http://archives.univ-biskra.dz/handle/123456789/2167 Mon, 06 Apr 2026 17:43:43 GMT 2026-04-06T17:43:43Z 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 http://archives.univ-biskra.dz/handle/123456789/7361 Titre: Numerical simulation of bias and photo stress on indium-gallium-zinc-oxide thin film transistors Auteur(s): M. Adaika; Af Meftah; N. Sengouga; M. Henini Résumé: Thin Film Transistors based on amorphous Indium-Gallium-Zinc-Oxide (a-IGZO TFT) are receiving a great deal of attention for their numerous applications as alternatives for amorphous and poly-crystalline Silicon based TFTs. A major concern about a-IGZO TFTs is that they suffer from instabilities when subjected to different types of stress (bias, light, etc...). Stress is believed to create defects of different kinds in different regions of the device. The instability manifests as a shift in the threshold voltage or a hump in the transfer characteristics of the transistor. In addition, there is still a great deal of confusion about the relation between defects and the instability induced by stress. The main purpose of this study is to elucidate the relation between the threshold voltage shift (instability) and the defects created by stress. For this purpose a detailed numerical simulation was carried out to investigate the relation between the different types of defects created by stress and the induced instability in a-IGZO TFT. It was found that tail, deep and interface states cause a shift in threshold voltage. Negative and positive shifts are observed if the defects are donor-like and acceptor-like defects, respectively. On the other hand, a hump in the transfer characteristics is induced if discrete interface levels are dominant. Thu, 03 Mar 2016 00:00:00 GMT http://archives.univ-biskra.dz/handle/123456789/7361 2016-03-03T00:00:00Z