Indian Journal of Science and Technology

Abstract

Objectives: In this work, we probe the effect of ambient conditions on few layer and multi-layer graphene interfaces in Si and SiO2 /Si substrates. Methods/Statistical Analysis: Scanning probe microscopy techniques have been employed to study the topography of the few layer graphene and multi-layer graphene interfaces by Intermittent-Contact Atomic Force Microscopy (IC-AFM) and the changes in the surface gradient of electrical forces have been probed by electrical force microscopy. A study of different thickness of mechanically exfoliated graphene layers, with and without folds, deposited on SiO2 /Si and Si substrates is presented here. Findings: The number of ambient ice-like water ad-layers are determined by measurement of the heights of the graphene layers using IC-AFM, while as Electrical Force Microscopy (EFM) is used to determine the nature of the electrical interaction forces at the graphene interfaces on the different substrates. It is found that with increasing thickness of graphene on Si substrates, the electrostatic interaction increases on account of larger number of ambient ice-like water ad-layers formed. Application/Improvements: The electrical nature of Graphene interfaces on hydrophilic and hydrophobic substrates have an important role for the graphene-based devices operating under ambient.
Keywords: Ambient Ice-like Water ad-Layers (IWLs), Atomic Force Microscopy (AFM), Graphene, Interfaces