International audienceThis paper reports on the micro-instrumented indentation of a porous silicon structure obtained by anodization of a highly p(+)-doped (100) silicon substrate aged over 1 week. The three-layer structure obtained consists of oxidized porous silicon (cap-layer), porous silicon (inner-layer) and silicon substrate. The hardness curve has the typical "U shape" of low-dielectric-constant films when the indentation depth rises: the early decrease in hardness, due to the soft inner layer, is followed by an increase, due to the hard substrate. A multilayer model is developed to account for hardness variation with respect to the applied load. This model considers the crumbling of the cap-layer and of the inner porous structure. As a result, it is shown that considering the minima in the U shape gives an over-estimated value when it comes to assessing the coating hardness. in our experiment, this minimum depends on both the hardness and the thickness of the but not on the mechanical properties of the substrate, even for indentation depths slightly oxidized cap layer, lower than the film's thickness. (C) 2009 Elsevier B.V. All rights reserved

In this work, we studied with a Matlab program, some of optical properties of zinc oxide (ZnO) deposited on glass (SiO2). The parameters studied include the refraction index, extinction coefficient, optical band gap, and complex dielectric constant versus incident photon energy, and transmittance, absorbance and reflectance spectrum of ZnO thin film deposited on glass (SiO2) for different thickness. The films were found to exhibit high transmittance (75-95%), low absorbance and low reflectance in the visible / near infrared region up to 1000 nm. However, the absorbance of the films was found to be high in the ultra violet region with peak around 380 nm.

The total energy balance sheet of Algeria in the year 2009 shows that the final energy consumption is evaluated as 30.98 million TEP (Ton oil equivalent) and emphasizes a prevalence of energy consumption in the household sector as more than 41% compared with 19% from the industry sector and 33% from transport. In this article, an analysis of the use of the various energy vectors in an individual dwelling (conventional and ecological house) in urban environment is presented. The thermal parameters influencing the building are evaluated, illustrating the potential for energy losses, as well as energy gains for both types of buildings. The results are compared to demonstrate the requirement to use more ecological materials for buildings to realize savings in energy and economic terms to reduce heating and cooling and to minimize emissions of CO 2 , for a more carbon-efficient-sustainable built environment.

ZnO is an important II-VI semiconductor material for devices with possible applications such as piezoelectric transducers, gas sensors, transparent electronic in solar cell, saw devices. Based on known research, ZnO is the most promising in optoelectronic and optical applications, especially in UV region. An understanding of the optical properties of ZnO thin film on different substrates is also needed to obtain the optimal configuration for the best performance. In this work, we start our simulation by made a Matlab code to study the Sellmeier equation. The behavior of light transmission of ZnO/BK7 glass and ZnO/Sapphire is studied. Both the variation of thickness of ZnO film and different parameters of Sellmeier model are studied. This approach helps us to determine the best configuration (thin film / substrate) to made advices for optoelectronic applications.

No abstract