A Thermoelectric(TE) material can convert heat energy into electricity and vice versa. Since huge amount of heat energy is being released into the environment during various processes (industrial furnaces/chimneys, car exhaust etc.), it is desirable to use TE devices to scavenge the waste heat and turn it into clean energy. However, their low conversion efficiency makes TEs economically nonviable. This efficiency is measured in terms of a dimensionless quantity called the TE figure-of-merit, ZT, where T stands for temperature, and Z is given by: 𝑍 = 𝜎𝑆2⁄𝜅 where 𝜎 and 𝜅 are the electrical and thermal conductivities, and S is the thermopower. TEs with ZT > 2 can enhance the power generation efficiency by 10 % to 15 %. Therefore, it is crucial to discover new TE materials with high ZT. The intermetallic Half-Heusler (HH) alloys (chemical formula: XYZ) are promising materials in this regard. Though traditionally studied for spintronics, recently they have attracted considerable attention for topological and thermoelectric properties.

NASA has been using Radioisotope Thermoelectric Generators (RTGs) for decades. They use radioactive plutonium oxide as a fuel (heat source) and power their deep space probes by converting heat into electricity using thermoelectric material.