First principles calculation of the thermal conductance of GaN/Si and GaN/SiC interfaces as functions of the interface conditions

First principles calculation and a statistical model are employed to calculate the thermal conductance (TC) of the interfaces GaN/Si and GaN/SiC. For an interface with zero tangential correlation length (L), TC of both GaN/Si and GaN/SiC increases with increasing the interface roughness. For an infinite L, TC of GaN/Si is almost insensitive to the roughness, while TC of GaN/SiC decreases rapidly with increasing the interface roughness. Generally speaking, for L=0, TC increases with increasing the interface roughness, whereas, for L=∞ the effect of the interface roughness on the interface TC depends on the phonon characteristics of the materials in contact.