Yazyev Oleg V, Pasquarello Alfredo
Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Chemical Sciences and Engineering, CH-1015 Lausanne, Switzerland.
Phys Rev Lett. 2006 Apr 21;96(15):157601. doi: 10.1103/PhysRevLett.96.157601. Epub 2006 Apr 19.
Using a first-principles approach, we investigate the origin of the fine structure in Si 2p photoelectron spectra at the Si(100)-(2 x 1) surface and at the Si(100)-SiO2 interface. Calculated and measured shifts show very good agreement for both systems. By using maximally localized Wannier functions, we clearly identify the shifts resulting from the electronegativity of second-neighbor atoms. The other shifts are then found to be proportional to the average bond-length variation around the Si atom. Hence, in combination with accurate modeling, photoelectron spectroscopy can provide a direct measure of the strain field at the atomic scale.
采用第一性原理方法，我们研究了Si(100)-(2×1)表面和Si(100)-SiO₂界面处Si 2p光电子能谱精细结构的起源。计算和测量的位移在两个体系中都显示出非常好的一致性。通过使用最大局域化的Wannier函数，我们清楚地识别出由次近邻原子的电负性引起的位移。然后发现其他位移与Si原子周围平均键长的变化成正比。因此，结合精确的建模，光电子能谱可以在原子尺度上直接测量应变场。
