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1 – 3 of 3Rawad Elias, Pierre Ziade and Roland Habchi
The purpose of this paper is to investigate and classify the defects on silicon-based power devices under extreme conditions.
Abstract
Purpose
The purpose of this paper is to investigate and classify the defects on silicon-based power devices under extreme conditions.
Design/methodology/approach
Electrical characterization was performed on MOS devices to study their interface defects. The devices were subjected to a voltage or a current constraint to induce defects, and then measurements were done to detect the effects of those defects. Measurements include current voltage, capacitance and conductance characterization. The Hill–Coleman method was used to calculate the interface states density in each case.
Findings
It was found that most of the defects have energies within the upper band gap of the semiconductor.
Originality value
The method used in this paper allows the determination of any interface defects on a Si/SiO2 structure.
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Keywords
Abir Nachawaty, Maria Bassil, Antoine Choueiry, Mario Tahchi and Roland Habchi
Lightweight insulators are of major importance for the industry, in particular for thermal insulation in buildings. The purpose of this paper is to present a low-cost method to…
Abstract
Purpose
Lightweight insulators are of major importance for the industry, in particular for thermal insulation in buildings. The purpose of this paper is to present a low-cost method to obtain aerogels with high insulating properties.
Design/methodology/approach
Silica aerogel structures have been obtained by a low-cost sol-gel synthesis method. Surface modification, using dimethyldichlorosilane and trimethylchlorosilane, has been applied in order to get different thermal and optical properties.
Findings
The samples show very promising thermal properties as tested through an infrared camera observation. A 5-mm-thick piece of aerogel is able to withstand the temperature of a brazing flame and reduce the heat by at least 150 degrees on its opposite side. The samples have a vitreous like structure as observed by SEM, some surface cracking is observed but they stay within acceptable limits.
Originality/value
A very good thermal insulator is obtained with a very simple and low-cost method. The bulkiness of the supercritical drying is eliminated and the obtained structure has good properties.
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Jihad Sidawi, Carine Zaraket, Roland Habchi, Nathalie Bassil, Chafic Salame, Michel Aillerie and Jean-Pierre Charles
The purpose of this paper is to investigate the dark properties as a function of reverse current induced defects. Dark characteristics of solar modules are very essential in the…
Abstract
Purpose
The purpose of this paper is to investigate the dark properties as a function of reverse current induced defects. Dark characteristics of solar modules are very essential in the understanding the functioning of these devices.
Design/methodology/approach
Reverse currents were applied on the photovoltaic (PV) modules to create defects. At several time intervals, dark characteristics along with surface temperature were measured.
Findings
Current-voltage (I-V) and capacitance-voltage (C-V) characteristics furnished valuable data and threshold values for reverse currents. Maximum module surface temperatures were directly related to each of the induced reverse currents and to the amount of leakage current. Microstructural damages, in the form of hot spots and overheating, are linked to reverse current effects. Experimental evidence showed that different levels of reverse currents are a major degrading factor of the performance of solar cells and modules.
Originality/value
These results give a reliable method to predict most of the essential characteristics of a silicon solar cell or a module. Similar test could help predict the amount of degradation or even the failure of PV modules.
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