Download or read book Contribution l tude des propri t s lectriques et photovolta ques des structures m tal semiconducteur et m tal isolant tunnel semiconducteur written by Hao Nguyen Phu and published by . This book was released on 1984 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'aspect "modélisation" concerne l'effet des résistances parasites sur la performance des cellules photovoltaïques, les réponses spectrales théoriques des photopiles mis tunnel et ainsi que l'élaboration d'un modèle électrique constitué de capacités différentielles sur les mêmes structures. L'aspect "caractérisation" comporte la réalisation d'un ensemble expérimental de mesure de la variation de la longueur de diffusion des porteurs minoritaires dans ITO/P-INP, l'étude de la modification des hauteurs de barrière au/oxyde/N-INP, et l'application des techniques de "caractérisation assistée par calculateur" pour déterminer les paramètres physiques à partir de courbes expérimentales

Download or read book Contribution l tude des structures MIS M tal Isolant Semi conducteur written by Alain Bégon (auteur d'une thèse de physique).) and published by . This book was released on 1976 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'EFFET TUNNEL A TRAVERS LA COUCHE ISOLANTE JOUE UN ROLE IMPORTANT DANS LE COMPORTEMENT, MAIS CELUI-CI DEPEND BIEN SUR AUSSI DU SEMICONDUCTEUR. EXAMEN DES PHENOMENES AVEC LE SILICIUM ET LE GERMANIUM EN ENVISAGEANT 2 DOPAGES TRES DIFFERENTS. ON FAIT UNE PREMIERE ETUDE EN CONTINU AFIN DE DEDUIRE, DES CARACTERISTIQUES I-V, LES MODES DE CONDUCTION QUI INTERVIENNENT. LE PARAMETRE PHYSIQUE ESSENTIEL SERA LA TEMPERATURE. ENSUITE ON ETUDIE LE COMPORTEMENT DE CES STRUCTURES EN REGIME HARMONIQUE CE QUI NOUS PERMETTRA D'OBTENIR DES INFORMATIONS SUR LES INTERFACES: ON UTILISE POUR CELA LA VARIATION DE LA CONDUCTANCE DIFFERENTIELLE ET DE LA CAPACITE DYNAMIQUE.

Download or read book REALISATION DE STRUCTURES METAL ISOLANT SEMI CONDUCTEUR ETUDE PAR SPECTROSCOPIES ELECTRONIQUES ET CARACTERISATIONS ELECTRIQUES written by Sandrine Merle and published by . This book was released on 1999 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: LES PERFORMANCES DES STRUCTURES METAL/ISOLANT/SEMI-CONDUCTEUR SONT CONDITIONNEES PAR LA QUALITE DE L'ISOLANT ET PAR LA MAITRISE DES PROPRIETES PHYSICO-CHIMIQUES DES INTERFACES ISOLANT/SEMI-CONDUCTEUR ET METAL/ISOLANT. LA PREMIERE PARTIE DE CE MEMOIRE EST DONC CONSACREE A L'ETUDE DES PROPRIETES DE DIFFERENTES COUCHES D'ALUMINE REALISEES SUR SUBSTRATS DE SILICIUM PAR PULVERISATION CATHODIQUE OU PAR EVAPORATION SOUS ULTRA-VIDE EN FONCTION DE DIVERS PARAMETRES EXPERIMENTAUX TELS QUE LA VITESSE D'EVAPORATION ET L'EPAISSEUR DES COUCHES DIELECTRIQUES. LA QUALITE DE CES COUCHES A ETE CONTROLEE PAR SPECTROSCOPIE DES ELECTRONS AUGER (A.E.S.), PAR SPECTROSCOPIE DES PHOTOELECTRONS SOUS EXCITATION X (X.P.S.) ET PAR CARACTERISATION ELECTRIQUE C(V). NOUS AVONS CONSTATE QU'UN CHAUFFAGE DU SUBSTRAT DURANT LE DEPOT D'ALUMINE ET DES VITESSES D'EVAPORATION TROP IMPORTANTES SEMBLENT ETRE NEFASTES A LA QUALITE DES COMPOSANTS. LA DETERMINATION DES PROPRIETES DE SURFACE DES COUCHES ISOLANTES A ETE OBTENUE PAR X.P.S. CETTE DERNIERE ETUDE EST TRES IMPORTANTE CAR LES CHANGEMENTS DE STOECHIOMETRIE, D'ORDRE ET DE STRUCTURE ELECTRONIQUE DE LA SURFACE DE L'ALUMINE VONT JOUER UN ROLE SUR LA CROISSANCE, LA MORPHOLOGIE ET LA STABILITE DU METAL DEPOSE. APRES AVOIR OPTIMISE LA QUALITE DES COUCHES DIELECTRIQUES, NOUS AVONS REALISE DES STRUCTURES M.I.S. A BASE D'INP (100). LA COMBINAISON DE L'A.E.S. ET DE MESURES ELECTRIQUES MONTRE QUE LA STABILITE DE L'INP (100), NETTOYE IONIQUEMENT, EST AMELIOREE LORSQUE LE SEMI-CONDUCTEUR EST RESTRUCTURE PAR EVAPORATION D'ATOMES D'ANTIMOINE. EN EFFET, UNE COUCHE TAMPON D'INSB EST CREEE EMPECHANT LA MIGRATION DES ATOMES DE PHOSPHORE ET D'INDIUM AU TRAVERS DE LA COUCHE D'ALUMINE. DE PLUS, LORS DE LA METALLISATION DE CES STRUCTURES, PAR EVAPORATION D'ATOMES D'OR, NOUS AVONS CONSTATE UNE AMELIORATION DES RESULTATS ELECTRIQUES LORSQUE LE DEPOT EST EFFECTUE SUR ALUMINE ENRICHIE EN ALUMINIUM.

