title: A bond-order theory on the phonon scattering by vacancies in two-dimensional materials.
abstract: We theoretically investigate the phonon scattering by vacancies, including the impacts of missing mass and linkages (τ(V)(-1)) and the variation of the force constant of bonds associated with vacancies (τ(A)(-1)) by the bond-order-length-strength correlation mechanism. We find that in bulk crystals, the phonon scattering rate due to change of force constant τ(A)(-1) is about three orders of magnitude lower than that due to missing mass and linkages τ(V)(-1). In contrast to the negligible τ(A)(-1) in bulk materials, τ(A)(-1) in two-dimensional materials can be 3-10 folds larger than τ(V)(-1). Incorporating this phonon scattering mechanism to the Boltzmann transport equation derives that the thermal conductivity of vacancy defective graphene is severely reduced even for very low vacancy density. High-frequency phonon contribution to thermal conductivity reduces substantially. Our findings are helpful not only to understand the severe suppression of thermal conductivity by vacancies, but also to manipulate thermal conductivity in two-dimensional materials by phononic engineering.
authors.affiliation: Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Faculty of Materials, Optoelectronics and Physics, Xiangtan University, Hunan 411105, P.R. China.
authors.forename: Guofeng
authors.initials: G
authors.lastname: Xie
authors.affiliation: Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Faculty of Materials, Optoelectronics and Physics, Xiangtan University, Hunan 411105, P.R. China.
authors.forename: Yulu
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Faculty of Materials, Optoelectronics and Physics, Xiangtan University, Hunan 411105, P.R. China.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Wei
authors.affiliation: Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Faculty of Materials, Optoelectronics and Physics, Xiangtan University, Hunan 411105, P.R. China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Yang
authors.affiliation: Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Faculty of Materials, Optoelectronics and Physics, Xiangtan University, Hunan 411105, P.R. China.
authors.forename: Huaping
authors.initials: H
authors.lastname: Xiao
authors.affiliation: Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Faculty of Materials, Optoelectronics and Physics, Xiangtan University, Hunan 411105, P.R. China.
authors.forename: Jianxin
authors.initials: J
authors.lastname: Zhong
authors.affiliation: Institute of High Performance Computing, Singapore 138632, Singapore.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhang