The Electronic Transport Channel Protection and Tuning in Real Space to Boost the Thermoelectric Performance of Mg Sb Bi near Room Temperature.

The optimization of thermoelectric materials involves the decoupling of the transport of electrons and phonons. In this work, an increased Mg-Mg distance, together with the carrier conduction network protection, has been shown as an effective strategy to increase the weighted mobility ( = ) and hence thermoelectric power factor of Mg Sb Bi family near room temperature. Mg SbBi has a high carrier mobility of 247 cm V s and a record power factor of 3470 W m K at room temperature. Considering both efficiency and power density, Mg SbBi with a high average ZT of 1.13 and an average power factor of 3184 W m K in the temperature range of 50-250°C would be a strong candidate to replace the conventional n-type thermoelectric material BiTeSe. The protection of the transport channel through Mg sublattice means alloying on Sb sublattice has little effect on electron while it significantly reduces phonon thermal conductivity, providing us an approach to decouple electron and phonon transport for better thermoelectric materials.