Exploring best thermoelectric efficiency from of more than 10⁴ explored thermoelectric materials and 10⁸ device efficiency calculations

A thermoelectric device is a heat engine that directly converts thermal energy into electrical energy through the Seebeck and Peltier effects. More than tens thousands thermoelectric materials have been reported and numerous high ZT materials have been developed. However, the achievable thermoelectric efficiencies are not known for explored thermoelectric materials. Here, we report the theoretical best thermoelectric efficiencies of each thermoelectric material in a large materials dataset (Starrydata2 thermoelectric web DB [1]). The dataset was filtered to remove erroneous data, and thermoelectric material and device efficiencies were computed by solving the thermoelectric integral equations [2]. The achievable theoretical efficiencies were explored for various thermal and electrical conditions, i.e., over 1,615,713 material efficiency data and 97,841,810 device efficiency data. Finally, the achievable best thermoelectric efficiencies were calculated: 33% at the side temperature (T_h) of 1400 K for an infinite cascade device, 24% at T_h = 1100 K for a multistage P-N leg pair device, and 17% at T_h = 860 K for a single-stage P-N leg device. This study highlights the gap between theoretical material performance and experimental device performance in thermoelectric power generation. The result of this work cab be found in arXiv:2210.08837 [3].