Correlation between morphology and transport properties of quasi-free-standing monolayer graphene

TL;DR

This study explores how the surface morphology of quasi-free-standing monolayer graphene, created at different temperatures, affects its electrical transport properties, highlighting the impact of structural features on carrier mobility.

Contribution

It provides new insights into the correlation between specific morphological features and transport behavior in QFMLG formed at various temperatures.

Findings

Incomplete hydrogen intercalation introduces charged impurity scattering.

Higher formation temperatures lead to substrate voids and wrinkling, reducing mobility.

Morphological features directly influence the electronic transport properties.

Abstract

We investigate the morphology of quasi-free-standing monolayer graphene (QFMLG) formed at several temperatures by hydrogen intercalation and discuss its relationship with transport properties. Features corresponding to incomplete hydrogen intercalation at the graphene-substrate interface are observed by scanning tunneling microscopy on QFMLG formed at 600 and 800{\deg}C. They contribute to carrier scattering as charged impurities. Voids in the SiC substrate and wrinkling of graphene appear at 1000{\deg}C, and they decrease the carrier mobility significantly.