Enhancing\nThermoelectric Performance of p‑Type PbSe through Suppressing\nElectronic Thermal Transports

Abstract

To\ndate, thermoelectric performance has been enhanced through improving\nthe power factor and/or reducing the lattice thermal conductivity.\nHere, we report an effective method of boosting thermoelectric performance\nthrough suppressing electronic thermal transports. In this work, p-type\nPbSe was selected; the thermoelectric performance was gradually improved\nthrough several rational successive steps. First, a thermoelectric\ndimensionless figure of merit (<i>ZT</i>) of ∼0.8\nat 860 K was obtained in p-type PbSe+2Na through optimizing Na doping.\nSecond, the <i>ZT</i> was increased to ∼1.1 at 860\nK in PbSe+2Na+10Te by suppressing the electronic thermal conductivity\nthrough reducing the carrier mobility and increasing the Seebeck coefficients\nafter alloying Te. Finally, the electronic and lattice thermal conductivity\nof PbSe + 2Na + 10Te were simultaneously reduced through Cu doping\nwith the dual roles of electron counter-doping and producing dislocation\ninterstitials. As a result, <i>ZT</i> was further increased\nto ∼1.5 at 860 K, resulting in an average <i>ZT</i> (<i>ZT</i>_ave) ∼ 0.69 at 300–860\nK in PbSe+2Na+10Te+0.5Cu.