Highly enhanced thermoelectric properties of Cu1.8S by introducing PbS

Cu1.8S+ x wt% PbS (x = 0, 0.5, 1, 2, 3) bulk samples were fabricated via mechanical alloying (MA) and spark plasma sintering (SPS) technique by using PbS as the additive. The PbS is an efficient approach in optimizing the TE properties of Cu1.8S. For the sample with additional PbS, the nano grains and the PbS second phase attribute to the enhanced ZT of 1.1 at 773 K for Cu1.8S with 2% PbS, which is the highest value in Cu-S system at this temperature.253