Raising the thermoelectric performance of PbS with low-content polyparaphenylene

Lead sulfide (PbS), a promising medium-temperature thermoelectric material, is a cheap and excellent substitute for lead pyride. However, its high thermal conductivity limits its thermoelectric properties strongly. In this paper, the nanocomposites with PbS matrix and organic conducting polymer polyparaphenylene (PPP) supplement are introduced to decrease the thermal conductivity by mechanical mixing method. The experimental results show that the thermal conductivity of PbS–PPP nanocomposites significantly decreases and the minimum thermal conductivity is 0.43 W m −1 K −1 , which can be obtained when the mass ratio of the PPP is 3% at 773 K. Consequently, the figure of merit (ZT) of PbS–PPP nanocomposites reaches as large as 0.5, which is 52.40% of magnitude higher than that of pure PbS. Therefore, it is an effective way to improve the thermoelectric properties of PbS by introducing the organic conducting polymer PPP. This work may shed light on developing high-performance thermoelectric materials via organic–inorganic nanocomposites at the intermediate temperature range.