【英文摘要】 A theoretical method for determining the valence-band offset (VBO) at strained alloy type heterojunctions is presented by combining the cluster expansion method and average-bond-energy method. Adopting this method; the VBO at InxGa1-xAs/GaAs system as a function of the alloy composition x is determined for two different strain conditions. It is shown that this variaton is in large nonlinearity due to the introduction of the elastic strain; and is exceedingly modulated by the strain condition. Present resul...