Selective Area Band Engineering of Graphene using Cobalt-Mediated Oxidation.
This study reports a scalable and economical method to open a band gap in single layer graphene by deposition of cobalt metal on its surface using physical vapor deposition in high vacuum. At low cobalt thickness, clusters form at impurity sites on the graphene without etching or damaging the graphene. When exposed to oxygen at room temperature, oxygen functional groups form in proportion to the cobalt thickness that modify the graphene band structure. Cobalt/Graphene resulting from this treatment can support a band gap of 0.30 eV, while remaining largely undamaged to preserve its structural and electrical properties. A mechanism of cobalt-mediated band opening is proposed as a two-step process starting with charge transfer from metal to graphene, followed by formation of oxides where cobalt has been deposited. Contributions from the formation of both CoO and oxygen functional groups on graphene affect the electronic structure to open a band gap. This study demonstrates that cobalt-mediated oxidation is a viable method to introduce a band gap into graphene at room temperature that could be applicable in electronics applications.
Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada.
Paul F
PF
Bazylewski
Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon 440-746, Korea.
Van Luan
VL
Nguyen
Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada.
Robert P C
RP
Bauer
Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada.
Adrian H
AH
Hunt
Institute Materials Chemistry, Vienna University of Technology, Getreidemarkt 9/165-TC, A-1060 Vienna, Austria.
Eamon J G
EJ
McDermott
Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada.
Brett D
BD
Leedahl
Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620990 Yekaterinburg, Russia.|Ural Federal University, 19 Mira Str., 620002 Yekaterinburg, Russia.
Andrey I
AI
Kukharenko
Ural Federal University, 19 Mira Str., 620002 Yekaterinburg, Russia.
Seif O
SO
Cholakh
Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620990 Yekaterinburg, Russia.|Ural Federal University, 19 Mira Str., 620002 Yekaterinburg, Russia.
Ernst Z
EZ
Kurmaev
Institute Materials Chemistry, Vienna University of Technology, Getreidemarkt 9/165-TC, A-1060 Vienna, Austria.
Peter
P
Blaha
Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada.
Alexander
A
Moewes
Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon 440-746, Korea.|Department of Physics and Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Korea.
Young Hee
YH
Lee
Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada.
Gap Soo
GS
Chang
D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D013499:Surface Properties
D010087:Oxides; D003035:Cobalt; D006108:Graphite; D010100:Oxygen; C060728:cobalt oxide