Enhanced thermoelectric performance of PbTe based materials by Bi doping and introducing MgO nanoparticles

Abstract

p-type PbTe has long been realized as an excellent thermoelectric (TE) material in the mediate temperature range; however, its counterpart, n-type PbTe, presents poor TE performance. In order to enhance the thermoelectric performance of n-type PbTe, Pb0.995Bi0.005Te-based composites incorporated with MgO nanoparticles have been prepared, and their thermoelectric properties are investigated. The results show that the power factor can be enhanced by incorporation of MgO nanoparticles at high temperature due to the optimized carrier concentration and remarkable energy filtering effects, and the reduced lattice thermal conductivity is obtained owing to interface scattering. Consequently, the sample Pb0.995Bi0.005Te + 0.3 wt. % MgO presents the largest ZT value, reaching 1.4 at 773 K, indicating that incorporation of MgO in Pb0.995Bi0.005Te is an effective approach to improve its thermoelectric performance.