Strain-mediated phase transition of MoTe2 monolayer

Abstract

MoTe2 has emerged as a promising candidate in the field of integrated circuits, memristive devices, and catalysts, owing to its polymorphic nature across different phases. Experimentally, strain engineering has been demonstrated as an effective approach for manipulating the phase transition of MoTe2, but the mechanism remains unclear. The strain-dependent phase transition and its micro-mechanisms have been investigated based on first principle calculations. As demonstrated, critical strain and phase transition path from H → T′ phases are strongly governed by the applied strain's orientation, magnitude, and triaxiality. At the atomic level, nonzero movements of Te atoms within the phase transition domain with mechanical unloading have been clarified, together with an advanced understanding on the impact of strain on Te-vacancies migration. These insights advanced the knowledge of MoTe2 phase transition behavior and demonstrated the large space to explore potential applications through strain, defect, and phase engineering.