Electronic Doping and Scattering by Transition Metals on Graphene

TL;DR

This study explores how transition metals deposited on graphene influence its electronic doping and scattering properties, revealing cluster formation, doping types, and deviations from Coulomb scattering, with implications for interface engineering.

Contribution

It provides experimental evidence of transition metal clusters causing n-type doping and distinct scattering behaviors, supporting theoretical predictions about interfacial dipoles.

Findings

TM clusters dope graphene n-type at room temperature

Scattering behavior differs from classical Coulomb scattering

Pt films can induce both n-type and weak p-type doping

Abstract

We investigate the effects of transition metals (TM) on the electronic doping and scattering in graphene using molecular beam epitaxy combined with in situ transport measurements. The room temperature deposition of TM onto graphene produces clusters that dope n-type for all TM investigated (Ti, Fe, Pt). We also find that the scattering by TM clusters exhibits different behavior compared to 1/r Coulomb scattering. At high coverage, Pt films are able to produce doping that is either n-type or weakly p-type, which provides experimental evidence for a strong interfacial dipole favoring n-type doping as predicted theoretically.