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This work aims to find a relation between both indium and nitrogen concentrations in InGaAsN and the impulse response on one hand and the depletion region thickness with the impulse response on the other hand. In the present we adopt a new structure with strained quantum well based on double transparent regions p-side and n-side. The impulse response is calculated after fixing indium and nitrogen fractions (x=31.5 %, y=0.2 %) and (x=6.5%, y=2.05 %) with strain E=0.5% and −0.132% respectively having definite bandgap energy parameter

In this present work, the aim is to evaluate the effect of different times of ultrasound pretreatment prior to hydrodistillation (US-HD) on the yield, chemical composition and antioxidant activity of essential oils of two wild Lavandula stoechas L. from the North of Algeria. The results indicate that ultrasound treatment engenders a rapid release of essential oils (1.59 %) recovery after only 10 min of sample of Adekar treated by ultrasound and followed by 90 min of hydrodistillation (HD) versus 180 min of hydrodistillation of untreated sample (1.17 %). However, the yields of Keddara sample treated by 45 min versus untreated samples were 0.87 % versus 0.62 %. 94.30 % and 88.26 % of total compounds were identified using chromatographymass spectrometry (GC-MS) in samples of Adekar and Keddara treated by ultrasound versus untreated samples (92.64 % and 88.75 % respectively). A difference in chemical composition between the essential oils of the two harvesting sites and between the extracts obtained by HD and by US-HD was found. The percentage of the most of the major compounds (fenchone, camphor, 1,8-cineole, bornyl-acetate, myrtenyl-acetate and viridiflorol) and other compounds identified is higher in treated L. stoechas L. than untreated L. stoechas L. The study of antioxidant power was carried out by 2, 2 diphenyl-1-picrylhydrazyl (DPPH) method. The results showed that antioxidant power of treated samples is superior to antioxidant power of untreated samples. Antioxidant activity of both samples (treated and untreated) is less effective compared with antioxidant activity of ascorbic acid.

In this work, a numerical simulation is used to explore and determine the arsenic content profile and effects of the well thickness on the intersubband coefficient of the conduction band in the GaAs x P 1-x /GaP quantum well structure, x is the concentration of arsenic. This theoretical study has shown that the intersubband conduction band and the corresponding wavelength emission are mainly affected by these both factors. Hence, one should adjust the desired energy and achieve a large absorption coefficient by changes the quantum well width and the arsenic composition.

In this paper we study the effects of In concentration, temperature, quantum well width and carrier density on optical gain for GaSb/InxGa1-xSb/GaSb untrained quantum well structures. This system was chosen as it is useful in infrared emission, finally, we introduce the optimum structure of quantum well to obtain the maximum optical gain, at room temperature and infrared emission particularly 2.3 (μm), for the use this structure in application of spectroscopic analysis of the gases specially CH4. This structure can be used for light absorption to increase the solar cell efficiency a based on a quantum well and multi-junction.