Exploring the effect of varying regime of ion fluence on optical and surface electronic properties of CVD Grown Graphene

TL;DR

This study investigates how varying ion fluence during swift heavy ion irradiation modifies the defect structure, optical, and electronic surface properties of CVD-grown graphene, revealing a pathway for controlled property tuning.

Contribution

It introduces a detailed analysis of ion fluence effects on defect formation and property modulation in graphene, highlighting the transition from doping to amorphization with increasing ion dose.

Findings

Low ion dose induces acceptor doping via vacancy creation.

High ion dose causes dense electronic excitation leading to amorphous carbon formation.

Ion fluence controls the transition from crystalline to amorphous graphene.

Abstract

In this work, the effect of the ion fluence-dependent defect formation on the modification of surface electronic and optical properties of graphene has been investigated. The chemical vapor deposited (CVD) graphene was irradiated with swift heavy ion (SHI) (70 MeV Si+5) beam at different fluence to study the defect formation mechanism and the role of it in modulating its surface electronic property such as work function. At low ion dose, acceptor doping via vacancy creation was observed; whereas dense electronic excitation dominated extended defects was realized at higher dose, which subsequently transforms the crystalline graphene into amorphous carbon. The results from UV-Vis spectroscopy, Raman spectroscopy and scanning Kelvin probe microscopy (SKPM) support the fact. Thus a new pathway of transformation of graphene under SHI irradiation was explored where ion dose could be the main factor to realize several effects in graphene.