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The principal objective of this work based on modeling and simulation is to study the transport properties of Ga1-xInxAs1-y-zNySbz /GaAs structure. This investigation also contains the temperature effect on the electrons and holes mobility as a function of carrier concentrations. The obtained results were validated by experimental data. We started this work by simulating the ternary and quaternary electrons and holes mobilities. In this study, we find that an alloy structure with In = 38%, N = 2% and Sb = 1% has the best mobilities, for electrons μn = 104cm2/V.s and for holes μp = 400 cm2 /V. s at 300K. This work gives the ability to manufacture fast materials in order to realize high speed laser diodes as well as optoelectronic components. [ABSTRACT FROM AUTHOR]

The waste water rejected by the textile industries is loaded with organic dyes, responsible for the high color present in the effluents. Some dyes and / or their degradation products could be carcinogenic and may have mutagenic properties. The rapid growth of the global economy has caused many environmental problems with a huge pollution problem. The abuse use of chemicals product is an environmental toxicological problem. The consequences can be serious for water resources. In this perspective, our study comes to participate with new means of depollution using new materials with interesting properties in the treatment of pollution. Among these materials, LDHs whose synthesis is easy and inexpensive can be a tool in the treatment of water Polluted [1]. Our contribution consists in using HDL as a means of sorption of dyes which are considered as polluting agents of waters especially for the industry textile. This study considers the removal of the Alizarine Red S (AR) from water on calcined MgAl, ZnAL and MgZnAL-layered double hydroxides. The different LDH was prepared by copreprecipation method. The materials was obtained for molar ratios R =2 for the different LDH. The carbonated layered Calcination of these solids leads to the formation of mixed oxides which have the property of being able to be regenerated by adsorbing new anionic entities. Adsorbents and adsorption products were characterized by physicochemical techniques. The structural characterization of the material was carried out by X-ray diffraction, infrared spectroscopy (FTIR). Dosages of the polluted solutions were monitored by UV-Visible spectrometry. [ABSTRACT FROM AUTHOR]

Currently, quantum dots have attracted attention in the field of optoelectronics, and are used to overcome the limits of a conventional solar cell. Here, an In0.25Ga0.75N/GaN Quantum Dots Solar Cell has been modeled and simulated using Silvaco Atlas. Our results show that the short circuit current increases with the insertion of the InGaN quantum dots inside the intrinsic region of a GaN pin solar cell. In contrary, the open circuit voltage decreases. A relative optimization of the conversion efficiency of 54.77% was achieved comparing a 5-layers In0.25Ga0.75N/GaN quantum dots with pin solar cell. The conversion efficiency begins to decline beyond 5-layers quantum dots introduced. Indium composition of 10% improves relatively the efficiency about 42.58% and a temperature of 285 K gives better conversion efficiency of 13.14%. [ABSTRACT FROM AUTHOR]