  Formation of wrinkles is a common phenomenon in the large area growth of two
dimensional layered materials on metallic substrates. Wrinkles can
significantly affect the working of 2D materials based large scale electronic
devices and therefore, it is of utmost importance to investigate local
electrical properties of such wrinkled/folded structures on 2D materials. Here,
we report local conductivity measurements by conducting atomic force microscopy
(CAFM) and surface potential mapping by Kelvin Probe Force microscopy (KPFM) on
large area wrinkled turbostratic graphene films grown on nickel foils. We show
that the electrical transport current is several orders of magnitude higher on
the wrinkles than that on the flat regions of the graphene films. Therefore,
our results suggest that controlled engineering of such wrinkles on graphene
may facilitate development of superior graphene-based nano-electronic devices
where transport of high current through narrow channels are desired.
