Marseille, France
Marseille, France

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Tanay F.,French National Solar Energy Institute | Tanay F.,French Environment and Energy Management Agency | Dubois S.,French National Solar Energy Institute | Enjalbert N.,French National Solar Energy Institute | And 3 more authors.
Physica Status Solidi (C) Current Topics in Solid State Physics | Year: 2012

The light-induced degradation (LID) due to the boron-oxygen (B-O) complexes is particularly harmful for solar cells made from the boron-doped p -type Czochralski silicon (Cz-Si). Many studies focused on this phenomenon and some processes have been proposed to reduce it. Recently, Cz-Si voluntarily doped with germanium (Ge) was used to inhibit the effect of the B-O complexes activation. We studied here both conventional Cz-Si (CZ) and Ge-doped Cz-Si (GCZ), and compared their sensitivity to the LID. The first result was that solar cells produced with GCZ had the same performances than solar cells made with CZ despite the impurities like iron unintentionally introduced in GCZ by the Ge powder. Then, we found that the degradation under illumination of the efficiency was lower in GCZ only for the solar cells produced from the last solidified part of the ingot (where the Ge content is the highest). These differences were correlated with the amount of interstitial oxygen (O i) which was found to be lower for the GCZ wafer, possibly due to the formation of Ge-O i related defects and/or to Ge-enhanced oxygen precipitation effects. At the cell level, we also compared the kinetics of the LID in both materials and confirmed that the degradation was slower in GCZ. Finally, we showed that the mechanism of lightinduced regeneration (LIR) also occurs in GCZ solar cells, with similar kinetics with respect to conventional Cz-Si cells. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zalden P.,RWTH Aachen | Aquilanti G.,Elettra - Sincrotrone Trieste | Prestipino C.,CNRS Chemistry Institute of Rennes | Mathon O.,European Synchrotron Radiation Facility | And 3 more authors.
Journal of Synchrotron Radiation | Year: 2012

A Calvet-type differential scanning calorimeter has been implemented on a synchrotron beamline devoted to X-ray absorption spectroscopy. As a case study, the complex crystallization process in amorphous Ge 15Sb 85 phase-change material is followed by simultaneous calorimetric and quick-EXAFS measurements. A first crystallization at 514(1) K is related to the crystallization of an Sb-rich phase accompanied by segregation of Ge atoms. Upon further heating, the as-formed amorphous Ge regions crystallize at 604(1) K. A quantitative analysis of the latent heat allows a Ge 11Sb 89 stoichiometry to be proposed for the first crystallized phase. © 2012 International Union of Crystallography Printed in Singapore - all rights reserved.

Schutz-Kuchly T.,French National Solar Energy Institute | Dubois S.,French National Solar Energy Institute | Veirman J.,French National Solar Energy Institute | Veschetti Y.,French National Solar Energy Institute | And 2 more authors.
Physica Status Solidi (A) Applications and Materials Science | Year: 2011

This study focuses on the evolution under illumination of the electrical performances of solar cells made with n-type boron-phosphorus compensated Czochralski silicon. First, we show via carrier lifetime measurements that this material is sensitive to light-induced degradation (LID) effects due to the formation of BO i2 complexes. Solar cells were then processed with this compensated material. The cells performances were found to be dependent on the position of the wafer along the ingot height. This dependence is due to carrier lifetime variations along the ingot height and is not directly linked with the differences in concentration between boron and phosphorus. LID experiments were then performed on the same cells. Unlike what was suggested from previous studies, we highlighted a weak decrease of the cell performances under illumination, consistent with the electrical characterizations at the wafer level. These degradations have been quantified and linked with the chemical composition of the material. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tanay F.,French National Solar Energy Institute | Dubois S.,French National Solar Energy Institute | Enjalbert N.,French National Solar Energy Institute | Veirman J.,French National Solar Energy Institute | Perichaud I.,IM2NP
Energy Procedia | Year: 2013

The present study focuses on the kinetics of the boron-oxygen defect activation in solar cells fabricated from two Czochralski silicon ingots having different compositional properties (particularly various carbon and germanium contents). We show first that the difference between the experimental and the expected time constants associated with the degradation of the cells performances under illumination due to the boron-oxygen activation is higher in the last solidified part of the ingots. Secondly at such locations a pronounced slowing down of the long-term kinetics is observed. Possible explanations are proposed and discussed among which the segregation of some impurities which could interact with oxygen or oxygen dimers. Particularly a clear correlation is highlighted between the carbon content and the amplitude of this slowing down. Eventually this work shows that the experimental conditions generally used for evaluating the amplitude of the light-induced degradation effects have to be reconsidered. © 2013 The Authors.

