On resonant scatterers as a factor limiting carrier mobility in graphene

TL;DR

This paper investigates how atomic-scale defects, acting as resonant scatterers, limit the electron mobility in substrate-supported graphene, using Raman spectroscopy and hydrogen adsorbates to model impurity effects.

Contribution

It identifies atomic-scale defects as key factors in limiting graphene's mobility and demonstrates their impact through experimental modeling with hydrogen adsorbates.

Findings

Atomic defects cause a D peak in Raman spectra.

Resonant scatterers limit graphene mobility.

Hydrogen adsorbates mimic substrate impurities.

Abstract

We show that graphene deposited on a substrate has a non-negligible density of atomic scale defects. This is evidenced by a previously unnoticed D peak in the Raman spectra with intensity of about 1% with respect to the G peak. We evaluated the effect of such impurities on electron transport by mimicking them with hydrogen adsorbates and measuring the induced changes in both mobility and Raman intensity. If the intervalley scatterers responsible for the D peak are monovalent, their concentration is sufficient to account for the limited mobilities achievable in graphene on a substrate.