  A new method of electronic refrigeration based on resonant Fowler-Nordheim
emission is proposed and analyzed. In this method, a bulk emitter is covered
with a-few-nm-thick film of a widegap semiconductor, creating an intermediate
step between electron energies in the emitter and in vacuum. An external
electric field tilts this potential profile, forming a quantum well, and hence
2D electron subbands at the semiconductor-vacuum boundary. Alignment of the
lowest subband with the energy levels of the hottest electrons of the emitter
(a few $k_{B}T$ above its Fermi level) leads to a resonant, selective emission
of these electrons, providing emitter cooling. Calculations show that cooling
power as high as 10^{4} W/cm^{2} (at 300 K), and temperatures down to 10 K may
be achieved using this effect.
