Moreno Pastor, José AntonioGarrido Fernández, BlasPellegrino, PaoloGarcía Favrot, CristinaArbiol i Cobos, JordiMorante i Lleonart, Joan RamonMarie, P.Gourbilleau, FabriceRizk, Richard2012-05-032012-05-032005-07-080021-8979https://hdl.handle.net/2445/24864he complex refractive index of SiO2 layers containing Si nanoclusters (Si-nc) has been measured by spectroscopic ellipsometry in the range from 1.5 to 5.0 eV. It has been correlated with the amount of Si excess accurately measured by x-ray photoelectron spectroscopy and the nanocluster size determined by energy-filtered transmission electron microscopy. The Si-nc embedded in SiO2 have been produced by a fourfold Si+ ion implantation, providing uniform Si excess aimed at a reliable ellipsometric modeling. The complex refractive index of the Si-nc phase has been calculated by the application of the Bruggeman effective-medium approximation to the composite media. The characteristic resonances of the refractive index and extinction coefficient of bulk Si vanish out in Si-nc. In agreement with theoretical simulations, a significant reduction of the refractive index of Si-nc is observed, in comparison with bulk and amorphous silicon. The knowledge of the optical properties of these composite layers is crucial for the realization of Si-based waveguides and light-emitting devices.4 p.application/pdfeng(c) American Institute of Physics, 1984Propietats òptiquesMatèria condensadaEspectroscòpiaCristal·lografiaOptical propertiesCondensed matterSpectrum analysisCrystallographyinfo:eu-repo/semantics/article527385info:eu-repo/semantics/openAccess