Thermoelectric materials for space explorations

Abstract

This comprehensive review examines the historical development of radioisotope thermoelectric generators (RTGs) over the last fifty years and anticipates future missions, providing insights into the meticulous selection of radioisotope heat sources and thermoelectric (TE) materials throughout the generations of RTGs. It analyzes the TE properties of conventional materials and investigates strategies to improve them, with a special emphasis on a dual-principle approach to increase the dimensionless figure of merit (zT). As advancements in TE materials and RTG design continue, the focus extends beyond TE properties to include other critical factors for effective RTG integration such as durability, safety, and weight.