Photoluminescence of Ge nanoclusters in ion implanted SiO2

180 nm thick SiO2 films produced by wet oxidation of (100) Si wafers were implanted at room temperature with 120 keV Ge+ ions at a fluence of 1.2X10(16) cm(-2) in order to allow the formation of Ge nanoparticles upon post implantation thermal annealings within the interval 400degreesC less than or equal to T less than or equal to 900degreesC. ne size and depth distribution of the Ge nanoparticles were characterized by Transmission Electron Microscopy and Rutherford Backscattering Spectrometry. In addition, the room temperature photoluminescence (PL) bands of the nanoparticles system were studied in the regions of the blue-violet and ultra-violet emissions. The mean diameter of the nanoclusters increases from 2.2 nm at 400degreesC to 5.6 nm at 900degreesC. Concomitantly, the blue-violet PL intensity increases by a factor of 12 within the same temperature interval, The results are discussed in terms of possible atomic mechanisms involved in the coarsening behavior and leading to the formation of luminescent centers.