Switching Behavior of Carbon Chains Bridging Graphene Nanoribbons: Effects of Uniaxial Strain

• Published in: ACS nano 2011-03, Vol.5 (3), p.1769-1774
• Main Authors: Akdim, Brahim, Pachter, Ruth
• Format: Article
• Language: English
• Subjects: Computer Simulation; Elastic Modulus; Electric Conductivity; Macromolecular Substances - chemistry; Models, Chemical; Models, Molecular; Molecular Conformation; Nanotubes, Carbon - chemistry; Nanotubes, Carbon - ultrastructure; Particle Size; Signal Processing, Computer-Assisted; Stress, Mechanical; Surface Properties; Tensile Strength
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/nn102403j

Recently, several experiments demonstrated the stability of chain-like carbon nanowires bridged between graphene nanoribbons, paving the way for potential applications in nanodevices. On the basis of density functional tight-binding calculations, we demonstrated switching for chains terminated with a five-membered ring under an applied strain, serving as a model for morphological changes in realistic materials. Electron transport calculations showed an increase of up to 100% in the output current, achieved at a reverse bias voltage of −2 V and an applied strain of just 1.5%. Structural analysis suggested that the switching is driven by conformational changes, where in our case is triggered by the formation and annihilation of a five-membered ring at the interface of the chain−graphene edge. In addition, we showed that a five-membered ring can easily be formed at the interface under a source−drain bias or through a gate voltage. This mechanism can serve as an explanation of experimentally observed conductance for the materials.