With continued growth in the global demand for energy and the urgent need to reduce greenhouse gas (GHG) emissions to limit anthropogenic climate change, the importance of technologies to provide clean energy and enhance the efficiency of use cannot be understated. A substantial proportion of the industry and technology that underpin modern life generates waste heat, with an estimated 60% of global energy lost through this route. In particular, the difficult to decarbonise industry and transport sectors were estimated to be responsible for ∼24 and 16% of GHG emissions in 2016, highlighting the significant potential for reductions from improving efficiency. Thermoelectric generators (TEGs) are solid-state devices that convert thermal energy directly to electricity via the Seebeck effect in a thermoelectric material. TEGs have no moving parts, and are thus easy to maintain, have proven reliability in the aerospace industry, and are potentially scaleable to a wide range of applications. The performance of a TE material is measured using the dimensionless figure of merit ZT defined by: 1,3