This work deals with the modeling and simulation of quantum well lasers based on a heterostructure formed by indium gallium antimonide (InGaSb) and gallium antimonide (GaSb). The objective is to study the feasibility of a laser operating continuously in the near infrared for applications in the detection of polluting gases. Important device parameters such as the optical gain and threshold current density are investigated in detail. The results show that the optical gain is close to 4000 cm−1 and tends to increase with the carrier density in the active region but decreases with temperature and the quantum well thickness. The dependence of the laser threshold current density on the optical losses and temperature is also evaluated.

In this work, we modeled and simulated aZn(x)Cd(1-x)Te/ZnTe based single quantum well structure. We have taken into account the effect of carrier density, alloy composition, temperature and wells width on the optical gain as well as threshold current density. The use of ZnTe as a barrier leads to the improvement of the carrier confinement such as Q(c) (83%)/Q(v) (17%). Then, we have optimized the quantum well structure that allows obtaining a threshold current density Jth = 500A/cm(2). This study allowed us to achieve laser diodes VCSEL quantum well reliable and emitting around 0.740 mu m. (C) 2017 Elsevier GmbH. All rights reserved.

Amongst the interests in fuel cells is exploring the possibility of using different fuel types; one of them is biogas or Landfill gas (LFG) from landfills or from controlled digesters. Biogas; a gas produced by an anaerobic digestion of organic waste represents an environmental problem that could turn to a renewable energy source. The valorization of biogas into energy (electricity, heat, fuel) will save other sources of energy. The authors of the study are interested in evaluating three technologies: fuel cells, micro turbines and internal combustion engine.In this paper, we discussed the conversion of biomass into electricity in two steps: the first step (biomass-to-biogas) is based on an evaluation of biogas potential generated by solid waste of landfill the Batna city (Algeria) by the kinetic model (U.S.EPA, 1993). In the second step (biogas-to-electricity), the paper considers the technology of a stack of standard solid oxide fuel cells (Ni-YSZ/YSZ/LSM) SOFC; this allowed us to determine the best temperature, hydrogen concentration and electrolyte thickness for maximum power density in the fuel cell SOFC. At a temperature T = 1273 K and thickness of electrolyte of the order of 0.1 mm and at higher hydrogen concentration, a maximum power density of P = 1.4 W/cm(2) was obtained. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

The effects of direct internal reforming in a fuel cell solid oxide (SOFC) on thermal fields are studied by mathematical modeling. This study presents the thermal fields of a standard fuel cell (Ni-YSZ/YSZ/LSM) anode supported. This study is also made in the perpendicular plane at the flow of gases. The fuel cell is powered by air and fuel, CH4, H2, CO2, CO and H2O hence the birth of the phenomenon of direct internal reforming (DIR-SOFC). It is based on reforming chemical reactions, steam reforming reaction and water–gas shift reaction. The main purpose of this work is the visualization of temperature fields under the influence of global chemical reactions and the confirmation of the thermal behavior of this chemical reaction. The thermal fields are obtained by a computer program (FORTRAN).