Scattering-theoretical method for semiconductor surfaces: Self-consistent formulation and application to Si(001)-(2 x 1).
Scattering-theoretical method for semiconductor surfaces: Self-consistent formulation and application to Si(001)-(2 x 1).
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半导体表面的散射理论方法：自洽公式及其在 Si(001)-(2 x 1) 上的应用。
DOI：
10.1103/physrevb.38.10578
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Pollmann
中科院分区：
文献类型：
--
作者：
Krüger;Pollmann
本文详细介绍了半无限晶体表面重构的自洽场方法，并将其应用于Si（001）-（2× 1）表面。该方法是基于局域密度泛函理论和格林函数散射理论制定。波函数和算子表示在局部高斯轨道基组。计算产生的自洽表面电位，电荷密度，表面能带结构，波矢，原子和轨道分辨层密度的状态与极端的光谱分辨率。表面束缚态和表面共振的确定明确和准确，即使是波函数非常扩展的状态。为了能够指出我们的方法与其他技术的结果相比的优势，我们进行了自洽板计算，以及不同的板厚度。本方法被证明是非常有效和准确地描述整个电子光谱的表面。该方法的效率很大程度上源于这样一个事实，即它利用了充分的三维周期性的基础散装晶体和短期的偏差的表面电位从散装或真空电位，分别。因此，所有的本体属性从一开始就通过能带结构计算作为一个明确的参考，并保留下来。然后，人们集中在表面电位产生的变化。由于体效应和表面效应在表面绿色函数的Dyson方程中被解析分离，因此结果的解释是直接和明确的。通过详细讨论我们对技术上最重要的Si（001）-（2× 1）表面的结果，并与我们自己的平板计算和文献中的其他结果进行比较，说明了散射理论方法的优点。
A self-consistent-field method for the calculation of electronic properties of semi-infinite crystals with reconstructed surfaces is described in detail and applied to the Si (001)-(2× 1) surface. The method is based on local-density-functional theory and a Green-function scattering-theoretic formulation is employed. Wave functions and operators are represented in a localized-Gaussian-orbital basis set. The calculations yield the self-consistent surface potential, charge densities, surface band structure, and wave-vector-, atom-, and orbital-resolved layer densities of states with an extreme spectral resolution. Surface bound states and surface resonances are determined unambiguously and accurately even for states whose wave functions are very extended. In order to be able to point out advantages of our method by comparison with the results of other techniques, we have carried out self-consistent slab calculations with varying slab thicknesses as well. The present method is shown to be very efficient and accurate in describing the whole electronic spectrum of the surface. The efficiency of the method stems largely from the fact that it exploits both the full three-dimensional periodicity of the underlying bulk crystal and the short range of the deviation of the surface potential from the bulk or vacuum potentials, respectively. Thus all bulk properties are built in from the start via a band-structure calculation as a well-defined reference and they are preserved. One then focuses on the changes produced by the surface potential. Since the bulk and surface effects are separated analytically in the Dyson equation for the surface Green function, the interpretation of the results is straightforward and unambiguous. The virtues of the scattering-theoretical method are exemplified by a detailed discussion of our results for the technologically most important Si (001)-(2× 1) surface in comparison with our own slab calculations and with other results from the literature.