Thermoelectric Properties Control due to Doping Level and Sintering Conditions for FGM Thermoelectric Element

Abstract

Thermoelectric performance is detennined with three factors, namely, Seebeck coefficient ,electrical resistivity and thermal conductivity. For metal and single crystalline semiconductor, those factors have close interrelation each other. However, as the sintered thermoelectric element has various levels of superstructure from macro scale and micro scale in terms of the thermoelectric mechanism, the relationship among them is more complex than that for the melt-grown element, so it is suggested that the control of the temperature dependence of thermoelectric properties is possible to enhance the thermoelectric performance for wide temperature range due to FGM approach. The research objective is to investigate the characteristics of the thermoelectric properties for various doping levels and hot-pressed conditions to make the thermoelectric elements for which the temperature dependence of the performance is controlled due to FGM approach varying the doping levels and sintering conditions. By usage of the zone traveling hot-press sintering method to Antimony doped magnesium silicide synthesized by the spark plasma sintering method the continuously, functionally graded, sintered thermoelectric bulk element could be successfully made, and the distribution characteristics of thermoelectric properties were satisfactorily measured.