Forming novel van der Waals (vdW) heterostructures by combining different two-dimensional (2D) materials is significant to achieve more desirable properties. Using first-principles calculations, we demonstrate the electronic and optical properties of the InSe/InTe van der Waals heterostructure. Our results suggest that this heterostructure has an intrinsic type-II band alignment with a direct band gap. The electrons and holes are respectively localized in the InSe and InTe layers. The spatial separation of the lowest energy electron–hole pairs can occur, implying that the InSe/InTe heterostructure is a good candidate for a high-efficiency solar cell. In addition, the optical absorption in heterostructures can be enhanced compared with both of the monolayers. Moreover, tuning of the values with a direct band gap can be induced by applying normal strain, and the band gap exhibits linear variation. Meanwhile, an intrinsic type-II band alignment can be tuned to become type-I, which is suitable for light emission applications. These results indicate that the flexible InSe/InTe vdW heterostructure can provide new ways to utilize two-dimensional materials in future optoelectronic devices.

中文翻译：

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InSe / InTe Van der Waals异质结构对光电子应用的可调电子和光学性质

通过组合不同的二维（2D）材料形成新颖的范德华（vdW）异质结构对于实现更理想的性能非常重要。使用第一性原理计算，我们证明了InSe / InTe van der Waals异质结构的电子和光学性质。我们的结果表明，这种异质结构具有固有的II型能带排列，并具有直接的带隙。电子和空穴分别位于InSe和InTe层中。最低能量的电子-空穴对可能会发生空间分隔，这意味着InSe / InTe异质结构是高效太阳能电池的良好候选者。另外，与两个单层相比，可以增强异质结构中的光吸收。而且，可以通过施加法向应变来诱导具有直接带隙的值的调谐，并且带隙表现出线性变化。同时，固有的II型能带对准可以调整为I型，适用于发光应用。这些结果表明，柔性的InSe / InTe vdW异质结构可以提供在未来的光电器件中利用二维材料的新方法。