Enhancing Thermoelectric Performance of p-Type PbSe through Suppressing Electronic Thermal Transports

To date, thermoelectric performance has been enhanced through improving the power factor and/or reducing the lattice thermal conductivity. Here, we report an effective method of boosting thermoelectric performance through suppressing electronic thermal transports. In this work, p-type PbSe was selected; the thermoelectric performance was gradually improved through several rational successive steps. First, a thermoelectric dimensionless figure of merit (ZT) of ∼0.8 at 860 K was obtained in p-type PbSe+2Na through optimizing Na doping. Second, the ZT was increased to ∼1.1 at 860 K in PbSe+2Na+10Te by suppressing the electronic thermal conductivity through reducing the carrier mobility and increasing the Seebeck coefficients after alloying Te. Finally, the electronic and lattice thermal conductivity of PbSe + 2Na + 10Te were simultaneously reduced through Cu doping with the dual roles of electron counter-doping and producing dislocation interstitials. As a result, ZT was further increased to ∼1.5 at 860 K, resulting in an average ZT (ZTave) ∼ 0.69 at 300–860 K in PbSe+2Na+10Te+0.5Cu.