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Title: Characterization of electronic structure of periodically strained graphene

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.
Authors:
; ;  [1] ;  [1] ;  [2] ;  [3] ;  [1] ;  [2]
  1. Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)
  2. (United States)
  3. Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States)
Publication Date:
OSTI Identifier:
22486019
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 18; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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