Finite-Element Modeling and Analytical Study of 2D Quantum Confinement Effect on the Thermoelectric Properties

Abstract

[ES] En este trabajo se investigan métodos existentes y nuevos de medición de propiedades termoeléctricas (conductividades térmica y eléctrica, coeficientes de Seebeck y Hall) para geometrías bidimensionales tipo película. Estas propiedades son imprescindibles para un correcto diseño de aparatos sofisticados, como sensores y actuadores o generadores de electricidad en satélites.

Cada uno de los casos de estudio se analiza con el programa de investigación basado en elementos finitos FEAP, procedente de la Universidad de California en Berkeley. De entre los casos más sencillos, usados como validación, se aportan y se comparan soluciones analíticas y/o experimentales. Sobre las simulaciones más avanzadas, se realizan estudios paramédicos y se extraen conclusiones para mejorar los métodos de ensayo de laboratorio.

[EN] In this work, physical properties of thermoelectric materials are investigated. For the performance enhancement of these materials, state-of-the-art techniques are reviewed. An accurate estimation of the properties of thin films is important for the correct material selection for further applications. Methods such as Direct and Alternate Current applied to the Hall bars and Van der Pauw geometries are investigated for measurements of electrical conductivity and Hall coefficient. These methods were simulated with the finite element method software F EAP. The analysis of the most common errors and the influence of the magnetic field on thermoelectric properties are provided. Finally, an experiment from recent research technique for Seebeck and Hall coefficients estimation was repeated with F EAP simulation. It is important to mention that prior to the study of the material characterization, validation of the galvanomagnetic effect is carried out by comparing the analytical and the F EAP results. Throughout the work the graphical post-processing and figures are done with GNUPlot and Adobe Illustrator®. All the calculations are done with M athematica® and M atlab®.