Load-Bearing Figure-of-Merit Characterization of a Thermoelectric Module

Thermoelectric behavior in semiconductor materials is investigated for the purpose of converting thermal energy to electrical energy. This paper measures and quantifies the variations in the internal electrical and thermal resistances of a thermoelectric module with respect to the circuit's electrical load in order to better characterize its behavior in a closed circuit. Since open-circuit measurements fail to accurately describe thermoelectric material properties in power generation mode, the load-bearing Seebeck coefficient and the load-bearing figure-of-merit are defined, measured, and discussed. It is shown that the load-bearing Seebeck and the load-bearing figure-of-merit are more accurate parameters in measuring a module's ability to operate in thermoelectric power generation mode. In particular, there exist peak load-bearing characteristics that are not identified using the conventional open-circuit definitions of the Seebeck coefficient and the figure-of-merit. The results show that the peak load-bearing figure-of-merit is compared with the peak power output showing a misalignment between the two quantities, the significance of which is discussed.