OPTICAL-PROPERTIES OF PECVD ERBIUM-DOPED SILICON-RICH SILICA - EVIDENCE FOR ENERGY-TRANSFER BETWEEN SILICON MICROCLUSTERS AND ERBIUM IONS

We report the fabrication by PECVD of silicon-rich erbium-doped silica films that exhibit both 1535 nm fluorescence and visible photolumines cence. Fluorescence spectra are presented along with absorption spectr a that display a strong band edge in die blue, which we ascribe to the presence of Si microclusters. We are unable to observe characteristic Er3+ absorption bands and propose that excitation of the rare earth i s via an energy transfer process from Si microclusters.