Effects of graphite additives in polycrystalline SnS nanostructures for thermoelectric applications

SnS is one of the most promising layered chalcogenide materials for thermoelectric applications. Novel SnS/Graphite composites were prepared by the one-pot hydrothermal technique to improve the electrical transport properties. Grain boundary scattering and stacking faults introduced by the synthesis method resulted in reduced thermal conductivity of SnS to 0.247 W/mK at 643 K. However, the inclusion of graphite enhanced the crystallinity and carrier concentration by three orders from 4.34 × 10¹⁵ cm⁻³ to 2.06 × 10¹⁸ cm⁻³ at room temperature, resulting in increased electrical conductivity from 16.25 S/m in pristine to 432.80 S/m for SnS/G (wt 10%) sample at 643 K. An improved power factor value of 6.63 µW/mK² was observed for SnS (1 wt%) sample with enhanced electrical conductivity.