Exciton-erbium coupling in SiOx suboxide films prepared by combining sol-gel chemistry and ion implantation

The efficiencies of three methods based on a combination of sol-gel chemistry and ion implantation for obtaining an optical activation of Er atoms via the transfer of excitons energy are compared. A better coupling is observed in silica-gel containing Er prepared by addition of Er nitrate to the tetraethoxysilane sol and embedding Si nanocrystals formed by ion implantation or in a silicon suboxide derived from triethoxysilane and implanted with Er ions than in silica-gel implanted sequentially with Si then Er. The infrared emission of Er ions is reduced by the segregation of erbium oxide or the precipitation of Er5Si3, depending on the matrix, in films containing more than 1 at.% Er annealed at temperatures over 1000 degreesC. (C) 2002 Elsevier Science B.V. All rights reserved.