We present a structural and density-functional theory study of the interface of the quasi-twin-free grown three-dimensional topological insulator ${\mathrm{Bi}}_2{\mathrm{Te}}_3$ on Ge(111). Aberration-corrected scanning transmission electron microscopy and electron energy-loss spectroscopy in combination with first-principles calculations show that the weak van der Waals adhesion between the ${\mathrm{Bi}}_2{\mathrm{Te}}_3$ quintuple layer and Ge can be overcome by forming an additional Te layer at their interface. The first-principles calculations of the formation energy of the additional Te layer show it to be energetically favorable as a result of the strong hybridization between the Te and Ge.

中文翻译：

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在Bi2Te3和Ge（111）界面处范德华相互作用的修饰

我们提出了一种准双生长的三维拓扑绝缘体的界面的结构和密度泛函理论研究 ${双}_2{特}_3$在Ge（111）上。像差校正扫描透射电子显微镜和电子能量损失谱结合第一性原理计算表明，两者之间的弱范德华附着力${双}_2{特}_3$可以通过在它们的界面处形成一个额外的Te层来克服五层和Ge的问题。附加的Te层的形成能的第一性原理计算表明，由于Te和Ge之间强烈的杂化，它在能量上是有利的。