The increased number of carrier pockets near the Fermi level and the optimized carrier concentration in doped SnSe single crystal can lead to a high averageZTave∼ 1.2 from 300 K to 800 K and a peakZTmaxvalue in excess of 2.0 at 800 K along the crystallographicb-axis.

Doping Cu2Se with Sn enhances the thermoelectric figure of merit and decreases material degradation in thermoelectric power generation conditions.

Grain boundary scattering is the dominant reason for the deteriorated performance of polycrystalline SnSe compared to single crystals.