Visible photoluminescence in ion beam mixed SiO2/Si/SiO2 layers

Abstract

Visible photoluminescence from silicon nanocrystals embedded in SiO₂ matrix by ion beam mixing was investigated. Photoluminescence spectra of ion beam mixed SiO₂/Si/SiO₂ films excited by an Ar-laser (457.9 nm) showed more intense luminescence with a peak centered at 720 nm than that prepared by the conventional ion implantation method. The formation of nanocrystals in SiO₂ matrix was confirmed by cross-sectional high resolution transmission electron microscopy. The red luminescence is attributed to the silicon nanocrystals produced by ion beam mixing.