81 research outputs found
Visualizing Individual Nitrogen Dopants in Monolayer Graphene
In monolayer graphene, substitutional doping during growth can be used to
alter its electronic properties. We used scanning tunneling microscopy (STM),
Raman spectroscopy, x-ray spectroscopy, and first principles calculations to
characterize individual nitrogen dopants in monolayer graphene grown on a
copper substrate. Individual nitrogen atoms were incorporated as graphitic
dopants, and a fraction of the extra electron on each nitrogen atom was
delocalized into the graphene lattice. The electronic structure of
nitrogen-doped graphene was strongly modified only within a few lattice
spacings of the site of the nitrogen dopant. These findings show that chemical
doping is a promising route to achieving high-quality graphene films with a
large carrier concentration.Comment: Science 201
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