ICT2014 Abstracts

Mg₂Si is a candidate for thermoelectric power generator (TEG) applications; however, one concern about it Mg₂Si is that it predominantlydisplays n-type conductivity. Thus, the fabrication of a Π-structure TEG requires a counterpart p-type material, while the use of n-type Mg₂Si alone is another possibility for fabricating a unileg TEG structure. Nevertheless, Mg₂Si has several promising features, such as the abundance of elements, its non-toxicity, and the facts that it’s light-weight and has the capability of becoming a candidate material for TEG applications. We've attempted to realize a unileg TEG by using solely n-type Mg₂Si. We report on the power generation characteristics of a unileg structure TE module based on an n-type Mg₂Si chip using finite-element modeling with the ANSYS. The expected power generation characteristics, such as the open circuit voltage (V_OC), the short circuit current (I_SC), and the power curve of the TE chip and a basic unileg module were evaluated. Regarding the ANSYS calculation, elemental n-type Mg₂Si TE chips with dimensions of 3x3x5.0 to 5x5x10 mm³ were examined, then unileg structures consisting of dual-TE-chips as a basic TEG model were evaluated in terms of possible maximum output power and thermal loss peculiar to the unileg configuration. For the ANSYS calculation, it should be noted that the fundamental TE data of the Seebeck coefficient, the electrical conductivity, and the thermal conductivity as a function of temperature were initiated from the measured values of a fabricated TE chip consisting of Mg₂Si. To understand the optimal output power for the device, we calculated several  TE chips and unileg configuration at temperature differences at ΔT=500 K of between 873K and 373K. We fabricated an actual unileg TEG and measured its power curves, and then we compared the measured data with the calculation results.