Download or read book Extraction de bore par oxydation du silicium liquide pour applications photovolta ques written by Mathieu Vadon and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'extraction du bore du silicium liquide est une étape d'une chaîne de procédés de purification de silicium de qualité suffisante pour les applications photovoltaïques. Cette thèse étudie en priorité le procédé dit "gaz froid" qui consiste en l'injection d'un mélange de gaz Ar-H2-H2O sur du silicium liquide chauffé électromagnétiquement. Une deuxième méthode similaire ("procédé plasma") où on injecte un plasma thermique issu d'un mélange Ar-H2-O2 a également été étudiée. Un modèle est nécessaire afin d'optimiser le procédé pour économiser de l'énergie.Les trois objectifs du modèle sont la prédiction du flux de silicium issu de la surface (vitesse d'oxydation), du flux de bore issu de la surface (pour avoir la vitesse de purification), et du seuil de passivation. Le seuil de passivation est la limite de concentration d'oxydant au-delà de laquelleil apparait une couche de silice passivante qui empêche la purification. Afin de minimiser la consommation d'énergie en accélérant le procédé, on cherche à injecter une concentration d'oxydant juste en dessous du seuil de passivation.De précédentes études ont montré que le facteur limitant pour les flux de bore et de silicium est le transport d'oxydant dans la phase gaz. Ainsi, nous avons fait un modèle monodimensionnel réactif-diffusif à l'équilibre thermodynamique de la couche limite gazeuse. Selon ce modèle, l'effet de la formation d'aérosols de silice est de diviser par deux le flux d'oxydant vers la surface, ce qui sert aux simulations CFD. Cet effet des aérosols de silice sur les flux d'oxydant peut aussi se retrouver si on enlève l'hypothèse d'équilibre thermodynamique des aérosols de silice avec la phase gaz, ce qui est confirmé par des simulations CFD et des expériences.Pour ce qui concerne l'estimation de la vitesse de purification, les données les plus réalistes concernant l'enthalpie de formation de HBO(g) et le coefficient d'activité du bore dans le silicium liquide ont été sélectionnées. Nous obtenons une bonne prédiction de la vitesse de purification à différentes températures et concentrations d'oxydant, y compris pour le cas plasma que nous avons étudié, en utilisant ces données thermodynamiques et en supposant que les produits de réaction de surface SiO(g) et HBO(g) diffusent de manière similaire. Ces coefficients de transfert identiques pour HBO(g) et SiO(g) peuvent s'expliquer par une précipitation simultanée et commune de HBO(g) et SiO(g), selon des mécanismes de germination et croissance restant à déterminer.Un dispositif expérimental de lévitation électromagnétique de silicium sous un jet oxydant a été monté. La mesure et le contrôle de température d'une bille de silicium ont été mis en oeuvre ce qui permettra la mesure sans contaminations de données thermodynamiques concernant les impuretés .Le seuil de passivation mesuré sur quelques expériences disponibles peut être prédit par notre modèle d'oxydation (associé au facteur deux représentant les aérosols de silice), si on l'associe à un critère proposé dans la littérature, qui couple la fraction du flux d'oxydant arrivant à la surface à une loi d'équilibre entre SiO(g), Si(l) et SiO2(s/l). Nous montrons dans cette thèse que la couche passivante n'est compatible avec des aérosols de silice que si ces aérosols ne sont pas en équilibre avec la phase gaz. La cinétique de formation des aérosols de silice doit donc être étudiée plus en détails.

Download or read book CODATA Key Values for Thermodynamics written by J. D. Cox and published by Chem/Mats-Sci/E. This book was released on 1989 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Thermodynamics of Materials written by C. H. P. Lupis and published by North Holland. This book was released on 1983 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The SGTE Casebook written by K Hack and published by Elsevier. This book was released on 2008-01-25 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Scientific Group Thermodata Europe (SGTE) is a consortium of European and North American research groups developing thermodynamic databases and software to model the thermodynamic properties of metals and other materials. Understanding these properties is critical to improving the processing of metals and their performance in such areas as resistance to high-temperature corrosion.This substantially revised new edition explores both the theoretical background to thermodynamic modelling and its wide range of practical applications. These applications include the analysis of hot salt and other types of high-temperature corrosion, understanding the loss of corrosion resistance in stainless and other types of steel, the processing of steels, as well as the use of thermodynamics to improve the functionality of materials for microelectronics and lighting applications, and in the analysis of nuclear safety issues. New case studies also illustrate applications to kinetically-controlled processes such as the solidification and heat treatment of alloys as well as the production of silicon and titanium oxide pigment.The SGTE casebook is a valuable reference for those manufacturing steels and other materials, those using materials in high-temperature applications such as the power industry and in other areas such as microelectronics and lighting. - This updated and revised edition explores theoretical background to thermodynamic modelling - Practical applications are provided, including types of high-temperature corrosion - Valuable reference for the power and microelectronics industry

