Visible light emission from Si nanocrystalline composites via reactive evaporation of SiO

Amorphous SiOx layers with adjustable oxygen content have been deposited on to Si wafers by thermal evaporation of SiO in controlled O-2 atmosphere. Th e oxygen content of the deposited films was determined from Rutherford back scattering analysis. Decomposition of the SiOx at 1000 degreesC yields well established Si nanocrystallites in an SiO2 matrix as shown by high resolut ion transmission electron microscopy (HRTEM). Nanocrystallites formed upon annealing at 1000 degreesC show intense photoluminescence (PL) in the visib le to near infrared spectral range. The correlation of the initial oxygen c ontent of the layer with the crystallite size and PL properties is analyzed . The observed shift in PL-peak emission from 880 down to 750 nm can be exp lained by the formation of smaller crystallites during annealing as a resul t of increasing oxygen content. (C) 2001 Elsevier Science B.V. All rights r eserved.