Thermal transmission at Si/Ge interface: ab initio lattice dynamics calculation

Eurotherm Seminar No 108 - Nanoscale and Microscale Heat Transfer V

Alkurdi, A.^1,2 ; Merabia, S.^1

Institut Lumière Matière, UMR5306, Université Claude Bernard Lyon 1, CNRS, Université de Lyon, Villeurbanne Cedex

69622, France^1

Department of Physics, Al-Baath University, Homs, Syria^2

关键词: Dynamics calculations;    Energy transmission;    Phonon frequencies;    Phonon transmissions;    Scattering direction;    Thermal boundary conductance;    Thermal transmission;    Transmission angle;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/785/1/012001/pdf
DOI  :  10.1088/1742-6596/785/1/012001

来源: IOP

【 摘 要 】

We perform lattice dynamics calculations (LD) on silicon/germanium interfaces using ab initio interatomic force constants to predict the interfacial phonon transmission as a function of both phonon frequency and the transmission angle. We carry out a spectral and angular analysis to quantify the contribution of each phonon mode in a given scattering direction. The effect of the interaction range was studied at this interface by taking account of more or less atom layers across the interface. Moreover, we were able to predict the thermal boundary conductance (TBC) as a function of the transmission angle and temperature as well. Our results show that, the thermal energy transmission is highly anisotropic while thermal energy reflection is almost isotropic. In addition, we found that it seems there is a global critical angle of transmission beyond which almost no thermal energy is transmitted. This can be used to device high pass phonon filter via changing the orientation of the interface.