Limits on electron quality in suspended graphene due to flexural phonons

TL;DR

This paper investigates how flexural phonons limit electron mobility in suspended graphene at temperatures above 10 K, showing that they cause resistivity to increase quadratically with temperature and can be mitigated by strain or substrates.

Contribution

It provides a detailed analysis of flexural phonons as the dominant scattering mechanism in suspended graphene at elevated temperatures, quantifying their impact on electron mobility.

Findings

Flexural phonons dominate scattering above 10 K in suspended graphene.

Resistivity increases quadratically with temperature due to flexural phonons.

Applying strain or substrates can eliminate the effect of flexural phonons.

Abstract

The temperature dependence of the mobility in suspended graphene samples is investigated. In clean samples, flexural phonons become the leading scattering mechanism at temperature $T \gtrsim 10\,\,$K, and the resistivity increases quadratically with $T$. Flexural phonons limit the intrinsic mobility down to a few $\text{m}^2/\text{Vs}$ at room $T$. Their effect can be eliminated by applying strain or placing graphene on a substrate.