Combined effect of edge roughness and phonon scattering on the electronic properties of ultra scaled graphene nano-ribbons

• Combined effect of phonon and edge-roughness scattering in scaled graphene nanoribbons is simulated using NEGF.
• Effect of these phenomena on transmission, conductance, and transport gap have been evaluated.
• Our results show edge roughness slightly reduces onset of optical phonon emission.
• Acoustic phonons reduce off-state and optical phonons reduce on-state conductance in all roughness intensities.
• In longer ribbons with high edge roughness, phonons increase the transport gap.

The effect of optical and acoustic phonon-scattering in the presence of line-edge-roughness (LER) on the electronic properties of ultra-scaled armchair graphene nano-ribbons (AGNRs) is investigated. Non-equilibrium Green’s function formalism (NEGF) is employed using a Hamiltonian formed from tight bonding model with consideration of first and third nearest neighbors. The combined effect of phonons and line edge roughness on the transmission, transport gap, and conductance are studied for different roughness strengths and AGNR lengths. Results show edge roughness slightly reduces the onset of optical phonon emission, acoustic phonons reduce off-state conductance and optical phonons reduce on-state conductance. In both cases, the degree and behavior of reduction is totally dependent on the intensity of edge roughness. Also, in the longer AGNRs with high edge roughness intensity, phonons increase the transport gap.