Electronic Thermoelectric Power Research Articles

Extension of Mott Formula in the Linearized Boltzmann Transport Equation to the Study of Thermoelectric Power of Electron in Metal

The focus of this paper is to compute and study thermoelectric power of electron in metals using Mott formula based on free electron theory to get an insight on the effect of strain on electron thermoelectric power in metals. Electron density parameter of strained metals and Poisson ratio of metals is obtained and used in this work unlike some researchers that assumed a value for Poisson ratio of all metals. This assumption make the electron density parameter of strained and unstrained metals to be equal and then reduce the computation to only one input parameter. The experimental and simulated value are in good agreement. This agreement is due to the usefulness of free electron theory in theoretical forecast of some properties of metals. The Poisson ratio is involved in simulation. Result obtained revealed that thermoelectric power of electron in metals goes up as the electron density parameter rises due to high-order contributions from electron scattering theory. Electron thermoelectric power in metals increases as the temperature increases due to electron thermal excitation from their mean position. The electron thermoelectric power rises as strain rises for metals.

The Effect of Width-Mismatch of Modulated Nanowaveguides on the Thermoelectric Efficiency.

Width-modulated nanowaveguides are promising for thermoelectric efficiency enhancement because electron and phonon transport properties can be geometrically tuned for improved performance. The shape of the modulation profile drastically affects the transport properties. Optimization of the width modulation for simultaneous maximum thermoelectric transport and minimum thermal transport is challenging because of the interconnected electron and phonon transport properties. We addressed this problem by analysing the effect of each characteristic dimension of a single rectangular modulation unit on electron and phonon transport. We identified distinct behaviours for electrons and phonons. We reveal that whereas phonon thermal conductance decreases with increasing width-mismatch, the electron thermoelectric power factor shows a non-monotonic dependence. It is pointed out that optimal width-mismatch that maximizes thermoelectric efficiency is mainly determined by electron transport and should be identified by maximizing the thermoelectric power. Our work points to a new strategy of optimizing geometry-modulated metamaterials for maximum thermoelectric efficiency.

Fermi energy and electron thermopower in quantum films of an asymmetric profile

The behavior of the Fermi energy and the electron thermoelectric power in an asymmetric quantum well of the Morse potential type as a function of electron concentration are studied. It is shown that the Fermi energy is a piecewise-linear function, and the electron thermoelectric power is an oscillating function. The analysis shows that the nature of these oscillations differs significantly from that in films of a parabolic and rectangular profile, namely, the oscillation period is a nonmonotonic function and reaches a maximum at some value of the electron concentration. The possibility of estimating the parameters of the film profile (quantum well) is proposed. A comparison with the experiment shows a qualitative agreement.

Influence of the cation sublattice defectness on the electronic thermoelectric power of Li x Cu(2−x)−δ (x ≤ 0.25)

This paper presents an experimental study of the electronic thermoelectric power as a function of copper content for LixCu(2−x)−δS (x ≤ 0.25) electronic-ionic mixed conductors. Using a vacancy model for lattice defects, we calculate their electronic thermoelectric power as a function of x. By adjusting the hole effective mass, we reach satisfactory agreement with experimental data.

Negative Longitudinal Magneto-Thermoelectric Power in a Semiconductor Parabolic Quantum Well

We present a theoretical study of the electronic thermoelectric power of a semiconductor parabolic quantum well in a magnetic field. The case of a longitudinal magnetic field, with respect to the temperature gradient, has been considered. The calculations were carried out taking into account the spin-splitting of dimensionally quantized electronic energy levels. It has been shown that in the region of strong confinement the thermoelectric power decreases with increasing magnetic field, which is related to the downward shift of the lower Zeeman-split spin subband.