Photoluminescent spectrum and dynamics of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">Si</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>-ion-implanted and thermally annealed<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">SiO</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>glasses

We have experimentally studied the photoluminescent (PL) properties of Si clusters in fused silica matrices. Si clusters in the ${\mathrm{SiO}}_{2}$ matrices were fabricated by ${\mathrm{Si}}^{+}$-ion implantation (200 keV, 2\ifmmode\times\else\texttimes\fi{}${10}^{17}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$) into silica and then thermally annealed in forming gas. A broad PL peak is observed in the visible spectral region at room temperature. The temperature dependence of the luminescent spectrum and the PL decay dynamics are controlled by nonradiative recombination processes due to phonon-assisted tunneling between localized radiative and nonradiative centers. Resonantly excited PL spectra indicate that the strong coupling of excitons and stretching vibrations of the Si-O bonds cause fine structures in the luminescent spectra. It is concluded that the interaction between electronic and vibrational excitations control the luminescent emission and the observed dynamics. \textcopyright{} 1996 The American Physical Society.