Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 34: Poster Session I (Graphene; Plasmonics and nanooptics; Coherence and coherent control in nanophotonics and plasmonics)

O 34.9: Poster

Dienstag, 27. März 2012, 18:15–21:45, Poster E

Strain Modulation of Graphene Nanoribbons — •Yingchun Cheng¹, Hongtao Wang², Zhiyong Zhu¹, Xixiang Zhang³, and Udo Schwingenschlogl¹ — ¹PSE Division, KAUST, Thuwal 23955-6900, Kingdom of Saudi Arabia — ²Institute of Applied Mechanics, Zhejiang University, Hangzhou 310027, China — ³Advanced Nanofabrication, Imaging and Characterization Core Lab, KAUST, Thuwal 23955-6900, Kingdom of Saudi Arabia

The edge structure and width of graphene nanoribbons (GNRs) are crucial factors determining the electronic structure. A combination of experiment and first-principles calculations allows us to study the mechanism of transformation from hexagon-hexagon (66) to pentagon-heptagon (57) configuration. Thin GNRs (<2 nm) are fabricated by bombardment of a graphene sheet with high-energetic Au clusters. The edges of the GNRs are modified in-situ by electron irradiation. Tensile strain along the edge decreases the transformation energy barrier from the 66 to the 57-GNR. A thin 66-GNR is antiferromagnetic with direct band gap, a 57-GNR turns out to be an indirect semiconductor, and a GNR transformed on only one edge is ferromagnetic. We propose that strain can be an effective method to tune the edge (and electronic) structure of thin GNRs for graphene based electronics.