N-Doping of Graphene Through Electrothermal Reactions with Ammonia
Xinran Wang,1
Xiaolin Li,1
Li Zhang,1
Youngki Yoon,2
Peter K. Weber,3
Hailiang Wang,1
Jing Guo,2
Hongjie Dai1,*
Graphene is readily p-doped by adsorbates, but for device applications,
it would be useful to access the n-doped material. Individual
graphene nanoribbons were covalently functionalized by nitrogen
species through high-power electrical joule heating in ammonia
gas, leading to n-type electronic doping consistent with theory.
The formation of the carbon-nitrogen bond should occur mostly
at the edges of graphene where chemical reactivity is high.
X-ray photoelectron spectroscopy and nanometer-scale secondary
ion mass spectroscopy confirm the carbon-nitrogen species in
graphene thermally annealed in ammonia. We fabricated an n-type
graphene field-effect transistor that operates at room temperature.
2 Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA.
3 Chemical Sciences Division, Lawrence Livermore National Laboratory (LLNL), Livermore, CA 94550, USA.
* To whom correspondence should be addressed. E-mail: hdai{at}stanford.edu
