A. L. Moore, Saha, S. K., Prasher, R. S., and Shi, L., “Phonon Backscattering and Thermal Conductivity Suppression in Sawtooth Nanowires,” Appl. Phys. Lett., vol. 93, pp. 083112, 2008.
The effect of surface roughness on phonon transport in a nanowire has often been described by treating the surface as flat with a specularity parameter (p) in the range between 0 and 1. A lower thermal conductivity limit is approached at p=0 for diffuse surface. It is demonstrated here by Monte Carlo simulation that sawtooth roughness on a nanowire can cause phononbackscattering and suppress the thermal conductivity below the diffuse surface limit. The backscattering effect can be accounted for only by a negative p if the detail of the surface roughness is ignored.