Atomistic mechanism of stress modulated phase transition in monolayer MoTe2

Monolayer MoTe2, one of the 2D transition metal dichalcogenide (TMD) materials, exhibits two stable structural phases: semiconducting 2H phase and metallic 1T phase. The dynamic control of the transition between these two phases on a single atomically thin sheet holds promise for a variety of revolutionary device applications. Particularity, stress could be utilized to dynamically modulate such phase transition. To date, the atomistic and kinetic mechanism of the phase transition under stress is not clear. In this paper, the finite deformation nudged elastic band method and density functional theory are applied to determine the phase transition barriers and pathways of monolayer MoTe2 as a function of applied stress. It is found that the stress can greatly influence the thermodynamics and kinetics of the phase nucleation and propagation. The results shed light on the phase engineering of 2D TMD materials with stress at the atomic level. (C) 2020 Elsevier Ltd. All rights reserved.