应变层超晶格(ZnSe)_(2n)/(ZnS_xSe_(1-x))_(2n)的电子结构

Electronic Structures of (ZnSe)_(2n)/(ZnS_xSe_(1-x)_2n Strained-Layer Superlattice

本文用LCAO-Recursion方法研究了应变层超晶格(ZnSe)_(2n)/(ZnS_xSe_(1-x))_(2n)(n=1)的电子结构。计算了两种应变组态(赝晶生长,Free-Standing生长)下超晶格总的态密度,各原子的局域和分波态密度。我们发现:带隙E_g、费米能级E_f和原子价随应变的变化而变化;(ZnSe)_(2n)/(ZnS_xSe_(1-x))_(2n)超晶格中离子键和共价键共存;电子在界面附近发生了转移。

The structure and properties of (ZnSe)_(2n)/(ZnS_xSe_(1-x))_2n(n=1) strained-layer superlatticeare investigated by the recursion method in the tight-binding approximation (TBA). The total.local and partial density of states are calculated for two strained configurations:pseudomorphicgrowth and free-standing growth. It is found that the energy gap Eg, Fermi level E_(?)and atomic valence can he changed for different strain. The characters of ionic and covalentbonding are coexistance in (ZnSe)_(2n)/(ZnS_xSe_(1-x))_(2n)SLS.The electrons trarsfer interface fromone side to another.