  Delamination of thin films from the supportive substrates is critical issues
in thin film industry and technology. The emergent two-dimensional materials,
atomic layered materials, such as transition metal dichalcogenides are highly
flexible thus the buckles and wrinkles can be easily generated and play vital
effects on the physical properties. Here we introduce one kind of patterned
buckling behavior caused by the delamination from substrate initiated at the
edges of the chemical vapor deposition synthesized monolayer transition metal
dichalcogenides, mainly due to the thermal expansion mismatch. The atomic force
microscopy and optical characterizations clearly showed the puckered structures
associated with strains, whereas the transmission electron microscopy revealed
the special sawtooth shaped edge structures which break the geometrical
symmetry of the buckling behavior of hexagonal samples. The condition of this
edge delamination is in accordance with the fracture theory. This edge
delamination process and buckling upon synthesis is universal for most of the
ultrathin two dimensional materials, and it is definitely noteworthy in their
future applications.
