Patent ID: 8159108

Claim:
A device for converting heat into electric power comprising: An emitter, which emits electrons when exposed to heat; A collector, having an approximate operating temperature, for collecting the electrons, wherein the collector is separated from the emitter by a gap, and comprising a metal portion and a coating on the metal portion, wherein the coating is positioned between the metal portion and the gap; Wherein the coating comprises an n-type semiconductor material layer having a crystalline lattice spacing distance, the electrons have a scattering length in the layer, a contact junction exists between the metal portion and the layer, and the thickness of the layer is between three times the scattering length and 100 times the lattice spacing distance; and wherein a Schottky-type barrier exists at the contact junction such that the barrier height is greater than kT C ln(10AT C 2 /J 0 ), where k is the Boltzmann constant, A is the Richardson-Dushman constant and T C is the approximate operating temperature of the collector.