Thermal and electrical analysis of thermionic emission cooling in semiconductor heterojunctions.

摘要

A thermionic emission cooler is a device that extracts heat from one side of a device by means of the Peltier effect and transports that heat to the other side by means of ballistic electrons. A detailed theoretical analysis of solid-state thermionic emission cooling is presented. It is shown that degenerately doped semiconductors provide optimum conditions for operation, thus requiring a model that includes Fermi-Dirac statistics. Maximum cooling and coefficient of performance are evaluated. Both are shown to depend on a materials parameter that is the same as that for thermoelectric devices. Optimized thermionic emission cooling is compared to bulk thermoelectric cooling as a function of the materials parameter as well as for the specific materials InGaAs and Bi₂Te₃. It is shown that for all known materials thermionic emission cooling is less effective and less efficient than thermoelectric cooling. It is further shown that the inclusion of contact resistance in the theory dramatically reduces the performance of thermionic emission cooling.