Gailhanou H.,Bureau de Recherches Géologiques et Minières | Blanc P.,Bureau de Recherches Géologiques et Minières | Rogez J.,IM2NP | Mikaelian G.,IM2NP | And 10 more authors.
Geochimica et Cosmochimica Acta | Year: 2012

The thermodynamic properties of three aluminous 2:1 clay minerals were acquired at 1.013 bars and at temperatures between 5 and 500. K using various calorimetric methods. Calorimetric measurements were performed on hydrated and dehydrated <2 μm clay fractions of smectite MX-80 (Wyoming), illite IMt-2 (Silver Hill) and beidellite SBId-1 (Black Jack Mine). After purification, the mineralogical analyses gave the following structural formulae: Na 0.409K 0.024Ca 0.009(S i3.738Al 0.262)(Al 1.598Mg 0.214Fe 0.173 3+Fe 0.035 2+)O 10(OH) 2,K 0.762Na 0.044(Si 3.387A l0.613)(A l1.427Mg 0.241Fe 0.292 3+Fe 0.084 2+)O 10(OH) 2 and Ca 0.185K 0.104(Si 3.574Al 0.426)(Al 1.812Mg 0.09Fe 0.112 3+)O 10(OH) 2 for smectite MX-80, illite IMt-2 and beidellite SBId-1, respectively. Heat capacities were measured by low temperature adiabatic calorimetry and differential scanning calorimetry, from 5 to 500. K. Standard enthalpies of formation were obtained from solution-reaction calorimetry at 298.15. K. The standard Gibbs free energies of formation of the clay minerals were also calculated, together with the equilibrium constants at 25. °C, for anhydrous and hydrated minerals. A comparison between these experimental data and estimated values obtained from prediction models available in the literature, enabled the calculation method that appears to be the most relevant to be selected, at least for aluminous 2:1 clay minerals. © 2012 Elsevier Ltd.

Lacruche M.,Ecole Nationale Superieure des Mines de Saint - Etienne CMP | Beringuier-Boher N.,Ecole Nationale Superieure des Mines de Saint - Etienne CMP | Dutertre J.-M.,Ecole Nationale Superieure des Mines de Saint - Etienne CMP | Rigaud J.-B.,Ecole Nationale Superieure des Mines de Saint - Etienne CMP | Kussener E.,IM2NP
Proceedings of the 2016 Design, Automation and Test in Europe Conference and Exhibition, DATE 2016 | Year: 2016

This paper presents a study on the effect of Forward Body Biasing on the laser fault sensitivity of a CMOS 90nm microcontroller. Tests were performed on a register of this target, under several supply voltage and body bias settings, showing significant laser sensitivity variations. Based on these results, a method which aims at decreasing fault repeatability by using variable supply voltage and body bias settings is proposed. Finally, tests are performed on an implementation of this method on a temporally redundant AES and the results are presented. © 2016 EDAA.

Ouelha S.,Signature | Mesquida J.-R.,Signature | Chaillan F.,Signature | Courmontagne Ph.,IM2NP
OCEANS 2013 MTS/IEEE - San Diego: An Ocean in Common | Year: 2013

This paper addresses the feature selection problem encountered in underwater acoustic data mining. Feature selection is a preamble of any data mining algorithm, allowing a priori dimension reduction and better interpretation of data. Here, we propose a new feature selection technique, based on the maximum marginal diversity principle. Our approach is applied on various real dataset, including underwater acoustic data. © 2013 MTS.

Panciera F.,IM2NP
Applied Physics Letters | Year: 2010

We investigated the thermal evolution of end-of-range (EOR) defects in germanium and their impact on junction thermal stability. After solid-phase epitaxial regrowth of a preamorphized germanium layer, EOR defects exhibiting dislocation loop-like contrast behavior are present. These defects disappear during thermal annealing at 400 °C, while boron electrical deactivation occurs. After the whole defect population vanishes, boron reactivation is observed. These results indicate that germanium self-interstitials, released by EOR defects, are the cause of B deactivation. Unlike in Si, the whole deactivation/reactivation cycle in Ge is found to take place while the maximum active B concentration exceeds its solubility limit. © 2010 American Institute of Physics.

Piombini H.,French Atomic Energy Commission | Dieudonne X.,French Atomic Energy Commission | Wood T.,IM2NP | Flory F.,IM2NP
Optical Review | Year: 2013

Sol-gel applications require very thick layers with a good understanding of the interfaces. To address this problem, we have installed at CEA Le Ripault a characterization bench using guided waves with assistance from the IM2NP lab in Marseille. This bench allows us to measure the thickness and the refractive index and determine the extinction coefficient of a thin layer. We can distinguish losses at interfaces from those in the bulk according to the chosen propagation mode. This allows us to know if we can stack elementary layers to make thick layers without incurring problems. © 2013 The Optical Society of Japan.

Berche A.,IM2NP | Benigni P.,IM2NP | Rogez J.,IM2NP | Record M.-C.,IM2NP
Intermetallics | Year: 2014

The La-Mg-Zn phase diagram is experimentally investigated at 595 K, x La > 4% and the corresponding isothermal section is partially determined. This section includes 5 substitutional solid solutions based on the binary compounds (LaMg, LaZn, LaMg3, LaMg10.3 and La 2Zn17) and three ternary phase (La8(Mg,Zn) 92, La3(Mg,Zn)11 and La4.27Mg 2.89Zn30). The enthalpies of mixing in the ternary solid solutions are calculated at 298 K on the basis of tin solution calorimetry experiments. © 2013 Elsevier B.V. All rights reserved.

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