Temperature dependence of the conductivity of graphene on boron nitride

TL;DR

This study compares how temperature affects electrical conductivity in graphene on boron nitride versus silicon dioxide, revealing that boron nitride significantly reduces phonon scattering and enhances mobility at room temperature.

Contribution

It demonstrates that hexagonal boron nitride reduces remote phonon scattering in graphene more effectively than silicon dioxide, improving room-temperature conductivity.

Findings

hBN causes less phonon scattering than SiO2

Resistivity on hBN is approximately 3 ohms at room temperature

hBN is a promising substrate for graphene electronics

Abstract

The substrate material of monolayer graphene influences the charge carrier mobility by various mechanisms. At room temperature, the scattering of conduction electrons by phonon modes localized at the substrate surface can severely limit the charge carrier mobility. We here show that for substrates made of the piezoelectric hexagonal boron nitride (hBN), in comparison to the widely used SiO$_2$, this mechanism of remote phonon scattering is --at room temperature-- weaker by almost an order of magnitude, and causes a resistivity of approximately 3\,$\Omega$. This makes hBN an excellent candidate material for future graphene based electronic devices operating at room temperature.