Enhanced thermoelectric performance actuated by inelastic processes in the channel region

Abstract

I propose a design strategy to enhance the performance of heat engine via absorption of thermal energy from the channel region. The absorption of thermal energy can be actuated by inelastic processes and may be accomplished by an energy restrictive flow of electrons into the channel. The proposed design strategy employs dual energy filters to inject and extract electrons through the contact to channel interface. The first filter injects a compressed stream of electrons from the hot contact, at an effective temperature much lower than the channel temperature. The compressed stream of injected electrons, then, absorb energy via inelastic scattering inside the channel and are finally extracted via a second filter at the cold contact interface. Rigorous mathematical derivations demonstrate that an optimized performance for the proposed design strategy demands the implementation of a box-car transmission function at the electron injecting terminal and a unit-step transmission function at the electron extracting terminal. Numerical simulation show that in the proposed design strategy, the heat engine performance, under optimal conditions, can surpass the ballistic limit when the required output power is low compared to the quantum bound. The proposed concept can be used to construct high efficiency thermoelectric generators in situations where the source of usable heat energy is limited, but insulated from environmental dissipation.