  Due to the distinguished properties offered by different structural phases of
monolayer MoS2, phase engineering design are urgently required for achieving
switchable structural phase. Strain engineering is widely accepted as a clean
and flexible method, however, cannot be achieved in engineering monolayer MoS2
phase transition because the critical biaxial strain required (~15%) is much
larger than measured elastic limit (~11%). In this study, employing density
functional theoretical calculations, it has been found out that with the
forming of heterostructure between MoS2 with buckled 2D materials such as
silicence, germanene and stanene, only a small strain can trigger the phase
transition. As being suggested by the constructed phase stability diagram,
biaxial deformation as low as 3% in MoS2/silicene and MoS2/stanene sandwich
structure, would be sufficient to induce the structural phase transition in
MoS2 lattice. This strain falls well within experimental elastic limit, thus
would be feasible to realize in experiment. The origin of such behavior can be
understood as strain induced interlayer covalent bond formation, which finally
make MoS2 lattice more sensitive to external strain. This theoretical work
provides one realistic route for achieving flexible phase stabilities in
experimental design.
