Ultralow and anisotropic thermal conductivity in semiconductor As2Se3

Author(s)

Gonzalez-Romero, Robert L. ^{[1, 2, 3]} ; Antonelli, Alex ^{[1, 2]} ; Chaves, Anderson S. ^{[1, 2]} ; Melendez, Juan J. ^{[4, 5]}

Affiliation

^[1] Univ Estadual Campinas, Inst Fis Gleb Wataghin, Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Ctr Computat Engn & Sci, Campinas, SP - Brazil

^[3] Univ Pablo Olavide, Dept Sistemas Fis Quim & Nat, Seville - Spain

^[4] Univ Extremadura, Dept Fis, Avda Elvas S-N, Badajoz 06007 - Spain

^[5] Inst Computac Cient Avanzada Extremadura ICCAEx, Badajoz - Spain

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 20, n. 3, p. 1809-1816, JAN 21 2018.
• Web of Science Citations: 5

Abstract

An ultralow lattice thermal conductivity of 0.14 W m(-1) K-1 along the ( b) over right arrow axis of As2Se3 single crystals was obtained at 300 K using first-principles calculations involving density functional theory and the resolution of the Boltzmann transport equation. This ultralow lattice thermal conductivity arises from the combination of two mechanisms: (1) a cascade-like fall of the low-lying optical modes, which results in avoided crossings of these with the acoustic modes, low sound velocities and increased scattering rates of the acoustic phonons; and (2) the repulsion between the lone-pair electrons of the As cations and the valence p orbitals of the Se anions, which leads to an increase in the anharmonicity of the bonds. The physical origins of these mechanisms lie in the nature of the chemical bonding in the material and its strong anisotropy. These results, whose validity has been addressed by comparison with SnSe, for which excellent agreement between the theoretical predictions and the experiments is achieved, point out that As2Se3 could exhibit improved thermoelectric properties. (AU)

• FAPESP's process: 15/26434-2 - Study of the electronic, structural, and transport properties of materials for thermoelectric applications via ab initio calculations
• Grantee: Anderson Silva Chaves
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 13/14065-7 - A first-principles study of electronic, structural, and transport properties of clathrates for thermoelectric applications
• Grantee: Robert Luis González Romero
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 13/08293-7 - CCES - Center for Computational Engineering and Sciences
• Grantee: Munir Salomao Skaf
• Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC