  Transition metal dichalcogenide (TMD) monolayers attract great attention due
to their specific structural, electronic and mechanical properties. The
formation of their lateral heterostructures allows a new degree of flexibility
in engineering electronic and optoelectronic devices. However, the mechanical
properties of the lateral heterostructures are rarely investigated. In this
study, a comparative investigation on the mechanical characteristics of 1H, 1T'
and 1H/1T' heterostructure phases of different TMD monolayers including
molybdenum disulfide (MoS2) molybdenum diselenide (MoSe2), Tungsten disulfide
(WS2), and Tungsten diselenide (WSe2) was conducted by means of density
functional theory (DFT) calculations. Our results indicate that the lateral
heterostructures have a relatively weak mechanical strength for all the TMD
monolayers. The significant correlation between the mechanical properties of
the TMD monolayers and their structural phases can be used to tune their
stiffness of the materials. Our findings, therefore, suggest a novel strategy
to manipulate the mechanical characteristics of TMDs by engineering their
structural phases for their practical applications.
