Sn Doped FeNbSb Half-Heusler Compounds for Tuning Thermoelectric Performance

p-Type FeNbSb-based half-Heusler compounds exhibit promising thermoelectric (TE) performance under high temperatures. Herein, the optimal sintering temperature and pressure of these compounds were determined. Sintering temperature can affect relative density, and consequently, improve TE performance. In addition, a series of Sn-doped FeNbSb compounds was prepared in accordance with the optimal sintering temperature and pressure. Results showed that Sn optimized the power factor and reduced lattice thermal conductivity by enhancing point defect phonon scattering. A high ZT of 0.66 was attained at 923 K for FeNbSb0.84Sn0.16. The findings of this study lay the foundation for reducing the thermal conductivity of FeNbSb-based compounds.