Experimental Study on the Improvement of Thermoelectric Performance of N-PbS Through Cl Doping.

Lead-based sulfur compounds have been widely used in middle- and high-temperature thermoelectric fields. Compared with Te and Se, S element has the advantages of abundant content, low price, and high thermal stability of PbS, and thus PbS thermoelectric materials have attracted extensive interest of researchers in recent years. However, the inherent high lattice thermal conductivity of PbS thermoelectric material leads to its low thermoelectric conversion efficiency, which severely limits its application in the field of thermoelectric. In order to reduce the lattice thermal conductivity, Cl doping method was used to improve the thermoelectric properties of PbS. The experimental results show that dendritic PbS-based nanomaterials with controllable morphology were prepared by hydrothermal method, and porous PbS-based bulk materials were formed during sintering. The results showed that the density and lattice thermal conductivity of porous PbS materials doped with Cl were significantly reduced, the carrier concentration was increased, and the thermoelectric properties were significantly improved. The zT value of PbCl_0.02S_0.98 material reached 0.71 at 773 K, which was about 108.8% higher than that of pure PbS. [ABSTRACT FROM AUTHOR]