Ultra-narrow metallic armchair graphene nanoribbons
نویسندگان
چکیده
Graphene nanoribbons (GNRs)-narrow stripes of graphene-have emerged as promising building blocks for nanoelectronic devices. Recent advances in bottom-up synthesis have allowed production of atomically well-defined armchair GNRs with different widths and doping. While all experimentally studied GNRs have exhibited wide bandgaps, theory predicts that every third armchair GNR (widths of N=3m+2, where m is an integer) should be nearly metallic with a very small bandgap. Here, we synthesize the narrowest possible GNR belonging to this family (five carbon atoms wide, N=5). We study the evolution of the electronic bandgap and orbital structure of GNR segments as a function of their length using low-temperature scanning tunnelling microscopy and density-functional theory calculations. Already GNRs with lengths of 5 nm reach almost metallic behaviour with ∼100 meV bandgap. Finally, we show that defects (kinks) in the GNRs do not strongly modify their electronic structure.
منابع مشابه
Symmetries and the conductance of graphene nanoribbons with long-range disorder
We study the conductance of graphene nanoribbons with long-range disorder. Due to the absence of intervalley scattering from the disorder potential, time-reversal symmetry (TRS) can be effectively broken even without a magnetic field, depending on the type of ribbon edge. Even though armchair edges generally mix valleys, we show that metallic armchair nanoribbons possess a hidden pseudovalley s...
متن کاملPerfect reflection of chiral fermions in gated graphene nanoribbons.
We describe the results of a theoretical study of transport through gated metallic graphene nanoribbons using a nonequilibrium Green function method. Although analogies with quantum field theory predict perfect transmission of chiral fermions through gated regions in one dimension, we find perfect reflection of chiral fermions in armchair ribbons for specific configurations of the gate. This ef...
متن کاملFull-band and atomistic study of electron-phonon interaction in graphene nanoribbons
Transmission function through metallic armchair-edge graphene nanoribbons is calculated within non-equilibrium Green’s function method including full-band electron–opticalphonon interaction. Structures appear in transmission function, which are originated in both zone-center and zone-edge optical-phonon scattering.
متن کاملEmergent properties and trends of a new class of carbon nanocomposites: graphene nanoribbons encapsulated in a carbon nanotube.
Using density functional theory calculations, we show that recently synthesized carbon nanocomposites of graphene nanoribbons encapsulated in a carbon nanotube (GNR@CNT) possess rich emergent electronic and magnetic properties that offer new functionality and tunability and display systematic trends that are sensitive to the matchup of constitutive GNRs and CNTs. The encapsulation of H-passivat...
متن کاملSpin-polarized transport through a zigzag-edge graphene flake embedded between two armchair nanoribbons electrodes
We study the coherent spin-polarized transport through a zigzag-edge graphene flake (ZGF), using Hubbard model in the nearest neighbor approximation within the framework of the Green function’s technique and Landauer formalism. The system considered consists of electrode/ (ZGF)/electrode, in which the electrodes are chosen to be armchair nanoribbons. The study was performed for two types of ele...
متن کامل