Direct electronic measurement of Peltier cooling and heating in graphene

TL;DR

This paper presents a direct measurement of Peltier effects in graphene, demonstrating its potential for nanoscale thermoelectric applications and revealing reversible cooling and heating phenomena at room temperature.

Contribution

It provides the first quantitative, direct measurement of Peltier effects in graphene, highlighting its sensitivity to electronic structure asymmetries at the nanoscale.

Findings

Detected Peltier modulation of up to 15 mK at room temperature.

Observed reversal between Peltier cooling and heating for electrons and holes.

Demonstrated graphene's potential for nanoscale thermoelectric control.

Abstract

Thermoelectric effects allow the generation of electrical power from waste heat and the electrical control of cooling and heating. Remarkably, these effects are also highly sensitive to the asymmetry in the density of states around the Fermi energy and can therefore be exploited as probes of distortions in the electronic structure at the nanoscale. Here we consider two-dimensional graphene as an excellent nanoscale carbon material for exploring the interaction between electronic and thermal transport phenomena, by presenting a direct and quantitative measurement of the Peltier component to electronic cooling and heating in graphene. Thanks to an architecture including nanoscale thermometers, we detected Peltier component modulation of up to 15 mK for currents of 20 $\mu$A at room temperature and observed a full reversal between Peltier cooling and heating for electron and hole regimes. This fundamental thermodynamic property is a complementary tool for the study of nanoscale thermoelectric transport in two-dimensional materials.