Structure Low Dimensionality and Lone-Pair Stereochemical Activity: the Key to Low Thermal Conductivity in the Pb–Sn–S System - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of the American Chemical Society Année : 2024

Structure Low Dimensionality and Lone-Pair Stereochemical Activity: the Key to Low Thermal Conductivity in the Pb–Sn–S System

Bin Zhang
P. Lemoine
Bernard Malaman
Blas P. Uberuaga
Christophe Candolfi
Xiaoyuan Zhou

Résumé

Recently, metal sulfides have begun to receive attention as potential cost-effective materials for thermoelectric applications beyond optoelectronic and photovoltaic devices. Herein, based on a comparative analysis of the structural and transport properties of 2D PbSnS2 and 1D PbSnS3, we demonstrate that the intrinsic effects that govern the low lattice thermal conductivity (κL) of these sulfides originate from the combination of the low dimensionality of their crystal structures with the stereochemical activity of the lone-pair electrons of cations. The presence of weak bonds in these materials, responsible for phonon scattering, results in inherently low κL of 1.0 W/m K in 1D PbSnS3 and 0.6 W/m K in 2D PbSnS2 at room temperature. However, the nature of the thermal transport is quite distinct. 1D PbSnS3 exhibits a higher thermal conductivity with a crystalline-like peak at low temperatures, while 2D PbSnS2 demonstrates glassy thermal conductivity in the entire temperature range investigated. First-principles density functional theory calculations reveal that the presence of antibonding states below the Fermi level, especially in PbSnS2, contributes to the very low κL. In addition, the calculated phonon dispersions exhibit very soft acoustic phonon branches that give rise to soft lattices and very low speeds of sounds.

Domaines

Chimie
Fichier non déposé

Dates et versions

hal-04571271 , version 1 (07-05-2024)

Identifiants

Citer

Paribesh Acharyya, Koushik Pal, Bin Zhang, Tristan Barbier, Carmelo Prestipino, et al.. Structure Low Dimensionality and Lone-Pair Stereochemical Activity: the Key to Low Thermal Conductivity in the Pb–Sn–S System. Journal of the American Chemical Society, 2024, ⟨10.1021/jacs.4c02893⟩. ⟨hal-04571271⟩
0 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More