Pham Khang D
Institute of Applied Technology, Thu Dau Mot University Binh Duong Province 75000 Vietnam
RSC Adv. 2021 Nov 15;11(58):36682-36688. doi: 10.1039/d1ra07813e. eCollection 2021 Nov 10.
The breaking of the vertical mirror symmetry in two-dimensional Janus structures has given rise to many outstanding features that do not exist in the original materials. In this work, we study the structural, mechanical, and electronic properties of Janus GeSnX (X = S, Se, Te) single-layers using density functional theory. The stability of the investigated Janus structures has been tested through the analysis of their phonon dispersions and elastic parameters. It is found that, with low in-plane stiffness, Janus GeSnX single-layers are more mechanically flexible than other two-dimensional materials and their mechanical properties exhibit very high anisotropy. All three single-layers are semiconductors and their bandgap can be altered easily by strain engineering. Due to the asymmetric structure, a vacuum level difference between the two sides is observed, leading to the difference in work function on the two sides of single-layers. Our findings not only provide necessary information about the physical properties of Janus GeSnX single-layers but also provide the impetus for further studies on these interesting materials both theoretically and experimentally.
二维Janus结构中垂直镜像对称性的打破产生了许多原始材料中不存在的突出特性。在这项工作中，我们使用密度泛函理论研究了Janus GeSnX（X = S、Se、Te）单层的结构、力学和电子性质。通过分析所研究Janus结构的声子色散和弹性参数，测试了它们的稳定性。结果发现，Janus GeSnX单层具有较低的面内刚度，比其他二维材料在力学上更具柔韧性，并且它们的力学性能表现出非常高的各向异性。所有这三种单层都是半导体，并且它们的带隙可以通过应变工程轻松改变。由于结构不对称，观察到两侧之间存在真空能级差，导致单层两侧的功函数不同。我们的发现不仅提供了有关Janus GeSnX单层物理性质的必要信息，还为在理论和实验上对这些有趣材料的进一步研究提供了动力。
