Ab initio density functional theory study on the atomic and electronic structure of GaP/Si(001) heterointerfaces
Ab initio density functional theory study on the atomic and electronic structure of GaP/Si(001) heterointerfaces
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GaP/Si(001)异质界面原子电子结构从头算密度泛函理论研究
DOI：
10.1103/physrevb.94.155309
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发表时间：
2016
影响因子：
3.7
通讯作者：
T. Hannappel
中科院分区：
文献类型：
--
作者：
O. Romanyuk;O. Supplie;T. Susi;M. M. May;T. Hannappel
用从头算方法研究了GaP/Si(001)异质界面的原子和电子能带结构。计算了几个GaP层内具有Si替代位的突变界面和混合界面的相对总能量。研究发现，Si在第一界面层以上的GaP层中的扩散在能量上是不利的。在热力学平衡下，在Si衬底上方的第一层具有Si/Ga替代位的界面是最稳定的界面。表面重构终止的外延GaP/Si(001)异质结的电子能带结构由两个半导体的公共带隙中的表面电子态和界面电子态组成。态的色散是各向异性的，对于突变的Si-Ga、Si-P和混合界面，状态的色散是不同的。计算了突变的和能量最低的异质界面结构的Ga、P和Sicore能级的结合能位移。对于突变的Si-Ga和Si-P界面，分别预测了界面异价键引起的芯能级负移和正向位移。异质界面电子结构和芯能级位移的显著特征为掩埋的极性对非极性半导体异质界面的实验表征开辟了新的视角。
The atomic and electronic band structures of GaP/Si(001) heterointerfaces were investigated byab initiodensity functional theory calculations. Relative total energies of abrupt interfaces and mixed interfaces with Si substitutional sites within a few GaP layers were derived. It was found that Si diffusion into GaP layers above the first interface layer is energetically unfavorable. An interface with Si/Ga substitution sites in the first layer above the Si substrate is energetically the most stable one in thermodynamic equilibrium. The electronic band structure of the epitaxial GaP/Si(001) heterostructure terminated by thesurface reconstruction consists of surface and interface electronic states in the common band gap of two semiconductors. The dispersion of the states is anisotropic and differs for the abrupt Si-Ga, Si-P, and mixed interfaces. Ga, P, and Sicore-level binding-energy shifts were computed for the abrupt and the lowest-energy heterointerface structures. Negative and positive core-level shifts due to heterovalent bonds at the interface are predicted for the abrupt Si-Ga and Si-P interfaces, respectively. The distinct features in the heterointerface electronic structure and in the core-level shifts open new perspectives in the experimental characterization of buried polar-on-nonpolar semiconductor heterointerfaces.