Enhanced thermoelectric properties of PbBiS prepared with hydrothermal synthesis and microwave sintering.

As a cheap substitute for PbTe or PbSe, the thermoelectric performance of PbS still remains to be improved. In this report, we selected BiS as a donor and employed a facile route of hydrothermal synthesis combined with microwave sintering to fabricate BiS doped PbS. Due to the increased electrical conductivity by BiS doping and the decreased thermal conductivity from the refined microstructure, the thermoelectric figure of merit ZT of microwave sintered PbBiS and PbBiS reached 0.90 and 0.86 at 800 K, respectively, without sign of saturation. When processed with plasma activated sintering (PAS), the highest ZT value of PbBiS only reached 0.3 at 800 K. The obtained results indicate that hydrothermal synthesis and microwave sintering can essentially improve the thermoelectric properties of PbBiS and easily realize mass production at low cost.