Density functional theory based study of graphene and dielectric oxide interfaces

Abstract

We study the effects of insulating oxides in their crystalline forms on the energy band structure of monolayer and bilayer graphene using a \textit{first principles} density functional theory based electronic structure method and a local density approximation. We consider the dielectric oxides, SiO${}_2$ ($\alpha$-quartz) and Al${}_2$O${}_3$ (alumina or $\alpha$-sapphire) each with two surface terminations. Our study suggests that atomic relaxations and resulting equilibrium separations play a critical role in perturbing the linear band structure of graphene in contrast to the less critical role played by dangling bonds that result from cleaving the crystal in a particular direction. We also see that with the addition of a second graphene layer, the Dirac cone is restored for the quartz surface terminations. Alumina needs more than two graphene layers to preserve the Dirac cone. Our results are at best semi-quantitative for the common amorphous forms of the oxides considered. However, crystalline oxides for which our results are quantitative provide an interesting option for graphene based electronics, particularly in light of recent experiments on graphene with crystalline dielectrics (hexagonal BN) that find considerable improvements in transport properties as compared to the those with amorphous dielectrics.

References in corpus (11)

• The Raman Fingerprint of Graphene
• Atomic Structure of Graphene on SiO2
• Realization of a High Mobility Dual-gated Graphene Field Effect Transistor with Al2O3 Dielectric
• Graphene films with large domain size by a two-step chemical vapor deposition process
• Intrinsic and extrinsic corrugation of monolayer graphene deposited on SiO2
• Graphene-on-Sapphire and Graphene-on-Glass: Raman Spectroscopy Study
• Spatially resolved spectroscopy of monolayer graphene on SiO2
• Morphology and flexibility of graphene and few-layer graphene on various substrates
• Spectro-microscopy of single and multi-layer graphene supported by a weakly interacting substrate
• Effective medium theory for disordered two-dimensional graphene
• Energy gap opening in submonolayer lithium on graphene: Local density functional and tight-binding calculations

Cited by in corpus (1)

• Density functional theory studies of interactions of graphene with its environment: substrate, gate dielectric and edge effects