Achieving high thermoelectric performance in metal sulfide PbSnS 2 through strain-mediated lone-pair expression amplification and multi-band conduction

Strain engineering in PbSnS 2 suppresses κ L by enhancing lone-pair electron expression and decouples S and σ via activating multi-band conduction, yielding a high zT of 1.2 at 900 K under −2% compressive strain.