Strain,
as an economic yet controllable approach for structural
modulation, frequently plays a vital role in the preparation and performance
optimization of two-dimensional nanomaterials (TNMs). Here, utilizing
first-principles simulations, the analysis of energetics shows that
the biaxial stretching and compressing could facilitate the vertical
separation and horizontal sliding in graphene (Gr/Gr), hexagonal boron
nitride (h-BN/h-BN), and molybdenum
disulfide (MoS2/MoS2) bilayers. The quantification
of electron redistribution between layers confirmed that the shifts
of interlayer charge density (ρinter–) and
its relative values (Δρ
inter–) are responsible for the vertical separation and horizontal sliding
facilitated by biaxial strain. More effortless horizontal sliding
was enabled by a smoother potential energy surface because a smaller Δρ
inter– can be acquired under
compression, whereas more effortless vertical separation followed
a more vulnerable surface energy because a lower ρinter– occurs under tensile strain. The vertical and horizontal division
of strain effect provides a novel idea for further understanding its
pivotal roles in strain engineering of commensurate-contact TNMs,
such as mechanical exfoliation and solid lubrication.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.