Enhancing thermoelectric transport properties of n-type PbS through introducing CaS/SrS

N-type PbS have been studied widely for purpose of substituting PbTe attributed to the low price and high earth abundance of sulfur element and it is significant to research the strategy of boosting the thermoelectric performance of PbS through adjusting carrier and phonon transports synergistically. Here, the thermoelectric performance of n-type PbS is enhanced effectively by introducing CaS/SrS. CaS/SrS alloying could simultaneously enhance Seebeck coefficients and reduce lattice thermal transport properties over broad temperature range. As a consequence, the maximum thermoelectric figure of merit (ZT) ~ 1.2 at 930 K and high average ZT (ZT_ave) ~0.8 at 423 K–930 K are obtained for n-type PbS+3%CaS/SrS+1%PbCl₂ based materials. These results indicate that the methods of CaS/SrS alloying have great prospect in improving thermoelectric performance of n-type PbS.