Download or read book Flexoelectricity in Liquid Crystals written by Agnes Buka and published by World Scientific. This book was released on 2013 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.

Download or read book ZnO Thin Films written by Paolo Mele and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide (ZnO) is an n-type semiconductor with versatile applications such as optical devices in ultraviolet region, piezoelectric transducers, transparent electrode for solar cells and gas sensors. This book "ZnO Thin Films: Properties, Performance and Applications" gives a deep insight in the intriguing science of zinc oxide thin films. It is devoted to cover the most recent advances and reviews the state of the art of ZnO thin films applications involving energy harvesting, microelectronics, magnetic devices, photocatalysis, photovoltaics, optics, thermoelectricity, piezoelectricity, electrochemistry, temperature sensing. It serves as a fundamental information source on the techniques and methodologies involved in zinc oxide thin films growth, characterization, post-deposition plasma treatments and device processing. This book will be invaluable to the experts to consolidate their knowledge and provide insight and inspiration to beginners wishing to learn about zinc oxide thin films.

Download or read book Thermodynamic Properties of Minerals and Related Substances at 298 15 K and 1 Bar 105 Pascals Pressure and at Higher Temperatures written by Richard A. Robie and published by . This book was released on 1995 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metallic Oxynitride Thin Films by Reactive Sputtering and Related Deposition Methods Processes Properties and Applications written by Filipe Vaz and published by Bentham Science Publishers. This book was released on 2013-06-21 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oxynitride thin film technology is rapidly impacting a broad spectrum of applications, ranging from decorative functions (through optoelectronics) to corrosion resistance. Developing a better understanding of the relationships between deposition processes, structure and composition of the deposited films is critical to the continued evolution of these applications. This e-book provides valuable information about the process modeling, fabrication and characterization of metallic oxynitride-based thin films produced by reactive sputtering and some related deposition processes. Its contents are spread in twelve main and concise chapters through which the book thoroughly reviews the bases of oxynitride thin film technology and deposition processes, sputtering processes and the resulting behaviors of these oxynitride thin films. More importantly, the solutions for the growth of oxynitride technology are given in detail with an emphasis on some particular compounds. This is a valuable resource for academic learners studying materials science and industrial coaters, who are concerned not only about fundamental aspects of oxynitride synthesis, but also by their innate material characteristics.

Download or read book Nonlinear Optical Materials written by Jerome V. Moloney and published by Springer Science & Business Media. This book was released on 1998-08-13 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mathematical methods play a significant role in the rapidly growing field of nonlinear optical materials. This volume discusses a number of successful or promising contributions. The overall theme of this volume is twofold: (1) the challenges faced in computing and optimizing nonlinear optical material properties; and (2) the exploitation of these properties in important areas of application. These include the design of optical amplifiers and lasers, as well as novel optical switches. Research topics in this volume include how to exploit the magnetooptic effect, how to work with the nonlinear optical response of materials, how to predict laser-induced breakdown in efficient optical devices, and how to handle electron cloud distortion in femtosecond processes.

Download or read book Scientific Canadian Mechanics Magazine and Patent Office Record written by Canada. Patent Office and published by . This book was released on 1966-03 with total page 1070 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book American Fertilizers written by Perry Eugene Howard and published by . This book was released on 1932 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this publication is given a brief description of the production of commercial fertilizer. It is believed that this description, which complex technical discussion and statistics are avoided, will be of use to students, as well as farmers and gardeners.

Download or read book Thermodynamic Properties Of Individual Substances written by L. V. Gurvich and published by CRC Press. This book was released on 1990-09-01 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Water Treatment Handbook written by and published by . This book was released on 2007 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt: