First-principles study of wrinkled SnTe monolayer as p-type thermoelectric material

Abstract

Tin telluride compounds are promising thermoelectric (TE) materials on account of the excellent electronic and thermal transport properties. The present work focuses on examining the TE performance of a two-dimensional wrinkled SnTe monolayer by employing the first-principles calculations and Boltzmann transport theory. The SnTe monolayer demonstrates high mechanical, dynamic and thermal stabilities, which have been thoroughly investigated using the elastic modulus, formation energy and ab initio molecular dynamics simulations. The lattice thermal conductivities of the SnTe monolayer along the zigzag- and armchair-direction are 11.29 and 12.40 W/mK at 300K, respectively. Due to the large Grüneisen parameters, short phonon relaxation time and low phonon group velocity, the p-type SnTe monolayer exhibits high TE performance at 900 K, as characterized by a high ZT of 1.44 along the zigzag-direction. Our present study not only offers valuable insights into the TE properties of the wrinkled SnTe monolayer, but also sheds some light on the theoretical designing of the novel SnTe-based material for TE applications.