Emissive erbium-doped silicon and germanium oxide nanofibers derived from an electrospinning process

Use of sol-gel condensation reactions with the proper precursors, in conjunction with electrospinning methods, leads to the facile formation of one-dimensional nanofibers of silicon or germanium dioxide doped with erbium. These nanowires are characterized by a combination of scanning and transmission electron microscopies, energy dispersive X-ray analysis, FT IR spectroscopy, X-ray diffraction, and photoluminescence spectroscopy. By comparing such structures with comparably sized nanofibers of erbium oxide (Er ₂O₃), the influence of oxide matrix and erbium concentration on Er³⁺ luminescence in the near-infrared at 1540 nm is examined. Furthermore, an analysis of the luminescence excitation spectra of Er-doped GeO₂ nanofibers prepared by the above route with Er-doped GeO₂ NWs and Er-doped Ge NWs prepared by a different vapor-liquid-solid pathway suggests a common excitation mechanism of erbium ions in these structures assisted by GeO_x through a carrier-mediated process.