The combination of van der Waals heterostructures by stacking different kinds of two-dimensional structures is an effective method to design optoelectronic devices. In this work, the electronic and optical properties of vertically stacked Si/InS heterostructures are investigated by using density functional theory. We check the dynamical stability of all possible bilayer configurations of Si/InS and only stable stackings are taken into account for the analysis of electronic and optical properties. The stacking-dependent band structures are calculated together with their alignment by regarding the contribution of layers that construct the heterostructure. The band alignment of the heterobilayer systems suggests type-I and type-II heterostructure formation according to their stacking pattern. The charge transfer between layers and work function of heterobilayers is also analyzed. We find that the Si/InS heterostructure forms an n-type Schottky contact with stacking-dependent Schottky barrier height of ∼\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim$$\end{document}0.6–0.06 eV. Moreover, the effects of the perpendicular electric field were investigated on the electronic properties of Si/InS heterobilayers. Furthermore, it is shown that Schottky barrier height can be efficiently tuned by the variation of external electric field. The Si/InS heterostructure keeps a n-type Schottky contact for the all electric field values whereas the magnitude and the direction of the electric field enable the possibility of transformation between Schottky contact and ohmic contact at the Si/InS interface. Finally, the optical properties of Si/InS are also examined as part of density functional theory calculations by considering the imaginary part of the dielectric function. Here it is shown that absorption spectrum strongly depends on the stacking patterns of Si/InS heterostructure and these structures include strong prominent absorption peaks over the infrared and ultraviolet range. These results presented that Si/InS bilayer heterostructures may provide helpful information for the design and the fabrication of silicene-based two-dimensional van der Waals heterostructures that can be good candidates for tunable optoelectronics applications.

中文翻译：

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能量稳定的Si/InS范德华异质双层光电特性的第一性原理研究

通过堆叠不同种类的二维结构来组合范德华异质结构是设计光电器件的有效方法。在这项工作中，使用密度泛函理论研究了垂直堆叠的 Si/InS 异质结构的电子和光学性质。我们检查了所有可能的 Si/InS 双层配置的动态稳定性，并且在分析电子和光学特性时只考虑了稳定的堆叠。通过考虑构建异质结构的层的贡献，计算依赖于堆叠的带结构及其排列。异质双层系统的能带排列表明根据其堆叠模式形成 I 型和 II 型异质结构。还分析了层间的电荷转移和异质双层的功函数。我们发现 Si/InS 异质结构形成 n 型肖特基接触，与堆叠相关的肖特基势垒高度为∼\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{ amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim$$\end{document}0.6–0.06 eV。此外，研究了垂直电场对 Si/InS 异质双层电子特性的影响。此外，还表明肖特基势垒高度可以通过外部电场的变化有效地调整。Si/InS 异质结构在所有电场值下保持 n 型肖特基接触，而电场的大小和方向使 Si/InS 界面处的肖特基接触和欧姆接触之间的转换成为可能。最后，通过考虑介电函数的虚部，还检查了 Si/InS 的光学特性，作为密度泛函理论计算的一部分。这里表明吸收光谱强烈依赖于 Si/InS 异质结构的堆叠模式，这些结构包括在红外和紫外范围内的强烈突出吸收峰。