Download or read book PROPRIETES STRUCTURALES ET ELECTRONIQUES A L INTERFACE SILICIUM SILICE written by ANTONIO.. CORREIA and published by . This book was released on 1993 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'OXYDATION THERMIQUE D'UNE SURFACE DE SILICIUM POLIE MECANIQUEMENT PRODUIT DES FAUTES D'EMPILEMENT A L'INTERFACE DONT LES DISLOCATIONS PARTIELLES SONT DECOREES PAR DU SILICIURE DE CUIVRE DANS UN SILICIUM FUSION DE ZONE ET PAR DE L'OXYGENE DANS UN SILICIUM CZOCHRALSKI. L'OXYDATION D'UNE SURFACE POLIE MECANOCHIMIQUEMENT (SUPPRESSION DE LA ZONE ECROUIE) GENERE DES RESEAUX DE DISLOCATIONS QUI PEUVENT SERVIR DE SITES DE NUCLEATION A DES COLONIES DE CUIVRE. ON N'OBSERVE JAMAIS DE CO-PRECIPITATION D'OXYGENE ET DE METAUX. LA MICROSTRUCTURE DE CES DEFAUTS DETERMINE LES PROPRIETES ELECTRONIQUES DE L'INTERFACE SILICIUM-SILICE. A PARTIR DES RESULTATS DE CARACTERISATION STRUCTURALE ET PHYSICO-CHIMIQUE DE L'INTERACTION DEFAUT-IMPURETE D'UNE PART, ET DES RESULTATS ELECTRIQUES (LONGUEUR DE DIFFUSION ET VITESSE DE RECOMBINAISON SUPERFICIELLE DES PORTEURS DE CHARGE MINORITAIRES) D'AUTRE PART, ON ANALYSE LE ROLE DES FAUTES D'EMPILEMENT, DES DISLOCATIONS, DE LA SEGREGATION D'OXYGENE OU DE SILICIURE DE CUIVRE SUR LES PROPRIETES ELECTRONIQUES DE L'INTERFACE SILICIUM/SILICE. ON EVALUE AINSI L'EFFICACITE DE L'OXYDATION THERMIQUE EN TANT QUE PROCEDE D'AMELIORATION DES PROPRIETES ELECTRONIQUES DES COUCHES SUPERFICIELLES DU SILICIUM

Download or read book Development characterization and modeling of interfaces for high efficiency silicon heterojunction solar cells written by Renaud Varache and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'interface entre le silicium amorphe (a-Si:H) et le silicium cristallin (c-Si) est un constituent clés de cellules solaires à haut rendement reposant sur des procédés à basse température. Trois propriétés de l'interface déterminent le rendement des cellules solaires à hétérojonction de silicium: les décalages de bandes entre a-Si:H et c-Si, les défauts d'interface et la courbure de bande dans c-Si. Ces trois aspects sont traités dans ces travaux de thèse.Dans un premier un temps, un calcul analytique de la courbure de bande dans c-Si est développé. Il repose sur l'approximation d'une densité d'état (DE) constante dans la bande interdite de a-Si:H. L'influence des principaux paramètres de la structure sur la courbure de bande est étudiée : décalage de bande, densité d'état dans a-Si:H, défaut d'interface, etc. La présence d'un effet de confinement quantique est discutée. Grâce à une comparaison entre ces calculs et des mesures de conductance planaire en fonction de la température sur des structures (p)a-Si:H/(n)c-Si et (n)a-Si:H/(p)c-Si, les décalages de bande de valence et de conduction ont pu être estimés à 0.36 eV et 0.15 eV respectivement. En outre, il est montré que le décalage de la bande de valence est indépendant de la température, alors que le décalage de la bande de conduction suit les évolutions des bandes interdites de c-Si et a-Si:H. Ces mesures tendent à prouver que le 'branch point' dans a-Si:H est indépendant du dopage.Ensuite, les calculs analytiques sont approfondis pour prendre en compte différents aspects de la structure complète incorporée dans les cellules : contact avec un oxyde transparent conducteur, présence d'une couche de a-Si:H non-dopée à l'interface. A l'aide de simulations numériques et à la lumière de mesures de conductance planaire conjuguées à des mesures de la qualité de passivation de l'interface, des pistes pour optimiser les cellules à hétérojonction sont commentées. En particulier, il est montré qu'un optimum doit être trouvé entre une bonne passivation et une courbure de bande suffisante. Ceci peut être accompli par un réglage fin des propriétés de la couche tampon (épaisseur, dopage), du contact (travail de sortie élevé) et de l'émetteur (p)a-Si:H (densité de défauts et épaisseur). En particulier, un émetteur avec une DE importante conduit paradoxalement à de meilleures performances.Enfin, un nouveau type d'interface a été développé. La surface de c-Si a été oxydée volontairement dans de l'eau pure dé-ionisée à 80 °C avant le dépôt de (p)a-Si:H afin d'obtenir une structure (p)a-Si:H/SiO2/(n)c-Si. A l'aide d'un modèle de courant par effet tunnel implémenté dans le logiciel de simulation numérique AFORS-HET, l'effet d'une couche à grande bande interdite (comme c'est le cas pour SiO2) sur les performances de cellules est étudié : le facteur de forme et le courant de court-circuit sont extrêmement réduits. En revanche, une couche de SiO2 n'a que peu d'impact sur les propriétés optiques de la structure. Expérimentalement, les échantillons réalisés montrent une qualité de passivation à mi-chemin entre le cas sans couche tampon et le cas avec (i)a-Si:H : ceci est expliqué par la présence d'une charge fixe négative dans l'oxyde. La courbure de bande dans c-Si est moins affectée par la présence d'une couche d'oxyde que d'une couche de (i)a-Si:H. Les cellules solaires réalisées démontrent que le concept a le potentiel d'aboutir à de hauts rendements : sur des structures non-optimisées, une tension de court-circuit supérieure à 650 mV a été démontrée, alors que l'oxyde ne semble pas limiter le transport de charge.

