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
Application of Cluster Expansion and Average-bond-energy Method to In_x.Ga_(1-x)As/GaAs System
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...