With over half of global energy wasted as heat, it is critical from both an environmental and economic standpoint to make use of this underutilised energy waste. Thermoelectric (TE) power directly converts heat to electricity through the Seebeck effect in a TE material, with potential applications to energy harvesting and for improving energy efficiency at multiple scales. The performance of a TE material is expressed by the figure of merit ZT : ZT = S 2 σ T