Monte Carlo simulation of transient electron gas energy conversion thermodynamic cycle in GaAs

We present Monte-Carlo (MC) simulations and analyses of a newly proposed thermodynamic cycle in a solid-state regime, which is fundamentally apart from well-known solid-state thermoelectric or thermionic generators. The thermodynamic cycle is designed in analogy to the Otto cycle and includes compression, heating, and release of electronic gas. During the electron gas expansion, part of the energy is delivered to the load, and part of it is rejected to the lattice. Considering the non-equilibrium and the transient nature of the device, it is not limited by the Carnot efficiency. We show that thermal efficiencies higher than 70% are possible when the input heat is small. As we increase the input heat, the efficiency drops significantly and approaches a few percent due to larger electron-phonon interaction rates for higher energy electrons.