Download or read book Colloidal Silica written by Horacio E. Bergna and published by CRC Press. This book was released on 2005-12-19 with total page 926 pages. Available in PDF, EPUB and Kindle. Book excerpt: In spite of the apparent simplicity of silica's composition and structure, scientists are still investigating fundamental questions regarding the formation, constitution, and behavior of colloidal silica systems. Colloidal Silica: Fundamentals and Applications introduces new information on colloid science related to silica chemistry as well

Download or read book Pandex Current Index to Scientific and Technical Literature written by and published by . This book was released on 1970 with total page 1370 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Semiconductor Physics Quantum Electronics and Optoelectronics written by and published by . This book was released on 2000 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1990 with total page 1608 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physical Chemistry of Magmas written by Leonid L. Perchuk and published by Springer Science & Business Media. This book was released on 2013-04-09 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physical Chemistry of Magmas investigates the properties, structure, and phase relationships of silicate melts with invited contributions from an international team of experts. Data and some rules for estimating the properties and structures of melts, as well as the implications of the physical chemistry of silicate liquids to igneous petrology are presented. The second section then focuses on phase relationships, with particular attention on the application of experimental and theoretical petrology to modeling the origin of certain magmas.

Download or read book Atomistic Simulation of Anistropic Crystal Structures at Nanoscale written by Jia Fu and published by BoD – Books on Demand. This book was released on 2019-05-10 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiscale simulations of atomistic/continuum coupling in computational materials science, where the scale expands from macro-/micro- to nanoscale, has become a hot research topic. These small units, usually nanostructures, are commonly anisotropic. The development of molecular modeling tools to describe and predict the mechanical properties of structures reveals an undeniable practical importance. Typical anisotropic structures (e.g. cubic, hexagonal, monoclinic) using DFT, MD, and atomic finite element methods are especially interesting, according to the modeling requirement of upscaling structures. It therefore connects nanoscale modeling and continuous patterns of deformation behavior by identifying relevant parameters from smaller to larger scales. These methodologies have the prospect of significant applications. I would like to recommend this book to both beginners and experienced researchers.

Download or read book The Perfect Slime written by Hans-Curt Flemming and published by IWA Publishing. This book was released on 2016-09-15 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Perfect Slime presents the latest state of knowledge and all aspects of the Extracellular Polymeric Substances, (EPS) matrix – from the ecological and health to the antifouling perspectives. The book brings together all the current material in order to expand our understanding of the functions, properties and characteristics of the matrix as well as the possibilities to strengthen or weaken it. The EPS matrix represents the immediate environment in which biofilm organisms live. From their point of view, this matrix has paramount advantages. It allows them to stay together for extended periods and form synergistic microconsortia, it retains extracellular enzymes and turns the matrix into an external digestion system and it is a universal recycling yard, it protects them against desiccation, it allows for intense communication and represents a huge genetic archive. They can remodel their matrix, break free and eventually, they can use it as a nutrient source. The EPS matrix can be considered as one of the emergent properties of biofilms and are a major reason for the success of this form of life. Nevertheless, they have been termed the “black matter of biofilms” for good reasons. First of all: the isolation methods define the results. In most cases, only water soluble EPS components are investigated; insoluble ones such as cellulose or amyloids are much less included. In particular in environmental biofilms with many species, it is difficult to impossible isolate, separate the various EPS molecules they are encased in and to define which species produced which EPS. The regulation and the factors which trigger or inhibit EPS production are still very poorly understood. Furthermore: bacteria are not the only microorganisms to produce EPS. Archaea, Fungi and algae can also form EPS. This book investigates the questions, What is their composition, function, dynamics and regulation? What do they all have in common?

