Enhanced Peltier Cooling Through Electron Gas Expansion and Thomson Cooling

Traditional Peltier thermoelectric modules are the current state of the art for small-scale solid-state. However, their cooling power density is limited by the material thermoelectric figure of merit. Methods to break beyond the traditional thermoelectric limits are of interest for micro-nano scale electronic cooling applications. In this presentation, I will discuss two hybrid methods to improve cooling efficiency, electron gas expansion cooling and Thomson cooling combined with Peltier cooling. Recently, we used an ensemble Monte Carlo simulation to demonstrate the non-equilibrium expansion of an electron gas using nanoscale trapezoidal geometric confinement. Formation of a nozzle structure leads to the expansion of electrons emitted from the cathode under an applied bias, which in turn results in additional cooling beyond the Peltier cooling. The proposed device operates under steady-state conditions, providing enhanced cooling compared to a one-dimensional flat geometry. We observe a five-fold increase in both the maximum cooling temperature and cooling power density when comparing the trapezoidal geometry to the regular flat geometry. I will also briefly discuss Thomson cooling which provides extra cooling when combined with Peltier cooling. Several materials wherein large Thomoson coefficients were measured will be discussed.
This presentation is in memory of Dr. Natalio Mingo.