Faculty of Physics, TNU-University of Education, Thai Nguyen, Vietnam.
Institute of Physics, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
Phys Chem Chem Phys. 2023 May 24;25(20):14502-14510. doi: 10.1039/d3cp00828b.
Seamlessly stitching two-dimensional (2D) materials may lead to the emergence of novel properties triggered by the interactions at the interface. In this work, a series of 2D lateral heterostructures (LHSs), namely germanene-arsenene (Ge-As) and germanene-antimonene (Ge-Sb), are investigated using first-principles calculations. The results demonstrate a strong interline-dependence of the electronic and magnetic properties. Specifically, the LHS formation along an armchair line preserves the non-magnetic nature of the original materials. However, this is an efficient approach to open the electronic band gap of the germanene monolayer, where band gaps as large as 0.74 and 0.76 eV are induced for Ge-As and Ge-Sb LHSs, respectively. Meanwhile, magnetism may appear in the zigzag-LHSs depending on the chemical composition ( = 3, 4, 5, and 6 for germanene-arsenene and = 2, 3, 4, 5, and 6 for germanene-antimonene), where total magnetic moments between 0.13 and 0.50 are obtained. Herein, magnetic properties are produced mainly by the spin-up state of Ge atoms at the interface, where a small contribution comes from As(Sb) atoms. Spin-resolved band structures show a multivalley profile in both the valence band and the conduction band with a topological insulator-like behavior, where the interface states are derived mainly from the interface Ge-p state. The results introduce new 2D lateral heterostructures with novel electronic and magnetic properties to allow new functionalities, which could be further explored for optoelectronic and spintronic applications.
无缝拼接二维（2D）材料可能会导致界面相互作用引发新的性质出现。在这项工作中，使用第一性原理计算研究了一系列二维横向异质结构（LHS），即锗烯-砷烯（Ge-As）和锗烯-锑烯（Ge-Sb）。结果表明电子和磁性性质强烈依赖于线的方向。具体来说，沿扶手椅线形成的 LHS 保持了原始材料的非磁性性质。然而，这是打开锗烯单层带隙的有效方法，其中 Ge-As 和 Ge-Sb LHS 分别诱导了 0.74 和 0.76 eV 的带隙。同时，根据化学成分（对于锗烯-砷烯， = 3、4、5 和 6；对于锗烯-锑烯， = 2、3、4、5 和 6），锯齿形-LHS 中可能会出现磁性，其中获得了 0.13 到 0.50 的总磁矩。在这里，磁性主要是由界面处 Ge 原子的自旋向上状态产生的，其中 As(Sb) 原子的贡献很小。自旋分辨能带结构在价带和导带中都显示出多谷轮廓，具有拓扑绝缘体样行为，其中界面态主要来自界面 Ge-p 态。这些结果引入了具有新型电子和磁性性质的新二维横向异质结构，以允许实现新功能，这些功能可进一步探索用于光电和自旋电子应用。
