Optical properties of interacting Si nanoclusters in SiO_2 fabricated by ion implantation and annealing

摘要

A novel method for the fabrication of luminescent Si nanoclusters in an amorphous SiO_2 matrix by ion implantation and annealing, and the detailed mechanisms for the photoluminescence from implanted Si nanoclusters are reported. We have measured dose (concentration of excess Si atoms), annealing time and excitation energy dependence of the pnhotoluminescence of Si nanoclusters in SiO_2 layers. The samples were fabricated by Si ion nanoclusters, for which the band-gap energy is modified by the quantum confinement effects, and the emission is not simply due to direct electron-hole recombination inside Si nanoclusters, but is related to defects probably at the interface between Si nanoclusters and SiO_2, for which the energy state is affected by Si cluster-cluster-cluster interactions. It seems that Si nanoclusters react via a thin oxide interface and the local concentrations of Si nanoclusters play an important role in the peak energy of the photoluminescence. direct c 1999 Published by Elsevier Science B.V. All rights reserved.