III-V based heterostructure integrated thermionic coolers

Solid state coolers based on III-V materials can be monolithically integrated with optoelectronic and high-speed electronics components. The use of thermionic emission in heterostructures will permit enhanced cooling capacities beyond the linear transport regime. Monte Carlo calculations are used to study the main energy relaxation mechanisms in III-V thin barrier heterostructures, i.e., polar optical phonon and intervalley scattering. The bias dependence of electron energy relaxation length is analyzed and important parameters for the design of heterostructure integrated thermionic (HIT) coolers are identified. Single-stage InGaAsP based HIT coolers have been fabricated and characterized. Cooling up to 0.7 K over a one micron thick barrier has been measured