Direct graphene growth on Co3O4(111) by molecular beam epitaxy
2012 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 24, no 7, 072201- p.Article in journal (Refereed) Published
Direct growth of graphene on Co3O4(111) at 1000 K was achieved by molecular beam epitaxy from a graphite source. Auger spectroscopy shows a characteristic sp(2) carbon lineshape, at average carbon coverages from 0.4 to 3 ML. Low energy electron diffraction (LEED) indicates (111) ordering of the sp2 carbon film with a lattice constant of 2.5(+/-0.1) angstrom characteristic of graphene. Sixfold symmetry of the graphene diffraction spots is observed at 0.4, 1 and 3 ML. The LEED data also indicate an average domain size of similar to 1800 angstrom, and show an incommensurate interface with the Co3O4(111) substrate, where the latter exhibits a lattice constant of 2.8(+/-0.1) angstrom. Core level photoemission shows a characteristically asymmetric C(1s) feature, with the expected pi to pi* satellite feature, but with a binding energy for the 3 ML film of 284.9(+/-0.1) eV, indicative of substantial graphene-to-oxide charge transfer. Spectroscopic ellipsometry data demonstrate broad similarity with graphene samples physically transferred to SiO2 or grown on SiC substrates, but with the pi to pi* absorption blue-shifted, consistent with charge transfer to the substrate. The ability to grow graphene directly on magnetically and electrically polarizable substrates opens new opportunities for industrial scale development of charge- and spin-based devices.
Place, publisher, year, edition, pages
Institute of Physics , 2012. Vol. 24, no 7, 072201- p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-75721DOI: 10.1088/0953-8984/24/7/072201ISI: 000300390500001OAI: oai:DiVA.org:liu-75721DiVA: diva2:508770
Funding Agencies|Semiconductor Research Corporation, Division of Nanomanufacturing Sciences|2123.001|National Science Foundation|DMR-0907475MRI DMR-0922937|2012-03-092012-03-092012-03-21