Chalcogenide thin films are exciting candidates for electronic applications such as spintronic devices, non-volatile memories and thermoelectric materials. To achieve such applications the understanding of their thin film growth is of paramount importance. In this work the epitaxy of exemplary chalcogenides Sb₂Te₃ and GeTe on different surfaces of Si(111) with atomically sharp interfaces is presented and compared using plan-view transmission electron microscopy and electron diffraction. It is shown that depending on the monolayer surface termination the resulting films present drastic differences in terms of film morphology and crystallinity. In particular, a profound difference is found between the films grown on H-passivated and Sb-passivated surfaces. In both cases, the out-of-plane texture is strongly c-axis oriented, but the case of Si(111)–H shows the frequent occurrence of random in-plane twist for both films, while for Si(111)–Sb this is strongly suppressed. The role of the substrate-film interface for the epitaxy is discussed and the consequences for the properties of the films are highlighted. In general, the insights of these results shed light on chalcogenide thin film growth for topological insulator, ferroelectric, thermoelectric and phase-change materials research.

中文翻译：

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使用表面钝化 调整Sb ₂ Te ₃和GeTe薄膜的外延†

硫族化物薄膜是电子应用中令人兴奋的候选材料，例如自旋电子器件，非易失性存储器和热电材料。为了实现这样的应用，对它们的薄膜生长的理解是至关重要的。在这项工作中，示例性硫族化物Sb ₂ Te ₃的外延用平面透射电子显微镜和电子衍射技术，比较了Si（111）具有原子尖锐界面的Si和Si不同表面上的GeTe和GeTe，并进行了比较。结果表明，取决于单层表面终止，所得膜在膜形态和结晶度方面存在巨大差异。特别地，在H钝化和Sb钝化的表面上生长的膜之间发现了巨大的差异。在这两种情况下，外的平面纹理强烈Ç轴取向，但Si（111）–H的情况表明两层膜都经常发生随机的面内扭曲，而Si（111）–Sb的情况则受到强烈抑制。讨论了衬底-膜界面对于外延的作用，并突出了对膜性能的影响。通常，这些结果的见解为拓扑绝缘体，铁电，热电和相变材料研究提供了硫族化物薄膜生长的方法。