Hot electron transport in suspended multilayer graphene

TL;DR

This study investigates hot electron transport in suspended multilayer graphene devices, revealing conductance dips and anomalies linked to phonon scattering and weak localization effects, with implications for understanding electron dynamics in 2D materials.

Contribution

It provides experimental insights into hot electron behavior in multilayer graphene, highlighting the effects of contact barriers and temperature on conductance features.

Findings

Conductance dip at zero bias in devices with semi-transparent contacts.

Anomalies at higher bias likely due to optical phonon scattering.

Logarithmic dependence of conductance on bias and temperature explained by hot electron effects and weak localization.

Abstract

We study hot electron transport in short-channel suspended multilayer graphene devices created by a distinct experimental approach. For devices with semi-transparent contact barriers, a dip of differential conductance (dI/dV) has been observed at source drain bias Vd = 0, along with anomalies at higher Vd likely induced by optical phonon scattering. For devices with low contact barriers, only the dI/dV dip at Vd = 0 is observed, and we find a well-fit logarithmic dependence of dI/dV on both the bias Vd and the temperature T. The logarithmic Vd dependence is explained with the hot electron effect and the logarithmic T dependence could be attributed to the weak-localization in two-dimensions.