Playing with the thermostat in two dimensions: cooling and heating of graphene

Thermoelectrics is the field of study that deals with situations in which a temperature difference creates an electric potential, or vice versa, an electric potential creates a temperature difference. One example of this is the Peltier effect, which is a temperature difference that appears when a voltage is applied between two electrodes connected to a semiconductor material. The Peltier effect allows the electrical control of cooling and heating.

Researchers from University of Groningen and the University of Manchester have now, for the first time, directly detected the Peltier effect in graphene that is either one or two atoms thick. They unambiguously showed that the effect can be switched from heating to cooling by tuning the type and density of the charge carriers inside the material (Nature Communications, "Direct electronic measurement of Peltier cooling and heating in graphene").