Download or read book Contribution l tude des propri t s lectroniques des structures M I S sur InP Au BN InP written by Mohammed Barrada and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le travail présenté dans ce mémoire concerne la mise en œuvre de méthodes de caractérisations électriques permettant d'évaluer la qualité des structures métal/isolant/semiconducteur (MIS: Au/BN/InP) et de mieux comprendre certains problèmes rencontrés. Les structures étudiées ont été élaborées par dépôt chimique en phase vapeur assisté par plasma R.F. (PECVD), les substrats d'InP étant places soit dans le plasma (structures DP) soit hors de la zone plasma (structures HP). Une étude qualitative des instabilités électriques a été réalisée sous deux aspects. Le premier aspect est relatif au phénomène d'hystérésis des courbes C(V) à 1 MHz et sa variation avec l'amplitude de l'excursion en tension et la vitesse de balayage. Le deuxième aspect concerne les phénomènes de dérive en fonction du temps à diverses températures (77, 300 et 400 K). Cette étude a mis en évidence à 300 K la prépondérance du mécanisme de piégeage des porteurs par des états lents par rapport à la migration des ions mobiles. A 400 k, les effets sont inversés, les ions mobiles ayant un effet dominant. En se basant sur ces observations, nous avons pu faire une étude quantitative concernant les charges fixes et les ions mobiles dans l'isolant à 400 k (signes, densités et positions à l'équilibre). Les phénomènes de dispersion fréquentielle ont été ensuite étudiés. Afin de comprendre ce comportement dans nos structures, plusieurs modèles ont été examinés. En accumulation, la présence des courants de fuite dans l'isolant semble être à l' origine de la dispersion fréquentielle dans les structures DP. Pour les structures HP, ce phénomène est attribué à la présence de pièges dans le BN dont la charge varie par effet tunnel direct avec la bande de conduction du semiconducteur (Mui et Al). En régime de déplétion, la dispersion fréquentielle est attribuée à la présence de pièges dans l'isolant qui échangent des électrons avec la bande de conduction du semiconducteur par effet tunnel indirect (modèle de Preier). Enfin, une étude de la densité d'états d'interface Nss, par les méthodes de DLTS et Terman a été faite. Pour les structures HP, la méthode de Terman a conduit à un minimum de Nss d'environ 2x10(11) cm(-2) eV(-1). Nos résultats mettent en évidence, la meilleure qualité des structures HP.

