I.C. Vasiliu,  M. Gartner, M. Anastasescu, L. Todan, L. Predoana, M. Elisa, C. Grigorescu, C. Negrila, C. Logofatu, M. Enculescu, A. Moldovan, G. Pavelescu, M. Zaharescu, SiOx–P2O5 films—promising components in photonic structures, Opt. Quant. Electron., 39 (2007) 511–521

Title: SiOx–P2O5 films—promising components in photonic structures

Abstract: We intend to prepare periodic multilayered structures for photonic applications. With this goal we have performed a study of some characteristics of SiO (x) -P2O5 films deposited by the sol-gel method on glass and ITO (InSnO (x) )-coated glass. The as prepared films were annealed to different temperatures (150 and 200 degrees C). The chemical composition of the samples was determined by X-ray Photoelectron Spectroscopy (XPS). The XPS results revealed the presence of P in the as-deposited films. The structural an optical properties were examined by Fourier Transform Infrared Spectroscopy (FTIR), Spectroellipsometry (SE) and UV Transmission Spectroscopy. IR spectra of the deposited films attest the interaction of an amorphous SiO2 with the H3PO4 used as a P-precursor. Refractive indices for individual SiO (x) -P2O5 determined from SE measurements show a densification of the layer structure with the increasing temperature in the thermal treatment. The UV transmission spectra revealed a lower transmission for the sol-gel SiO (x) -P2O5 films as compared to ITO/glass substrate. AFM images proved the densification of the films with annealing in agreement with the ellipsometric results.

Key words: phosphorous silicate films; Sol-gel; ellipsometry; XPS; AFM; UV-VIS