Abstract
Scanning tunneling microscopy experiments have been performed to measure the local electron injection in nitrogen-doped graphene on and were successfully compared to ab initio calculations. In graphene, a gaplike feature is measured around the Fermi level due to a phonon-mediated tunneling channel. At nitrogen sites, this feature vanishes due to an increase of the elastic channel that is allowed because of symmetry breaking induced by the nitrogen atoms. A large conductance enhancement by a factor of up to 500 was measured at the Fermi level by comparing local spectroscopy at nitrogen sites and at carbon sites. Nitrogen doping can therefore be proposed as a way to improve tunnel-electron injection in graphene.
- Received 12 November 2014
- Revised 3 March 2015
DOI:https://doi.org/10.1103/PhysRevB.91.125442
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