In this research TiO 2 , SnO 2 and TiO 2 :SnO 2 nanocomposite thin films were fabricated by the sol-gel dip coating technique. The mixture was prepared by varying the molar ratio of SnO 2 to TiO 2 , i.e. TiO 2 :SnO 2 (9:1), TiO 2 :SnO 2 (8:2) and TiO 2 :SnO 2 (6:4)). The obtained samples were characterized by means of the Raman microscopy, Scanning Electron Microscopy (SEM), UV-Vis spectrophotometry and m-lines spectroscopy (Prism coupler). Raman analysis shows that pure TiO 2 and SnO 2 thin films are characterized by the vibrational modes of anatase and rutile cassiterite, respectively. Furthermore, the Raman spectra of the TiO 2 :SnO 2 nanocomposites show the presence of a mixture of anatase and rutile TiO 2 phases. The SEM images reveal that the morphology is clearly modified with SnO 2 content. The ripples in the transmittance spectra decreased with increasing SnO 2 content. Also, the evolution of the optical band gap seems to be consistent with the Raman analysis. A great attention has been paid to the refractive index measurements by the prism coupler technique. In this way, variable-refractive index systems have been successfully obtained using TiO 2 :SnO 2 nanocomposite thin films.

No abstract

Polycrystalline zinc oxide (ZnO) thin films have been deposited at 450˚C onto glass and silicon substrates by pulsed laser deposition technique (PLD). The used source was a KrF excimer laser (248 nm, 25 ns, 5 Hz, 2 J/cm 2 ). The effects of glass and silicon substrates on structural and optical properties of ZnO films have been investigated. X-ray diffraction patterns showed that ZnO films are polycrystalline with a hexagonal wurtzite-type structure with a strong (103) orientation and have a good crystallinity on monocrystalline Si(100) substrate. The thickness and compositional depth profile were studied by Rutherford Backscattering spectrometry (RBS). The average transmittance of ZnO films deposited on glass substrate in the visible range is 70%.

No abstract

No abstract

No abstract

No abstract

No abstract