Size and edge roughness dependence of thermal conductivity for vacancy-defective graphene ribbons.
By incorporating the phonon-phonon scattering, phonon-boundary scattering and phonon-vacancy scattering into the linearized Boltzmann transport equation, we theoretically investigate the effects of size and edge roughness on thermal conductivity of single vacancy-defective graphene ribbons. Due to the severe suppression of high-frequency phonons by phonon-vacancy scattering which includes the impacts of missing mass and linkages, as well as the variation of the force constant of bonds associated with vacancies, the low-frequency ballistic phonons have a higher contribution to the thermal conductivity, which results in the stronger length, weaker width and weaker edge roughness dependence on thermal conductivity of vacancy-defective graphene ribbons than that of pristine ones. Our findings are helpful to understand and manipulate thermal conductivity of graphene by phononic engineering.
Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronics, Xiangtan University, Hunan 411105, P. R. China. gfxie@xtu.edu.cn.
Guofeng
G
Xie
Yulu
Y
Shen