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 Organic Solid State Lasers written by Sébastien Forget and published by Springer. This book was released on 2013-07-03 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic lasers are broadly tunable coherent sources, potentially compact, convenient and manufactured at low-costs. Appeared in the mid 60’s as solid-state alternatives for liquid dye lasers, they recently gained a new dimension after the demonstration of organic semiconductor lasers in the 90's. More recently, new perspectives appeared at the nanoscale, with organic polariton and surface plasmon lasers. After a brief reminder to laser physics, a first chapter exposes what makes organic solid-state organic lasers specific. The laser architectures used in organic lasers are then reviewed, with a state-of-the-art review of the performances of devices with regard to output power, threshold, lifetime, beam quality etc. A survey of the recent trends in the field is given, highlighting the latest developments with a special focus on the challenges remaining for achieving direct electrical pumping of organic semiconductor lasers. A last chapter covers the applications of organic solid-state lasers.

Download or read book X Ray and Neutron Reflectivity Principles and Applications written by Jean Daillant and published by Springer Science & Business Media. This book was released on 2003-07-01 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reflection of and neutrons from surfaces has existed as an x-rays exp- imental for almost it is in the last technique fifty Nevertheless, only years. decade that these methods have become as of enormously popular probes This the surfaces and interfaces. to be due to of several appears convergence of intense different circumstances. These include the more n- availability be measured orders tron and sources that can over (so reflectivity x-ray many of and the much weaker surface diffuse can now also be magnitude scattering of thin films and studied in some the detail); growing importance multil- basic the realization of the ers in both and technology research; important which in the of surfaces and and role roughness plays properties interfaces; the of statistical models to characterize the of finally development topology its and its characterization from on roughness, dependence growth processes The of and to surface scattering experiments. ability x-rays neutro4s study four five orders of in scale of surfaces over to magnitude length regardless their and also their to ability probe environment, temperature, pressure, etc. , makes these the choice for buried interfaces often probes preferred obtaining information about the microstructure of often in statistical a global surfaces, the local This is manner to complementary imaging microscopy techniques, of such studies in the literature witnessed the veritable by explosion published the last few Thus these lectures will useful for over a resource years.

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 Trichier written by Alessandra Ceretto and published by Lulu.com. This book was released on with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Laser 50 Years Of Discoveries written by Fabien Bretenaker and published by World Scientific. This book was released on 2014-10-27 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique book provides an overview of the principle and applications of lasers enriched with numerous illustrations.Being over fifty years old, lasers continue to amaze us. Their performance characteristics are constantly reaching new limits, and the scope of their applications continues to expand. Yet, it took years of effort by teams of physicists to transform the fundamental notions of Einstein into the first experimental beam of laser light. And history is still going on as fundamental research is now triggered by its remarkable properties.This book addresses every aspects of laser light, from its fundamental principles to its industrial applications, at a level particularly suited for high school teachers, students, and anybody curious about science and technology.

Download or read book Physical Properties of Amorphous Materials written by David Adler and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Institute for Amorphous Studies was founded in 1982 as the international center for the investigation of amorphous mate rials. It has since played an important role in promoting the und er standing of disordered matter in general. An Institute lecture series on "Fundamentals of Amorphous Materials and Devices" was held during 1982-83 with distinguished speakers from universities and industry. These events were free and open to the public ,and were attended by many representatives of the scientific community. The lectures themselves were highly successful inasmuch as they provided not only formal instruction but also an opportunity for vigorous and stimulating debate. That last element could not be captured within the pages of a book I but the lectures concentrated on the latest advances in the field I which is why their essential contents are he re reproduced in collective form. Together they constitute an interdisciplinary status report of the field. The speakers brought many different viewpoints and a variety of back ground experiences io bear on the problems involved I but though language and conventions vary I the essential unity of the concerns is very clear I as indeed are the ultimate benefits of the many-sided approach.