2D-CrOCl各向异性的力学和电子性质的第一性原理研究

Mechanical and Electronic Properties of Anisotropic 2D-CrOCl: The First-Principles Study

摘要: 在本文中，我们基于密度泛函理论的第一性原理的方法计算了二维自旋半导体单层CrOCl的机械力学性质，载流子迁移率和应变下的电子性质。各向异性的晶体结构导致单层CrOCl具有各向异性的力学性质和载流子迁移率。单层CrOCl的杨氏弹性模量各向异性比为1.62，泊松比的各向异性比为2.72。我们的结果显示，沿x方向的载流子迁移率远高于沿y方向的，载流子迁移率的各向异性比分别为20.47 (电子)和24.32 (空穴)。当分别沿x和y方向施加−8%~8%的单轴应变时，我们发现单层CrOCl的电子能带结构会发生明显变化，价带顶或导带底的位置会发生改变。我们的工作为未来进一步调控单层CrOCl的光电性质和纳米自旋电子器件方面的应用提供了理论依据。

Abstract: In this paper, we have employed the first-principles method based on density functional theory to calculate the mechanical, carrier mobility, and electronic properties under strain of monolayer CrOCl, a two-dimensional spin semiconductor. The anisotropic crystal structure of mono-layer CrOCl gives rise to its anisotropic mechanical properties and carrier mobility. The anisotropic ratio of Young’s modulus for monolayer CrOCl is 1.62, while the anisotropic ratio of Poisson’s ratio is 2.72. Our results demonstrate a significant anisotropy in carrier mobility, with the carrier mobility along the x-direction being much higher than that along the y-direction, with an anisotropic ratio of 20.47 (electrons) and 24.32 (holes). Furthermore, we observed a significant variation in the electronic band structure of monolayer CrOCl under uniaxial strains ranging from −8% to 8% applied along the x and y directions, leading to a change in the position of the valence band maximum or conduction band minimum. Our findings provide a theoretical basis for future manipulation of the optoelectronic properties and nanoscale spin electronic devices of monolayer CrOCl.