Abstract
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.
Highlights
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
A band gap may be opened by charge transfer doping from either adsorbed molecules or a substrate to open a tunable gap of 50–100 meV, as shown by Park et al where bilayer graphene was used in single gate n-type FETs1
This study reports the use of graphene modified with cobalt to induce an electronic band gap in a manner that is scalable and low in complexity
Summary
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. Several studies have resulted in successful methods to open a band gap in graphene These include the use of multilayer graphene functionalized with organic molecules in order to break the layer symmetry[7,8,9,10], heterogeneous or single atom substitutions[11,12], quantum confinement using graphene nano-ribbons[13,14], and oxygen functionalization related to graphene oxide (GO)[15,16,17,18,19,20]. At a cobalt thickness of 0.12 nm on graphene/SiO2 a band gap forms at room temperature due to formation of both oxygen functional groups on the graphene and CoO
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
