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arXiv · 2208.07080

sp$^{2}$/sp$^{3}$ bonding controlling mechanism at the $\alpha$-Al$_{2}$O$_{3}|$graphene interface

Renan P. Maciel·Chin Shen Ong·Daria Belotcerkovtceva·Yaroslav O. Kvashnin·Danny Thonig·M. Venkata Kamalakar·Olle Eriksson
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Abstract

First-principles calculations reported here illuminate the effects of the interfacial properties of $\alpha$-Al$_{2}$O$_{3}$ and graphene, with emphasis on the structural and electronic properties. Various contact interfaces and different $\alpha$-Al$_{2}$O$_{3}$ surface terminations are considered with on and slightly-off stoichiometric aluminium oxide. We show that depending on whether aluminium or oxygen is in contact with graphene, an $sp^{3}$ structural deformation and spontaneous spin-polarization may occur next to the interface contact. Interestingly, some cases cause a $p$-type doping in the graphene band structure, depending on the initial $\alpha$-Al$_{2}$O$_{3}$ geometry placed on graphene. The importance of leaving the surface dangling bonds of alumina saturated or not is also highlighted, and we show that it might be a control mechanism for opening a gap in graphene by the influence of the $sp^{3}$ bond between oxygen and carbon atoms at the interface. We discuss the potential of utilizing this sensitivity for practical applications.

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Renan P. Maciel, Chin Shen Ong, Daria Belotcerkovtceva, Yaroslav O. Kvashnin, Danny Thonig, M. Venkata Kamalakar, Olle Eriksson. 2022-08-15. sp$^{2}$/sp$^{3}$ bonding controlling mechanism at the $\alpha$-Al$_{2}$O$_{3}|$graphene interface. https://arxiv.org/abs/2208.07080

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