Abstrait

Morphology and Optical Properties of SiO2 Embedded in Porous Alumina Matrix (Al2O3) Deposited on Transparent Polypropylene (TPP) Leaf: For Reflective Surfaces

Mondher G, Ouartani R, Ezzaouia H

In this work, Silicon oxide (SiO2) is deposited in a porous alumina matrix (PAM) on transparent polypropylene (TPP) leaf, by a radio frequency plasma enhanced chemical vapor deposition PECVD method. The morphological and microstructural property of (SiO2/PAM/TPP) structure is investigated by TEM, EDX, XRD technique and Raman spectroscopy. Crystallization of the amorphous SiO2/PAM/TPP is obtained after deposition at was 650°C at different deposition time ranging from 20 to 60 min. The effect of deposition on the optical properties of SiO2/PAM/TPP structure was studied by Spectroscopic Ellipsometry (SE) in the spectral range 0.3-0.8 μm. The Ellipsometric analysis demonstrated the formation of mixture layers with SiO2 diffused in porous alumina barrier layer different deposition time. The optical constants, thickness and the composition of each film have been estimated from the SE data using Bruggeman effective medium approximation. PL spectroscopy was used to investigate the band gap energy of SiO2/PAM, the origin of emission PL spectra as well as the observed red-shift have been discussed, this observation has been confirmed with reflectivity measurements. As a consequence the reflectivity reaches 99% when SiO2/PAM/TPP films obtained were SiO2 deposed at 50 min.