Nguyen Chuong V, Hieu Nguyen N, Nguyen Duong T
Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Da Nang, Vietnam.
School of Mechanical Engineering, Le Quy Don Technical University, Hanoi, Vietnam.
Nanoscale Res Lett. 2015 Dec;10(1):433. doi: 10.1186/s11671-015-1099-5. Epub 2015 Nov 4.
Strain-dependent structural and electronic properties of MoS2 materials are investigated using first principles calculations. The structural and electronic band structures of the MoS2 with relaxed unit cells are optimized and calculated by the dispersion-corrected density functional theory (DFT-D2). Calculations within the local density approximation (LDA) and GGA using PAW potentials were also performed for specific cases for the purpose of comparison. The effect of strain on the band gap and the dependence of formation energy on strain of MoS2 are also studied and discussed using the DFT-D2 method. In bulk MoS2, the orbitals shift towards the higher/lower energy area when strain is applied along the z/x direction, respectively. The energy splitting of Mo4d states is in the range from 0 to 2 eV, which is due to the reduction of the electronic band gap of MoS2.
采用第一性原理计算方法研究了MoS2材料的应变相关结构和电子性质。利用色散校正密度泛函理论（DFT-D2）对具有弛豫晶胞的MoS2的结构和电子能带结构进行了优化和计算。为了进行比较，还针对特定情况采用投影增强波（PAW）势在局域密度近似（LDA）和广义梯度近似（GGA）下进行了计算。还使用DFT-D2方法研究并讨论了应变对MoS2带隙的影响以及形成能对应变的依赖性。在体相MoS2中，当沿z/x方向施加应变时，轨道分别向更高/更低能量区域移动。Mo4d态的能量分裂在0到2 eV范围内，这是由于MoS2电子带隙的减小所致。
