Characterization of electronic structure of periodically strained graphene

Journal Article · Mon Nov 02 04:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4934701· OSTI ID:22486019

Aslani, Marjan; Nishi, Yoshio ^[1]; Kumar, Suhas ^[1]; Nordlund, Dennis ^[2]; Pianetta, Piero ^[1]

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1. Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)
2. Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States)

We induced periodic biaxial tensile strain in polycrystalline graphene by wrapping it over a substrate with repeating pillar-like structures with a periodicity of 600 nm. Using Raman spectroscopy, we determined to have introduced biaxial strains in graphene in the range of 0.4% to 0.7%. Its band structure was characterized using photoemission from valance bands, shifts in the secondary electron emission, and x-ray absorption from the carbon 1s levels to the unoccupied graphene conduction bands. It was observed that relative to unstrained graphene, strained graphene had a higher work function and higher density of states in the valence and conduction bands. We measured the conductivity of the strained and unstrained graphene in response to a gate voltage and correlated the changes in their behavior to the changes in the electronic structure. From these sets of data, we propose a simple band diagram representing graphene with periodic biaxial strain.

• OSTI ID: 22486019
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 18 Vol. 107; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
DENSITY OF STATES
ELECTRIC POTENTIAL
ELECTRON EMISSION
ELECTRONIC STRUCTURE
GRAPHENE
PERIODICITY
PHOTOEMISSION
POLYCRYSTALS
RAMAN SPECTROSCOPY
STRAINS
SUBSTRATES
VALENCE
WORK FUNCTIONS
X RADIATION