Presentation Information
[8p-PB3-20]Numerical Analysis of Resonant Tunneling Transport in Graphene Nanoribbons with Double h-BN Barriers
〇Shoichi Sakamoto1 (1.Seikei Univ.)
Keywords:
Graphene Nanoribbon,Resonant Tunneling Transport,h-BN Heterostructure
We numerically investigate the resonant tunneling transport properties of graphene nanoribbons (GNRs) containing double hexagonal boron nitride (h-BN) barriers. The electronic structures were calculated using density functional theory (DFT), and the transport properties were evaluated by the non-equilibrium Green's function (NEGF) method implemented in the SIESTA package.
The model consists of an armchair graphene nanoribbon in which two h-BN barriers are embedded, forming a quantum-well-like region between the barriers. The transmission spectra exhibit sharp resonant peaks around the Fermi energy. The spacing between these resonant levels depends strongly on the barrier separation, indicating that the electronic states are governed by quantum confinement within the well region.
The calculated current-voltage characteristics show distinct threshold voltages and plateau regions. These features originate from resonant tunneling through discrete electronic states confined between the h-BN barriers. Analysis of the partial density of states reveals that, under resonant conditions, localized states in the quantum well couple efficiently with the electrode states, resulting in enhanced electron transmission.
In addition, the effect of an external gate electric field was examined using an ideal planar gate electrode model. The gate field shifts the resonant transmission peaks and modifies the current near the threshold voltage. These results suggest that the transport properties of the double-barrier structure can be controlled not only by the barrier geometry but also by gate-induced electrostatic modulation. The present study provides fundamental insight into resonant tunneling phenomena in graphene-based nanostructures and demonstrates their potential application to future graphene electronic and field-effect transistor devices.
The model consists of an armchair graphene nanoribbon in which two h-BN barriers are embedded, forming a quantum-well-like region between the barriers. The transmission spectra exhibit sharp resonant peaks around the Fermi energy. The spacing between these resonant levels depends strongly on the barrier separation, indicating that the electronic states are governed by quantum confinement within the well region.
The calculated current-voltage characteristics show distinct threshold voltages and plateau regions. These features originate from resonant tunneling through discrete electronic states confined between the h-BN barriers. Analysis of the partial density of states reveals that, under resonant conditions, localized states in the quantum well couple efficiently with the electrode states, resulting in enhanced electron transmission.
In addition, the effect of an external gate electric field was examined using an ideal planar gate electrode model. The gate field shifts the resonant transmission peaks and modifies the current near the threshold voltage. These results suggest that the transport properties of the double-barrier structure can be controlled not only by the barrier geometry but also by gate-induced electrostatic modulation. The present study provides fundamental insight into resonant tunneling phenomena in graphene-based nanostructures and demonstrates their potential application to future graphene electronic and field-effect transistor devices.