Interaction between graphene and SiO2 surface

TL;DR

This study uses first-principles DFT calculations to analyze how graphene interacts with SiO2 surfaces, revealing stable configurations and the hole-doping mechanism caused by oxygen defects.

Contribution

It provides a detailed theoretical analysis of graphene-SiO2 interactions, including the effects of surface defects on electronic properties.

Findings

Graphene remains stably on SiO2 surfaces in various configurations.

Oxygen defects in SiO2 shift graphene's Fermi level downward.

The study explains the experimentally observed hole-doping effect of graphene on SiO2.

Abstract

With first-principles DFT calculations, the interaction between graphene and SiO2 surface has been analyzed by constructing the different configurations based on {\alpha}-quartz and cristobalite structures. The single layer graphene can stay stably on SiO2 surface is explained based on the general consideration of configuration structures of SiO2 surface. It is also found that the oxygen defect in SiO2 surface can shift the Fermi level of graphene down which opens out the mechanism of hole-doping effect of graphene absorbed on SiO2 surface observed in experiments.