Novel Er-doped SiC/SiO2 nanocomposites: Synthesis via polymer pyrolysis and their optical characterization

Erbium activated SiC/SiO2 nanocomposites doped with Er3+ concentrations ranging from 1 to 4 mol% were prepared by pyrolysis of sol–gel derived precursors. The gels were obtained from modified silicon alkoxides containing Si–CH3 and Si–H groups. Thin discs obtained from the monolithic xerogels were pyrolyzed in an alumina tubular furnace in flowing Ar (100 ml/min) at 800, 1000, 1200 and 1300 °C. The samples were investigated by absorption and photoluminescence spectroscopies. Emission in the C-telecommunication band was observed at room temperature for all the samples upon continuous-wave excitation at 980 or 514.5 nm. The shape of the emission band corresponding to the 4I13/2 → 4I15/2 transition is found to be independent both on Erbium content and excitation wavelength, with a Full Width Half Maximum (FWHM) of 48 nm. By increasing the pyrolysis temperature the intensity of the luminescence increases and the electronic bandgap energy decreases.