Search

We propose a model for three-terminal thermionic heat engines based on semiconductor heterostructures. According to electron transport theory, we drive the formulas for the charge current and energy current flowing from the electron reservoir and we then obtain the power output and efficiency in the linear and nonlinear regimes. Furthermore, we analyze the performance characteristic of the thermionic heat engine and get the maximum power output by optimizing the performance parameters. Finally, we optimize the thermodynamic performance of the thermionic heat engine by maximizing the product of the power output and efficiency.

We propose a model for a three-terminal quantum well heat engine with heat leakage. According to the Landauer formula, the expressions for the charge current, the heat current, the power output and the efficiency are derived in the linear-response regime. The curves of the power output and the efficiency versus the positions of energy levels and the bias voltage are plotted by numerical calculation. Moreover, we obtain the maximum power output and the corresponding efficiency, and analyze the influence of the heat leakage factor, the positions of energy levels and the bias voltage on these performance parameters.

We propose four different models of three-terminal quantum dot thermoelectric devices. From general thermodynamic laws, we examine the reversible efficiencies of the four different models. Based on the master equation, the expressions for the efficiency and power output are derived and the corresponding working regions are determined. Moreover, we particularly analyze the performance of a three-terminal hybrid quantum dot refrigerator. The performance characteristic curves and the optimal performance parameters are obtained. Finally, we discuss the influence of the nonradiative effects on the optimal performance parameters in detail.

We investigate the efficiency at maximum power of a nanothermoelectric heat engine consisting of one spin-degenerate quantum dot embedded between two reservoirs at different temperatures and chemical potentials in an external magnetic field. Based on the stochastic master equation the maximum power and the corresponding efficiency at maximum power are calculated in different external magnetic fields. The result shows that both the maximum power and the corresponding efficiency at maximum power decrease with an increase of the external magnetic field. In the weak magnetic field the corresponding efficiency at maximum power is slightly larger than the Curzon—Ahlborn (CA) efficiency, while in the large magnetic field it is obviously lower than CA efficiency.

A Brownian microscopic heat engine, driven by temperature difference and consisting of a Brownian particle moving in a sawtooth potential with an external load, is investigated. The heat flows, driven by both potential and kinetic energies, are taken into account. Based on the master equation, the expressions for efficiency and power output are derived analytically, and performance characteristic curves are plotted. It is shown that the heat flow via the kinetic energy of the particle decreases. The efficiency of the engine is enhanced, but the power output reduces as the α shape parameter of the sawtooth potential increases. The influence of the α shape parameter on efficiency and power output is then analyzed in detail.