Confined Optical Phonon Scattering in p-Silicon Nanowires

In this paper, we investigate hole scattering by optical phonons through the deformation potential interaction, which is one of the main mechanisms for dissipation at room temperature. We consider free-standing cylindrical silicon nanowires of radius R, length L, and with the z-axis along the QWR direction (see Fig 1). We assume an infinite cylindrical well potential profile for the holes (i.e. V = 0 inside the wire and V = oo on the radial edges). In conclusion, we found considerably lower scattering rates for confined phonons than if calculated with a continuous phonon spectrum, especially at small radii. In addition, we showed confined phonons favor backward scattering over forward scattering in narrow QWRs. Our results have important consequences for the dissipation processes in nanowire based MOSFETs.