Recent advances on Mg2Si1−xSnx materials for thermoelectric generation

Thermoelectric generators (TEGs) have been identified as a viable technology for waste energy harvesting, from heat into electricity. Key to successful realization of this technology on a commercial scale lies largely with the thermoelectric material which drives this technology. While bismuth telluride based TEGs dominate the current market, liabilities such as toxicity, depletion of raw resources and high production costs have triggered the search for alternative thermoelectric materials. One of the contenders as thermoelectric materials in the mid-temperature range is the family of Mg-Mn silicides, given the advantages of abundance of raw resources, relatively high thermoelectric performance, lowered production costs, and environmental compatibility. In this paper, the thermoelectric performance of this class of materials is first reviewed through the key thermoelectric parameters: thermal and electrical conductivity, Seebeck coefficient and power factor. The development fabrication processes for this class of materials, using nanostructuring and element doping strategies, are then elaborated. Finally, comments on the thermoelectric applications and device efficiency are made within the context of this material.