  Nonlinear electrical properties, such as negative differential resistance
(NDR), are essential in numerous electrical circuits, including memristors.
Several physical origins have been proposed to lead to the NDR phenomena in
semiconductor devices in the last more than half a century. Here, we report NDR
behavior formation in randomly oriented graphene-like nanostructures up to 37 K
and high on-current density up to 10^5 A/cm^2. Our modeling of the
current-voltage characteristics, including the self-heating effects, suggests
that strong temperature dependence of the low-bias resistance is responsible
for the nonlinear electrical behavior. Our findings open opportunities for the
practical realization of the on-demand NDR behavior in novel class of 2D and 3D
material-based devices via heat management in the conducting films and the
underlying substrates.
