Executive Summary : | Thermoelectricity (TE) is a promising green energy source, but its conversion efficiency is low. This study proposes a novel approach to improve TE conversion efficiency by chemically altering the doping concentration in segmented TE generators (TEG). The goal is to achieve TE conversion efficiencies of approximately 20%, similar to commercial solar cells. The proposed approach involves tuning the chemical potential of individual segments, which can be altered by a few orders of magnitude in semiconductors. This requires a detailed understanding of the temperature dynamics of the electronic band structure (EBS) of these materials. The project consists of three parts: synthesizing various state-of-the-art TE materials using melt techniques, studying the EBS and its influence on segmented material efficiency, and experimental preparation and testing of optimized segmented TE legs/modules. In the first part, state-of-the-art TE materials will be synthesized using melt techniques, with doping concentrations varied and thermoelectric properties measured as a function of temperature. The second part will theoretically study the EBS and its influence on segmented material efficiency using multiscale modelling techniques. A technique recently developed by the PI's group will be used for EBS determination. The EBS parameters will be used to solve the heat-flow equation in segmented legs using Finite Difference Method analysis, generating 2-D efficiency maps as a function of n for both segments. For select materials with promising EBS parameters, further details of the electronic and phonon bandstructure will be investigated using standard DFT and MD packages. |