Improving the thermoelectric performance of p-type PbSe via synergistically enhancing the Seebeck coefficient and reducing electronic thermal conductivity

Abstract

In this work, the thermoelectric performance of p-type PbSe was improved dramatically by enhancing the Seebeck coefficient and reducing electronic thermal conductivity through CdTe alloying. CdTe alloying effectively increased the effective mass of p-type Pb_0.98Na_0.02Se due to band flattening and promoting the valence band convergence, which contributed to a high Seebeck coefficient of ∼238 μV K⁻¹ at 860 K and large power factor of ∼18.2 μW cm⁻¹ K⁻² at 860 K for Pb_0.98Na_0.02Se + 4% CdTe. Furthermore, CdTe alloying reduced the carrier mobility of Pb_0.98Na_0.02Se due to the enhanced scattering of impurity atoms, which results in a remarkable reduction of electronic thermal conductivity. As a result, due to its higher power factor and lower thermal conductivity, a high thermoelectric figure of merit ZT ∼1.5 at 860 K was achieved for Pb_0.98Na_0.02Se + 4% CdTe. This paper provides one novel approach to enhance the thermoelectric performance of p-type PbSe through synergistically manipulating electrical and thermal transport properties.