Investigation of Interfacial Charge Transfer in M⁺/graphene system

Interactions and charge transfer between graphene and engineered environment have a critical role in the electronic and optical properties of graphene due to the potential to locally dope or modify the graphene band structure. Metal adatoms on graphene have drawn great attention because of their ability to affect structural/ electronic properties either by creating defects on the graphene lattice or opening a band gap. Incorporating metal atoms such as Hg into single or few-layer graphene is a promising candidate for inducing diverse unique optoelectronic devices. Confocal Raman spectroscopy and X-Ray Photoelectron Spectroscopy (XPS) measurements were used to study doping, strain configuration, and chemical modification of graphene. In addition, Kelvin probe force microscopy (KPFM) was used to investigate the contact potential difference (CPD) and local charge-related phenomena on M+ decorated graphene. Charge mobility was measured by conductive force microscopy (c-AFM). Finally, we speculate two phenomena by stabilizing metal atoms on graphene. First, tunning Fermi level due to charge transfer between M⁺ and graphene which is induced by lattice defects graphene. And second, opening a band gap by creating a new topological state induced by spin-orbit coupling (SOC).