Charge-induced electromechanical actuation of Mo- and W-dichalcogenide monolayers

Vuong Van Thanh; Nguyen Tuan Hung; Do Van Truong

doi:10.1039/c8ra08248k

Charge-induced electromechanical actuation of Mo- and W-dichalcogenide monolayers

RSC Adv. 2018 Nov 16;8(67):38667-38672. doi: 10.1039/c8ra08248k. eCollection 2018 Nov 14.

Authors

Vuong Van Thanh¹, Nguyen Tuan Hung², Do Van Truong^{3

4}

Affiliations

¹ Department of Design of Machinery and Robot, School of Mechanical Engineering, Hanoi University of Science and Technology Hanoi Vietnam thanh.vuongvan@hust.edu.vn.
² Department of Physics, Tohoku University Sendai 980-8578 Japan nguyen@flex.phys.tohoku.ac.jp.
³ Department of Mechatronics, School of Mechanical Engineering, Hanoi University of Science and Technology Hanoi Vietnam.
⁴ International Institute for Computational Science and Engineering, Hanoi University of Science and Technology Hanoi Vietnam.

Abstract

Using first-principle density functional calculations, we investigate electromechanical properties of two-dimensional MX₂ (M = Mo, W; X = S, Se, Te) monolayers with the 1H and 1T structures as a function of charge doping for both electron and hole doping. We find that by increasing the atomic number, Z _X, of X atoms (Z _S < Z _Se < Z _Te), the work density per cycle of the MX₂ monolayers are increased and decreased for the 1H and 1T structures, respectively. On the other hand, the work density per cycle of the WX₂ monolayers are higher than that of the MoX₂ monolayers for both the 1H and 1T structures. Therefore, WTe₂ and WS₂ monolayers for the 1H and 1T structures, respectively, have the best electromechanical performances in the MX₂ compounds. In addition, the MX₂ monolayers show a reversible strain up to 3%, which is higher than that of graphene (∼1%). Our results provide an important insight into the electromechanical properties of the MX₂ monolayers, which are useful for artificial muscles applications.