Key Laboratory of Advanced Display Materials and Devices, Ministry of Industry and Information Technology, College of Material Science and Engineering, Nanjing University of Science and Technology , Nanjing 210094, China.
Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig , Linnéstrasse 2, 04103 Leipzig, Germany.
Nano Lett. 2017 Jun 14;17(6):3434-3440. doi: 10.1021/acs.nanolett.7b00297. Epub 2017 May 3.
Highly stable antimonene, as the cousin of phosphorene from group-VA, has opened up exciting realms in the two-dimensional (2D) materials family. However, pristine antimonene is an indirect band gap semiconductor, which greatly restricts its applications for optoelectronics devices. Identifying suitable materials, both responsive to incident photons and efficient for carrier transfer, is urgently needed for ultrathin devices. Herein, by means of first-principles computations we found that it is rather feasible to realize a new class of 2D materials with a direct bandgap and high carrier mobility, namely antimonene oxides with different content of oxygen. Moreover, these tunable direct bandgaps cover a wide range from 0 to 2.28 eV, which are crucial for solar cell and photodetector applications. Especially, the antimonene oxide (18Sb-18O) is a 2D topological insulator with a sizable global bandgap of 177 meV, which has a nontrivial Z topological invariant in the bulk and the topological states on the edge. Our findings not only introduce new vitality into 2D group-VA materials family and enrich available candidate materials in this field but also highlight the potential of these 2D semiconductors as appealing ultrathin materials for future flexible electronics and optoelectronics devices.
如同磷烯一样，作为第五主族的一员，本征锑烯是一种非常稳定的二维（2D）材料，在 2D 材料家族中开辟了令人兴奋的领域。然而，本征锑烯是一种间接带隙半导体，这极大地限制了它在光电器件中的应用。对于超薄器件而言，急需寻找既能响应入射光子又能高效载流子输运的合适材料。在此，我们通过第一性原理计算发现，实现一类具有直接带隙和高载流子迁移率的新型 2D 材料是可行的，即具有不同氧含量的锑烯氧化物。此外，这些可调谐的直接带隙覆盖了从 0 到 2.28eV 的很宽范围，这对于太阳能电池和光电探测器的应用至关重要。特别是，锑烯氧化物（18Sb-18O）是一种二维拓扑绝缘体，具有 177meV 的可观全局带隙，在体相中具有非平凡的 Z 拓扑不变量，在边缘具有拓扑态。我们的研究结果不仅为 2D 第五主族材料家族带来了新的活力，丰富了该领域的候选材料，还突出了这些二维半导体作为未来柔性电子学和光电子学器件有吸引力的超薄材料的潜力。
