Y. Kanemitsu et al., PHOTOLUMINESCENT SPECTRUM AND DYNAMICS OF SI-ION-IMPLANTED AND THERMALLY ANNEALED SIO2 GLASSES(), Physical review. B, Condensed matter, 54(20), 1996, pp. 14329-14332
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.