PHOTOLUMINESCENT SPECTRUM AND DYNAMICS OF SI-ION-IMPLANTED AND THERMALLY ANNEALED SIO2 GLASSES()

We have experimentally studied the photoluminescent (PL) properties of Si clusters in fused silica matrices. Si clusters in the SiO2 matrice s were fabricated by Si+-ion implantation (200 keV, 2x10(17) cm(-2)) i nto silica and then thermally annealed in forming gas. A broad PL peak is observed in the visible spectral region at room temperature. The t emperature dependence of the luminescent spectrum and the PL decay dyn amics are controlled by nonradiative recombination processes due to ph onon-assisted tunneling between localized radiative and nonradiative c enters. Resonantly excited PL spectra indicate that the strong couplin g of excitons and stretching vibrations of the Si-O bonds cause fine s tructures in the luminescent spectra. It is concluded that the interac tion between electronic and vibrational excitations control the lumine scent emission and the observed dynamics.