Silicene is recognized as a promising candidate of two-dimensional (2D) materials replacing bulk silicon in the post-CMOS era, because of its compatibility with silicon-based technologies. However, the Dirac-cone band structure, because of the honeycomb lattice, prevents pristine silicene from being applied as a semiconductor in electronic devices. Here, we propose a 2D-silicon semiconductor by introducing kagome topology into the honeycomb lattice, i.e., a hybrid honeycomb-kagome (hhk) structure that is referenced as hhk-silicene. Our first-principles calculations demonstrate the high geometric stability and excellent semiconducting properties of the hhk-silicene, which opens up an electronic bandgap comparable to that of the bulk silicon and bears an electron mobility as high as that of the honeycomb silicene. By designing a field-effect transistor based on the hhk-silicene, giant negative differential resistance and switching performance fulfilling the requirements of ITRS (International Technology Roadmap for Semiconductors) are predicted. This work opens up the possibility of rational design of 2D-silicon semiconductors by focusing on the topological lattice structures.

中文翻译：

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半导体硅烯：具有混合蜂窝-Kagome 晶格的二维硅同素异形体

硅烯被认为是后 CMOS 时代替代体硅的二维 (2D) 材料的有前途的候选者，因为它与硅基技术兼容。然而，由于蜂窝晶格的狄拉克锥带结构，阻止了原始硅烯在电子设备中用作半导体。在这里，我们通过将 kagome 拓扑引入蜂窝晶格，即混合蜂窝-kagome (hhk) 结构，被称为 hhk-silicene，提出了一种 2D 硅半导体。我们的第一性原理计算证明了 hhk-硅烯的高几何稳定性和优异的半导体性能，它开辟了与体硅相当的电子带隙，并具有与蜂窝状硅一样高的电子迁移率。通过设计基于 hhk-silicene 的场效应晶体管，预测了满足 ITRS（国际半导体技术路线图）要求的巨大负差分电阻和开关性能​​。这项工作通过关注拓扑晶格结构开辟了合理设计二维硅半导体的可能性。