Modelling and experimental verification of a Ge/SiGe thermoelectric generator

Abstract

Thermoelectric generators (TEG) are devices that generate electricity when a temperature gradient is created across it. Therefore these generators can be used to power micro-scaled devices by harvesting the heat that is released to the environment in different systems. This work presents the Finite Element (FE) model and experimental approaches for investigating the performance of a Ge/SiGe-based TEG. The TEG studied in this work was fabricated using a novel p- and n-type nano-fabricated 2-D Ge/SiGe superlattice grown by low-energy plasma-enhanced chemical vapour deposition (LEPECVD). A single p- and n-leg were coupled together using indium as the bonding material. Results for open and short circuit voltages are presented, using both the experimental and FE modeling approaches. An effective Seebeck voltage of 200μV/K and a maximum power density of 60μW/m2 with a temperature difference of 1.15 K were obtained for this device. The FE model was validated using an analytical method in open circuit and both results closely matched. Although the fabricated module is unoptimized at this stage, it is hoped that the FE model will be used to design an optimal and feasible TEG module in the near future, using an improved Ge/SiGe-based material.