Abstract The earth‐abundant tin sulfide (SnS) has emerged as an ecologically sustainable alternative for the thermoelectric community recently. However, its wide bandgap (≈46 k B T ) is unfavorable for electrical performance, while the high vapor pressure of the S often results in a relatively low yield of synthesis. In this study, a synergistic strategy is devised to optimize the thermoelectric performance of polycrystalline SnS prepared via a low‐temperature solid‐state synthesis method. First, silver doping increases the hole carrier concentration ( n ) to ≈10 19 cm −3 . Subsequently, through selenium alloying, a dual‐effect can be achieved: the bandgap is narrowed to increase the doping efficiency, while atomic point defects are introduced to lower the thermal conductivity. Ultimately, the polycrystalline Sn 0.98 Ag 0.02 S 0.55 Se 0.45 attains a maximum ZT value of ≈0.9 at 873 K. The study indicates that promising thermoelectric performance can be obtained by a rapid synthesis method through a series of meticulously designed optimization strategies. This achievement offers novel insights and paves the way for the development of sulfide‐based thermoelectrics.
Liu et al. (Fri,) studied this question.