多元合金异质结In_xGa_(1-x)As/In_xAl_(1-x)As的价带偏移

Valence band Offset of Multicomponent Alloy type In x Ga 1- x As/In x Al 1- x As Heterojunction

采用ＬＭＴＯ－ＡＳＡ能带计算方法，研究三元合金ＩｎｌＧａ４－ｌＡｓ４和ＩｎｌＡｌ４－ｌＡｓ４（ｌ＝０，１，２，３，４等五个有序态）的能带结构和平均键能Ｅｍ；在此基础上，将原子集团展开与平均键能方法结合起来计算了ＩｎｘＧａ１－ｘＡｓ／ＩｎｘＡｌ１－ｘＡｓ异质结的价带偏移ΔＥｖ（ｘ）值．研究表明：该异质结的ΔＥｖ（ｘ）值随合金组分ｘ的变化接近于线性；ΔＥｖ（ｘ）的理论计算值与实验结果相当符合．

LMTO band method is introduced into calculating the band structures and the average bond energies E m of the five ordered structures in In l Ga 4- l As 4 and In l Al 4- l As 4( l =0,1,2,3,4); the valence band offsets ΔE v(x) as a function of the alloy composition x of the heterojunction In x Ga 1- x As/In x Al 1- x As is studied, by using the average bond energy theory in conjunction with a cluster expansion method. It is shown that the variation of ΔE v(x) is near linear and the calculation results are in very good agreement with relevant experimental data.