  Two-dimensional (2D) crystals, such as graphene, hexagonal boron nitride and
transitional metal dichalcogenides, have attracted tremendous amount of
attention over the past decade due to their extraordinary thermal, electrical
and optical properties, making them promising nano-materials for the
next-generation electronic systems. A large number of heterostructures have
been fabricated by stacking of various 2D materials to achieve different
functionalities. In this work, we simulate the electron transport properties of
a three-terminal multilayer heterostructure made from graphene nanoribbons
vertically sandwiching a boron nitride tunneling barrier. To investigate the
effects of the unavoidable misalignment in experiments, we introduce a tunable
angular misorientation between 2D layers to the modeled system. Current-Voltage
(I-V) characteristics of the device exhibit multiple NDR peaks originating from
distinct mechanisms. A unique NDR mechanism arising from the lattice mismatch
is captured and it depends on both the twisting angle and voltage bias.
Analytical expressions for the positions of the resonant peaks observed in I-V
characteristic are developed. To capture the slight degradation of PVR ratios
observed in experiments when temperature increases from 2K to 300K,
electron-photon scattering decoherence has been added to the simulation,
indicating a good agreement with experiment works as well as a robust
preservation of resonant tunneling feature.
