Strong interlayer coupling in two-dimensional PbSe with high thermoelectric performance

Z P Yin; C Y Sheng; R Hu; S H Han; D D Fan; G H Cao; H J Liu

doi:10.1088/1361-648X/abcd7d

Strong interlayer coupling in two-dimensional PbSe with high thermoelectric performance

J Phys Condens Matter. 2021 Jun 22;33(32). doi: 10.1088/1361-648X/abcd7d.

Authors

Z P Yin¹, C Y Sheng¹, R Hu¹, S H Han¹, D D Fan¹, G H Cao¹, H J Liu¹

Affiliation

¹ Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, People's Republic of China.

PMID: 33232949
DOI: 10.1088/1361-648X/abcd7d

Abstract

It was generally believed that weak van der Waals interactions exist between neighboring layers in the two-dimensional group-IV chalcogenides. Using PbSe as a prototypal example, we find additional strong coupling between the Pb-Pb layers, as evidenced by detailed analysis of the differential charge density plot. The coupling is covalent-like and can be fine-tuned to obviously reduce the phonon thermal conductivity but slightly change the electronic transport of PbSe layer. As a consequence, a maximumZTvalue of 2.5 can be realized at 900 K for thep-type system. Our work also offers an effective and feasible design strategy to enhance the thermoelectric performance of similar layered structures.

Keywords: Boltzmann transport theory; first-principles; group-IV chalcogenides; interlayer coupling; thermoelectric materials; van der Waals interactions.