Resonant bonding leads to low lattice thermal conductivity.
Understanding the lattice dynamics and low thermal conductivities of IV-VI, V2-VI3 and V materials is critical to the development of better thermoelectric and phase-change materials. Here we provide a link between chemical bonding and low thermal conductivity. Our first-principles calculations reveal that long-ranged interaction along the 〈100〉 direction of the rocksalt structure exist in lead chalcogenides, SnTe, Bi2Te3, Bi and Sb due to the resonant bonding that is common to all of them. This long-ranged interaction in lead chalcogenides and SnTe cause optical phonon softening, strong anharmonic scattering and large phase space for three-phonon scattering processes, which explain why rocksalt IV-VI compounds have much lower thermal conductivities than zincblende III-V compounds. The new insights on the relationship between resonant bonding and low thermal conductivity will help in the development of better thermoelectric and phase change materials.
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Sangyeop
S
Lee
1] Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, New Jersey 08901, USA [2] Institute for Advanced Materials and Devices for Nanotechnology (IAMDN), Rutgers University, Piscataway, New Jersey 08854, USA.
Keivan
K
Esfarjani
Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA.
Tengfei
T
Luo
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Jiawei
J
Zhou
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Zhiting
Z
Tian
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Gang
G
Chen