2017/11/01 by Nguyen T. Hung, Ahmad R. T. Nugraha, Riichiro Saito · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci
paper · pdf · doi:10.1088/1361-6463/aaa68f
12 pages, 6 figures
arxiv created 2017/11/01 · arxiv updated 2018/02/14
We investigate electromechanical properties of two-dimensional MoS2 monolayers in the 1H, 1T, and 1T^′ structures as a function of charge doping by using density functional theory. We find isotropic elastic moduli in the 1H and 1T structures, while the 1T^′ structure exhibits an anisotropic elastic modulus. Moreover, the 1T structure is shown to have a negative Poisson's ratio, while Poisson's ratios of the 1H and 1T^′ are positive. By charge doping, the monolayer MoS2 shows a reversibly strain and work density per cycle ranging from -0.68% to 2.67% and from 4.4 to 36.9 MJ/m3, respectively, making them suitable for applications in electromechanical actuators. Stress generated is also examined in this work and we find that 1T and 1T^′ MoS2 monolayers relatively have better performance than 1H MoS2 monolayer. We argue that such excellent electromechanical performance originate from the electrical conductivity of the metallic 1T and semimetallic 1T^′ structures high Young's modulus of about 150-200 GPa.