Department of Electrical and Electronic Engineering, Khulna University of Engineering and Technology, Khulna, 9203, Bangladesh.
School of Physics, The University of Sydney, Sydney, NSW, 2006, Australia.
Sci Rep. 2023 Mar 2;13(1):3532. doi: 10.1038/s41598-023-30601-3.
Crystal deformation mechanisms and mechanical behaviors in semiconductor nanowires (NWs), in particular ZnSe NWs, exhibit a strong orientation dependence. However, very little is known about tensile deformation mechanisms for different crystal orientations. Here, the dependence of crystal orientations on mechanical properties and deformation mechanisms of zinc-blende ZnSe NWs are explored using molecular dynamics simulations. We find that the fracture strength of [111]-oriented ZnSe NWs shows a higher value than that of [110] and [100]-oriented ZnSe NWs. Square shape ZnSe NWs show greater value in terms of fracture strength and elastic modulus compared to a hexagonal shape at all considered diameters. With increasing temperature, the fracture stress and elastic modulus exhibit a sharp decrease. It is observed that the {111} planes are the deformation planes at lower temperatures for the [100] orientation; conversely, when the temperature is increased, the {100} plane is activated and contributes as the second principal cleavage plane. Most importantly, the [110]-directed ZnSe NWs show the highest strain rate sensitivity compared to the other orientations due to the formation of many different cleavage planes with increasing strain rates. The calculated radial distribution function and potential energy per atom further validates the obtained results. This study is very important for the future development of efficient and reliable ZnSe NWs-based nanodevices and nanomechanical systems.
半导体纳米线（NWs）中，特别是 ZnSe NWs 的晶体变形机制和力学行为表现出强烈的各向异性。然而，对于不同晶体取向的拉伸变形机制，人们知之甚少。本文通过分子动力学模拟，研究了纤锌矿型 ZnSe NWs 的晶体取向对力学性能和变形机制的依赖性。研究发现，[111]取向的 ZnSe NWs 的断裂强度高于[110]和[100]取向的 ZnSe NWs。与六边形相比，在所有考虑的直径下，正方形 ZnSe NWs 在断裂强度和弹性模量方面具有更大的价值。随着温度的升高，断裂应力和弹性模量呈现出急剧的下降。结果表明，在较低温度下，[100]取向的变形平面为{111}平面；相反，当温度升高时，{100}平面被激活并作为第二主要解理面起作用。最重要的是，由于应变率增加时形成了许多不同的解理面，[110]取向的 ZnSe NWs 比其他取向具有更高的应变速率敏感性。计算得到的径向分布函数和原子势能进一步验证了所得结果。这项研究对于未来开发高效可靠的基于 ZnSe NWs 的纳米器件和纳米力学系统非常重要。
