# Local Anodic Oxidation of Graphene: The Role of Number of Layers, Load Force, and Substrate

## TL;DR

This paper explores how factors like graphene layers, load force, and substrate adhesion affect the oxidation of graphene, showing that specific conditions are needed for successful oxidation.

## Contribution

The study identifies new conditions for successful graphene oxidation using local anodic oxidation, emphasizing the role of load force and adhesion.

## Key findings

- Oxidation of graphene occurs only with low pulling force and strong adhesion to the substrate.
- Failure to meet these conditions can lead to non-oxide structures like graphene removal or cavity formation.
- Water meniscus stability is crucial for reproducible oxidation.

## Abstract

Local anodic oxidation
has become a convenient technique
for fabricating
graphene oxide nanostructures in fundamental research (e.g., nanoelectronics).
The process is typically controlled by tip–sample voltage,
scanning speed, relative humidity, and tip characteristics (e.g.,
tip radius). The role of other parameters, such as the number of layers,
load force, and graphene-substrate adhesion, is discussed in this
paper. It is shown by atomic force microscopy, Kelvin probe force
microscopy, and Raman spectroscopy that the oxidation of graphene
is achievable only under specific conditions: low pulling force and
sufficiently strong adhesion of graphene to its substrate. Such conditions
ensure the stability of graphene on the surface and the proper formation
of the water meniscus, which serves as a source of oxidizing ions,
resulting in a reproducible oxidation process. Failure to comply with
these conditions may lead to the formation of structures other than
oxides (e.g., removal of graphene or the formation of air/water cavities
under graphene), which is also demonstrated.