http://archives.univ-biskra.dz/handle/123456789/2166 Sun, 19 Apr 2026 16:27:16 GMT 2026-04-19T16:27:16Z http://archives.univ-biskra.dz:80/retrieve/49066/2.png http://archives.univ-biskra.dz/handle/123456789/2166 http://archives.univ-biskra.dz/handle/123456789/7365 Titre: Deep traps and temperature effects on the capacitance of p-type Si-doped GaAs Schottky diodes on (2 1 1) and (3 1 1) oriented GaAs substrates Auteur(s): R. Boumaraf; N. Sengouga; R.H. Mari; Af. Meftah; M. Aziz; Dler Jameel; Noor Al Saqri; D. Taylor; M. Henini Résumé: The SILVACO-TCAD numerical simulator is used to explain the effect of different types of deep levels on the temperature depen- dence of the capacitance of p-type Si-doped GaAs Schottky diodes grown on high index GaAs substrates, namely (3 1 1)A and (2 1 1)A oriented GaAs substrates. For the (3 1 1)A diodes, the measured capacitance–temperature characteristics at different reverse biases show a large peak while the (2 1 1)A devices display a much smaller one. This peak is related to the presence of different types of deep levels in the two structures. These deep levels are characterized by the Deep Level Transient Spectroscopy (DLTS) technique. In the (3 1 1)A structure only majority deep levels (hole deep levels) were observed while both majority and minority deep levels were pres- ent in the (2 1 1)A diodes. The simulation software, which calcu- lates the capacitance–voltage and the capacitance–temperature characteristics in the absence and presence of different types of deep levels, agrees well with the experimentally observed behavior of the capacitance–temperature properties. A further evidence to confirm that deep levels are responsible for the observed phenom- enon is provided by a simulation of the capacitance–temperature characteristics as a function of the ac-signal frequency. Thu, 03 Mar 2016 00:00:00 GMT http://archives.univ-biskra.dz/handle/123456789/7365 2016-03-03T00:00:00Z http://archives.univ-biskra.dz/handle/123456789/7364 Titre: Modeling the effect of defects on the performance of an n-CdO/p-Si solar cell Auteur(s): S. Chala; N. Sengouga; F. Yakuphanoglu Résumé: The interest in the study of Cadmium oxide (CdO) for photonic applications has increased significantly because of its promising electrical and optical properties. Real solar cells based on an n-CdO/p-Si heterostructures show poor photovoltaic performance, however. In this work numerical simulation is used to elucidate this poor performance by considering two cases. CdO is firstly considered as a perfect crystalline semiconductor. The second case models CdO as a semiconductor with continuous distribution of defects states in its band gap, similar to an amorphous semiconductor, made of two tail bands (a donor-like and an acceptor-like) and two Gaussian distribution deep level bands (an acceptor-like and a donor-like). Evidently the first case produced results far from reality. In the second case, however, and by adjusting the constituents of the band gap states the open circuit voltage (VOC) and the short circuit current (JSC) were almost perfectly reproduced but not the fill factor (FF) and the conversion efficiency (η). The p-type doping of Silicon adjustment has lead to a better reproduction of the two latter parameters. Thu, 03 Mar 2016 00:00:00 GMT http://archives.univ-biskra.dz/handle/123456789/7364 2016-03-03T00:00:00Z http://archives.univ-biskra.dz/handle/123456789/7363 Titre: Optimization of Optical Gain in Inx Ga1-xSb/GaSb unstrained quantum well structures Auteur(s): Said Dehimi; Aissat Abdelkader; Djamel Haddad; Lakhdar Dehimi Résumé: n 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. Thu, 03 Mar 2016 00:00:00 GMT http://archives.univ-biskra.dz/handle/123456789/7363 2016-03-03T00:00:00Z http://archives.univ-biskra.dz/handle/123456789/7362 Titre: SMALL-SIGNAL TIME-DOMAIN PHYSICAL/ELECTRICAL FET MODELING APPROACH Auteur(s): N.A. Abdeslam; S. Asadi; N. Sengouga; M.C.E. Yagoub Résumé: In this paper, a reliable small-signal time-domain FET modeling approach is proposed. Based on physical/electrical parameters, the proposed model can efficiently characterize high-frequency transistors. Thu, 03 Mar 2016 00:00:00 GMT http://archives.univ-biskra.dz/handle/123456789/7362 2016-03-03T00:00:00Z