High-Field Electrical and Thermal Transport in Suspended Graphene

TL;DR

This study investigates the high-field electrical and thermal transport properties of suspended graphene at temperatures exceeding 1000 K, revealing superior performance metrics compared to silicon and insights into heat and charge flow at extreme conditions.

Contribution

It provides the first comprehensive measurements of high-temperature, high-field transport properties of suspended graphene, highlighting its potential for extreme environment applications.

Findings

Peak saturation velocity of 3.6x10^7 cm/s at 1000 K

Thermal conductivity of 530 W/m/K at 1000 K

Behavior of cleaner devices approaches intrinsic properties

Abstract

We study the intrinsic transport properties of suspended graphene devices at high fields (>1 V/um) and high temperatures (>1000 K). Across 15 samples, we find peak (average) saturation velocity of 3.6x10^7 cm/s (1.7x10^7 cm/s), and peak (average) thermal conductivity of 530 W/m/K (310 W/m/K), at 1000 K. The saturation velocity is 2-4 times and the thermal conductivity 10-17 times greater than in silicon at such elevated temperatures. However, the thermal conductivity shows a steeper decrease at high temperature than in graphite, consistent with stronger effects of second-order three-phonon scattering. Our analysis of sample-to-sample variation suggests the behavior of "cleaner" devices most closely approaches the intrinsic high-field properties of graphene. This study reveals key features of charge and heat flow in graphene up to device breakdown at ~2230 K in vacuum, highlighting remaining unknowns under extreme operating conditions.