Influence of ageing on Raman spectra and the conductivity of monolayer graphene samples irradiated by heavy and light ions

TL;DR

This study investigates how long-term ageing affects the Raman spectra and conductivity of monolayer graphene irradiated with ions, revealing changes in spectral features and increased conductivity linked to defect-related structural modifications.

Contribution

It provides new insights into the effects of ageing on irradiated graphene's spectral and electrical properties, highlighting defect-related structural changes over time.

Findings

Changes in D-, G-, and 2D-line intensities and positions in RS spectra

Increase in electrical conductivity after ageing

Defect area expansion around structural defects

Abstract

The influence of long-term ageing (about one year) on the Raman scattering (RS) spectra and the temperature dependence of conductivity has been studied in two series of monolayer graphene samples irradiated by different doses of C$^{+}$ and Xe$^{+}$ ions. It is shown that the main result of ageing consists of changes in the intensity and position of D- and G- and 2D-lines in RS spectra and in an increase of the conductivity. The observed effects are explained in terms of an increase of the radius of the \textquotedblleft activated\textquotedblright{} area around structural defects.