Enhanced thermoelectric properties of Pb1-xBixS 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 Bi2S3 as a donor and employed a facile route of hydrothermal synthesis combined with microwave sintering to fabricate Bi2S3 doped PbS. Due to the increased electrical conductivity by Bi2S3 doping and the decreased thermal conductivity from the refined microstructure, the thermoelectric figure of merit ZT of microwave sintered Pb0.995Bi0.005S and Pb0.99Bi0.01S 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 Pb0.99Bi0.01S only reached 0.3 at 800 K. The obtained results indicate that hydrothermal synthesis and microwave sintering can essentially improve the thermoelectric properties of Pb1-xBixS and easily realize mass production at low cost.