Giant Quasiparticle Bandgap Modulation in Graphene Nanoribbons Supported on Weakly Interacting Surfaces

Xueping Jiang, Rensselaer Polytechnic Institute
Neerav Kharche, Rensselaer Polytechnic Institute
Paul Kohl, Georgia Institute of Technology - Main Campus
Timothy B. Boykin, University of Alabama - Huntsville
Gerhard Klimeck, Network for Computational Nanotechnology, Purdue University
Mathieu Luisier, Integrated Systems Laboratory, Zurich, Switzerland
Pulickel M. Ajayan, Rice University
Saroj K. Nayak, Indian Institute of Technology Bhubaneswar, India

Abstract

In general, there are two major factors affecting bandgaps in nanostructures: (i) the enhanced electron-electron interactions due to confinement and (ii) the modified selfenergy of electrons due to the dielectric screening. While recent theoretical studies on graphene nanoribbons (GNRs) report on the first effect, the effect of dielectric screening from the surrounding materials such as substrates has not been thoroughly investigated. Using large-scale electronic structure calculations based on the GW approach, we show that when GNRs are deposited on substrates, bandgaps get strongly suppressed (by as much as 1 eV) even though the GNR-substrate interaction is weak.

Discipline(s)

Nanoscience and Nanotechnology