Novel Process for Metal Silicide Nanostructures Regarding Cheap and Large-Scale Material Synthesis

Thermoelectric power generation presents a promising and attractive way to utilize waste heat and to generate electricity in remote locations. Thanks to continuing technology development an outlook of converting a significant amount of waste energy comes within reach. The class of structured metal silicide materials (MgSi2, Mn11Si19, CrSi2) is considered a class of sustainable and cost-effective candidates for thermoelectric applications. An important way to improve the effectiveness of these materials is by nanostructuring. Nanostructured metal silicides can be obtained by using a rapid solidification technology, ribbon growth on substrate (RGS), where a mixture of liquid metal and silicon melt is solidified under controlled conditions by cooling on a solid, reusable substrate. This technology allows for low-cost and high-throughput synthesis of silicide materials with controllable structures in the nano- and micrometer range. Crystallizing materials from the melt allows for an easy way to add dopants or alloy with different metals. Controlling the structure and composition offers the opportunity of optimizing the thermoelectric properties of silicides. This paper describes the current status of development and validation process for higher manganese silicides and chromium silicides as demonstrators, as well as future perspectives for TE applications.