Simulation of Phonon Transmission at Semiconductor Interfaces Using an Atomistic Green’s Function Method
An atomistic Green’s function method is applied to study phonon transport across interfaces between two semi-infinite semiconductors. We investigate the dependence of phonon transmission function on interface atomic configuration, roughness layer thickness and phonon frequency. The transmission function is obtained for a number of interface configurations, including Si/Ge/Si confined structures and a single Si/Ge interface. An interface with a regularly-patterned roughness is investigated to illustrate how the rough interface influences phonon transmission. The results show that the cutoff frequency and the local density of states are modified due to the rough interface. The transmission function is found to strongly dependent on the presence of atomic-scale roughness.