Evolution of graphene nanoribbons under low-voltage electron irradiation
Permanent link to this recordhttp://hdl.handle.net/10754/598260
MetadataShow full item record
AbstractThough the all-semiconducting nature of ultrathin graphene nanoribbons (GNRs) has been demonstrated in field-effect transistors operated at room temperature with ∼10<sup>5</sup> on-off current ratios, the borderline for the potential of GNRs is still untouched. There remains a great challenge in fabricating even thinner GNRs with precise width, known edge configurations and specified crystallographic orientations. Unparalleled to other methods, low-voltage electron irradiation leads to a continuous reduction in width to a sub-nanometer range until the occurrence of structural instability. The underlying mechanisms have been investigated by the molecular dynamics method herein, combined with in situ aberration-corrected transmission electron microscopy and density functional theory calculations. The structural evolution reveals that the zigzag edges are dynamically more stable than the chiral ones. Preferential bond breaking induces atomic rings and dangling bonds as the initial defects. The defects grow, combine and reconstruct to complex edge structures. Dynamic recovery is enhanced by thermal activation, especially in cooperation with electron irradiation. Roughness develops under irradiation and reaches a plateau less than 1 nm for all edge configurations after longtime exposure. These features render low-voltage electron irradiation an attractive technique in the fabrication of ultrathin GNRs for exploring the ultimate electronic properties. © 2012 The Royal Society of Chemistry.
CitationZhu W, Wang H, Yang W (2012) Evolution of graphene nanoribbons under low-voltage electron irradiation. Nanoscale 4: 4555. Available: http://dx.doi.org/10.1039/c2nr30648d.
SponsorsWe acknowledge the Advanced Nanofabrication, Imaging and Characterization Core Lab in King Abdullah University of Science and Technology for characterization facilities. This work has been supported by the National Science Foundation of China and Science Foundation of Chinese University (Grant no. 2011QNA4038). The computational work carried out by TianHe-1(A) system at the National Supercomputer Center in Tianjin, China is gratefully acknowledged.
PublisherRoyal Society of Chemistry (RSC)