Electronic structure modulation of Pb0.6Sn0.4Te via zinc doping and its effect on the thermoelectric properties

Striking a balance between the high performance and detrimental environmental toxicity of PbTe materials in thermoelectrics (TE) has become a necessity in the current situation. In this context, improving the performance of materials with lower lead content to the level of PbTe is crucial. Herein, we engineer the electronic structure of Pb0.6Sn0.4Te, a well-known TCI but a poor TE material by doping Zn. The first prin ciples calculation reveal that Zn doping introduces multiple electronic valleys while simultaneously opening the band gap of Pb0.6Sn0.4Te. Higher power factor with lower thermal conductivity is predicted by the transport property calculations in the doped material. The resonance level introduced along with features of hyper-convergence of the valence bands leads to improved Seebeck co-efficient throughout the studied temperature range. An experimental figure of merit, ZT of similar to 1.57 at 840 K promises us a TE material applicable for a broad temperature range for future energy applications. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study focuses on improving the performance of thermoelectric material Pb0.6Sn0.4Te by doping Zn to enhance power factor, reduce thermal conductivity, and improve Seebeck coefficient. The introduction of multiple electronic valleys and band gap opening through Zn doping show promising results for future energy applications, with an experimental figure of merit ZT of 1.57 at 840K.