Probing Mie scattering effects of Si-embedded Ge spherical QD arrays using Raman analysis

Abstract

We reported experimental observation of Mie scattering effects of Si embedded Ge quantum dot (QD) arrays. The interaction of Ge QDs with Si nanolayers is characterized by surface enhanced Raman scattering (SERS) of longitudinal optical (LO) Si phonons by the strong electromagnetic fields of Ge QDs. The Mie effect is further evidenced from µ-disk arrays of Si-embedded Ge QDs, in which enhanced optical emission and heightened SERS of optical Ge and LO-Si phonons occur at the disk's edge. Notably, the LO-Si intensity appears to be an effective signature of near-field optical coupling and radiative transfer between neighboring disks.