# Hexagonal Boron Nitride Monolayers as Protective Barriers for Graphene during Thermal Annealing

## TL;DR

This study shows that h-BN protects graphene from damage during high-temperature cleaning processes.

## Contribution

The novel use of h-BN as a protective layer for graphene during thermal annealing is demonstrated.

## Key findings

- h-BN effectively protects graphene from damage at temperatures up to 500 °C.
- Thermal annealing in air is an effective method for removing PMMA residues.
- Raman and AFM confirm the protective role of h-BN on graphene.

## Abstract

In this study, we investigate the behavior of CVD-grown
monolayer
hexagonal boron nitride (h-BN) as a protective barrier on top of CVD-grown
monolayer graphene during the removal of poly­(methyl methacrylate)
(PMMA) residues by thermal annealing in air. We use a combination
of Raman spectroscopy, optical microscopy, and atomic force microscopy
to measure the damage of graphene and the efficacy of air annealing
as a cleaning method. Our experimental findings demonstrate the effectiveness
of h-BN as a protective barrier against graphene damage at temperatures
up to 500 °C compared with bare graphene.