Download or read book Zinc Oxide written by Hadis Morkoç and published by John Wiley & Sons. This book was released on 2008-12-03 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first systematic, authoritative and thorough treatment in one comprehensive volume presents the fundamentals and technologies of the topic, elucidating all aspects of ZnO materials and devices. Following an introduction, the authors look at the general properties of ZnO, as well as its growth, optical processes, doping and ZnO-based dilute magnetic semiconductors. Concluding sections treat bandgap engineering, processing and ZnO nanostructures and nanodevices. Of interest to device engineers, physicists, and semiconductor and solid state scientists in general.

Download or read book Evolution of Thin Film Morphology written by Matthew Pelliccione and published by Springer Science & Business Media. This book was released on 2008-01-29 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this book is on modeling and simulations used in research on the morphological evolution during film growth. The authors emphasize the detailed mathematical formulation of the problem. The book will enable readers themselves to set up a computational program to investigate specific topics of interest in thin film deposition. It will benefit those working in any discipline that requires an understanding of thin film growth processes.

Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.

Download or read book The Physics of Non crystalline Solids written by L. David Pye and published by Taylor & Francis Group. This book was released on 1992 with total page 788 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text encapsulates the papers presented in 1991 at a conference organized by the Society of Glass Technology (held every six years). The complex physics and interdisciplinary nature of glass technology is emphasized. It includes information on resonance phenomena and ionic transport.

Download or read book Dielectric Phenomena in Solids written by Kwan Chi Kao and published by Elsevier. This book was released on 2004-05-11 with total page 601 pages. Available in PDF, EPUB and Kindle. Book excerpt: In general, a dielectric is considered as a non-conducting or insulating material (such as a ceramic or polymer used to manufacture a microelectronic device). This book describes the laws governing all dielectric phenomena.·A unified approach is used in describing each of the dielectric phenomena, with the aim of answering "what?", "how?" and "why" for the occurrence of each phenomenon;·Coverage unavailable in other books on ferroelectrics, piezoelectrics, pyroelectrics, electro-optic processes, and electrets;·Theoretical analyses are general and broadly applicable;·Mathematics is simplified and emphasis is placed on the physical insight of the mechanisms responsible for the phenomena;·Truly comprehensive coverage not available in the current literature.

Download or read book Fast Ion Transport in Solids written by B. Scrosati and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main motivation for the organization of the Advanced Research Workshop in Belgirate was the promotion of discussions on the most recent issues and the future perspectives in the field of Solid State lonics. The location was chosen on purpose since Belgirate was the place were twenty years ago, also then under the sponsorship of NATO, the very first international meeting on this important and interdisciplinary field took place. That meeting was named "Fast Ion Transport in Solids" and gathered virtually everybody at that time having been active in any aspect of motion of ions in solids. The original Belgirate Meeting made for the first time visible the technological potential related to the phenomenon of the fast ionic transport in solids and, accordingly, the field was given the name "Solid State lonics". This field is now expanded to cover a wide range of technologies which includes chemical sensors for environmental and process control, electrochromic windows, mirrors and displays, fuel cells, high performance rechargeable batteries for stationary applications and electrotraction, chemotronics, semiconductor ionics, water electrolysis cells for hydrogen economy and other applications. The main idea for holding an anniversary meeting was that of discussing the most recent issues and the future perspectives of Solid State lonics just twenty years after it has started at the same location on the lake Maggiore in North Italy.

Download or read book Spectroscopic Methods in Mineralogy and Geology written by Frank C. Hawthorne and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 18 of Reviews in Mineralogy provides a general introduction to the use of spectroscopic techniques in Earth Sciences. It gives an Introduction To Spectroscopic Methods and covers Symmetry, Group Theory And Quantum Mechanics; Spectrum-Fitting Methods; Infrared And Raman Spectroscopy; Inelastic Neutron Scattering; Vibrational Spectroscopy Of Hydrous Components; Optical Spectroscopy; Mossbauer Spectroscopy; MAS NMR Spectroscopy Of Minerals And Glasses; NMR Spectroscopy And Dynamic Processes In Mineralogy And Geochemistry; X-Ray Absorption Spectroscopy: Applications In Mineralogy ind Geochemistry; Electron Paramagnetic Resonance; Auger Electron And X-Ray Photelectron Spectroscopies and Luminescence, X-Ray Emission and New Spectroscopies. The authors of this volume presented a short course, entitled "Spectroscopic Methods in Mineralogy and Geology", May 13-15, 1988, in Hunt Valley, Maryland.