Fig. 5: Thermoelectric properties of NaxSn0.995–xSe before and after the purification process.
From: Polycrystalline SnSe with a thermoelectric figure of merit greater than the single crystal
a, Electrical conductivity (σ). b, Seebeck coefficient (S). c, Power factor (PF). d, ZT values of polycrystalline NaxSn0.995–xSe developed in this work and current-state-of-the-art polycrystalline thermoelectrics, 2%Na-doped PbTe-8%SrTe8 (filled pink) and ball-milled and H2-reduced SnSe-5%PbSe doped with 1% Na12 (filled green) and single-crystal SnSe, undoped (p-type, open orange)9, single-crystal Na-doped (p-type, open blue)10 and single-crystal Br-doped SnSe11 (open black). Polycrystalline samples were measured parallel to the SPS direction. The typical uncertainty of 10% for ZT estimates is given.
