High-Performance Functionalized Mg2Si0.9Sn0.1 Thermoelectric Leg Synthesis by a Single-Step Reactive SPS Process

Contact electrodes and their adequate joining are the main bottlenecks in realizing low-cost Mg2(Si,Sn) thermoelectric materials for thermoelectric generator applications. The resistance and diffusion chemistry between the thermoelectric elements and contact electrodes play an essential role in achieving high-performance thermoelectric generators for intermediate-temperature applications. A facile single-step spark plasma sintering process was employed to fabricate Sb-doped Mg2Si0.9Sn0.1 and contact joining simultaneously. The single-step-processed thermoelectric element’s power output characteristics with three different contacts (Ni, MnSi, and FeSi2) were investigated by employing a thermoelectric conversion efficiency evaluation system. Our experimental strategy demonstrated that the single-step processing of Mg2(Si0.9Sn0.1)0.95Sb0.05/Ni joining imparts the lowest internal resistance and high-power output characteristics and eliminates the main obstacle of Mg2(Si,Sn) material integration in thermoelectric power generators.