Insights and Implications of Intricate Surface Charge Transfer and sp3-Defects in Graphene/Metal Oxide InterfacesShow others and affiliations
2022 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 14, no 31, p. 36209-36216Article in journal (Refereed) Published
Abstract [en]
Adherence of metal oxides to graphene is of fundamental significance to graphene nanoelectronic and spintronic interfaces. Titanium oxide and aluminum oxide are two widely used tunnel barriers in such devices, which offer optimum interface resistance and distinct interface conditions that govern transport parameters and device performance. Here, we reveal a fundamental difference in how these metal oxides interface with graphene through electrical transport measurements and Raman and photoelectron spectroscopies, combined with ab initio electronic structure calculations of such interfaces. While both oxide layers cause surface charge transfer induced p-type doping in graphene, in sharp contrast to TiOx, the AlOx/graphene interface shows the presence of appreciable sp3 defects. Electronic structure calculations disclose that significant p-type doping occurs due to a combination of sp3 bonds formed between C and O atoms at the interface and possible slightly off-stoichiometric defects of the aluminum oxide layer. Furthermore, the sp3 hybridization at the AlOx/graphene interface leads to distinct magnetic moments of unsaturated bonds, which not only explicates the widely observed low spin-lifetimes in AlOx barrier graphene spintronic devices but also suggests possibilities for new hybrid resistive switching and spin valves.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2022. Vol. 14, no 31, p. 36209-36216
Keywords [en]
Charge transfer, graphene, graphene electronics, sp3-defects, spintronics
National Category
Condensed Matter Physics
Identifiers
URN: urn:nbn:se:oru:diva-100629DOI: 10.1021/acsami.2c06626ISI: 000886012300001PubMedID: 35867345Scopus ID: 2-s2.0-85135768957OAI: oai:DiVA.org:oru-100629DiVA, id: diva2:1687488
Funder
European CommissionSwedish Research Council, 2016-03278 02017-05030 2019-03666 2019-03569 2021-03675 200-0602Swedish Energy Agency, 48698-1Swedish Research Council Formas, 2019-01326Wenner-Gren Foundations, UPD2018-0003 UPD2019-0166
Note
Funding agency:
Göran Gustafsson Foundation 2132
2022-08-152022-08-152022-12-02Bibliographically approved