Direct electronic measurement of Peltier cooling and heating in graphene

• Published in: Nature communications 2016-05, Vol.7 (1), p.11525-11525, Article 11525
• Main Authors: Vera-Marun, I. J., van den Berg, J. J., Dejene, F. K., van Wees, B. J.
• Format: Article
• Language: English
• Subjects: 639/301/299/2736; 639/766/25; 639/925/357/918; Asymmetry; Cooling; Graphene; Heat; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms11525

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 μA 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. The interaction of electric and thermal transport phenomena at the nanoscale leads to Seebeck and Peltier thermoelectric effects. Here, the authors directly detect the Peltier effect in graphene, and show that it can be reversed by controlling the type and density of the majority carriers using a back gate.