Surface Photovoltage Analysis of Photoactive Materials


Book Description

Symbols and abbreviations -- Light-induced charge separation and surface - photoactive -- Measurement techniques of surface photovoltage signals -- practical aspects of surface photovoltage measurements -- Random walk simulation of surface photovoltage signals in small systems -- Selected applications of surface photovoltage techniques.




Surface Photovoltage Analysis Of Photoactive Materials


Book Description

Surface photovoltage (SPV) techniques provide information about photoactive materials with respect to charge separation in space. This book aims to share experience in measuring and analyzing SPV signals and addresses researchers and developers interested in learning more about and in applying SPV methods. For this purpose, basics about processes in photoactive materials and principles of SPV measurements are combined with examples from research and development over the last two decades.SPV measurements with Kelvin probes, fixed capacitors, electron beams and photoelectrons are explained. Details are given for continuous, modulated and transient SPV spectroscopy. Simulation principles of SPV signals by random walks are introduced and applied for small systems. Application examples are selected for the characterization of silicon surfaces, gallium arsenide layers, electronic states in colloidal quantum dots, transport phenomena in metal oxides and local charge separation across photocatalytic active crystallites.




Photovoltaic and Photoactive Materials


Book Description

The primary objective of this NATO Advanced Study Institute (ASI) was to present an up-to-date overview of various current areas of interest in the field of photovoltaic and related photoactive materials. This is a wide-ranging subject area, of significant commercial and environmental interest, and involves major contributions from the disciplines of physics, chemistry, materials, electrical and instrumentation engineering, commercial realisation etc. Therefore, we sought to adopt an inter disciplinary approach, bringing together recognised experts in the various fields while retaining a level of treatment accessible to those active in specific individual areas of research and development. The lecture programme commenced with overviews of the present relevance and historical development of the subject area, plus an introduction to various underlying physical principles of importance to the materials and devices to be addressed in later lectures. Building upon this, the ASI then progressed to more detailed aspects of the subject area. We were also fortunately able to obtain a contribution from Thierry Langlois d'Estaintot of the European Commission Directorate, describing present and future EC support for activities in this field. In addition, poster sessions were held throughout the meeting, to allow participants to present and discuss their current activities. These were supported by what proved to be very effective feedback sessions (special thanks to Martin Stutzmann), prior to which groups of participants enthusiastically met (often in the bar) to identify and agree topics of common interest.




Conductive Polymers II


Book Description

This report explains the theory of polymer conductivity, and discusses developments in the synthesis of the major polymers. A detailed section on practical applications follows a discussion of the improved electrical and mechanical properties and environmental stability which make such applications possible. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database provides useful references for further reading.




Green Chemistry


Book Description

To an increasing extent, "green chemistry" is a new chemical and engineering approach of chemistry and engineering, dedicated to make manufacturing processes and our world as a whole more sustainable world with a growing tendency. "Green chemistry" approaches are based on ecofriendly technologies, aiming to reduce or eliminate the use of solvents, or render them efficient and safer. Moreover, this scientific field is devoted to reduction or elimination of prevailing environmental and health threats, which typically accompany chemical products and traditional processes. The present book "Green Chemistry" contains 9 selected chapters, starting with a general introductory chapter on "green chemistry," and covers many recent applications and developments based on the principles of "green chemistry." This book is considered the appropriate way to communicate the advances in green materials and their applications to the scientific community. Chemists, scientists and researchers from related areas, and undergraduates involved in environmental issues and interested in approaches to improve the quality of life could find an inspiring and effective guide by reading this book.




Modern Techniques of Spectroscopy


Book Description

The book highlights recent developments in the field of spectroscopy by providing the readers with an updated and high-level of overview. The focus of this book is on the introduction to concepts of modern spectroscopic techniques, recent technological innovations in this field, and current examples of applications to molecules and materials relevant for academia and industry. The book will be beneficial to researchers from various branches of science and technology, and is intended to point them to modern techniques, which might be useful for their specific problems. Spectroscopic techniques, that are discussed include, UV-Visible absorption spectroscopy, XPS, Raman spectroscopy, SERS, TERS, CARS, IR absorption spectroscopy, SFG, LIBS, Quantum cascade laser (QCL) spectroscopy, fluorescence spectroscopy, ellipsometry, cavity-enhanced absorption spectroscopy, such as cavity ring-down spectroscopy (CRDS) and evanescent wave-CRDS both in gas and condensed phases, time-resolved spectroscopy etc. Applications introduced in the different chapters demonstrates the usefulness of the spectroscopic techniques for the characterization of fundamental properties of molecules, e.g. in connection with environmental impact, bio-activity, or usefulness for pharmaceutical drugs, and materials important e.g. for nano-science, nuclear chemistry, or bio-applications. The book presents how spectroscopic techniques can help to better understand substances, which have also great impact on questions of social and economic relevance (environment, alternative energy, etc.).







Photoelectrochemistry and Photovoltaics of Layered Semiconductors


Book Description

This volume aims at bringing together the results of extensive research done during the last fifteen years on the interfacial photoelectronic properties of the inorganic layered semiconducting materials, mainly in relation to solar energy conversion. Significant contributions have been made both on the fundamental aspects of interface characteristics and on the suitability of the layered materials in photoelectrochemical (semiconductor/electrolyte junctions) and in solid state photovoltaic(Schottky and p-n junctions) cells. New insights into the physical and chemical characteristics of the contact surfaces have been gained and many new applications of these materials have been revealed. In particular, the basal plane surface of the layered materials shows low chemical reactivity and specific electronic behaviour with respect to isotropic solids. In electrochemical systems, the inert nature of these surfaces characterized by saturated chemical bonds has been recognized from studies on charge transfer reactions and catalysis. In addition, studies on the role of the d-band electronic transitions and the dynamics of the photogene rated charge carriers in the relative stability of the photoelectrodes of the transition metal dichalcogenides have deepened the understanding of the interfacial photoreactions. Transition metal layered compounds are also recognized as ideal model compounds for the studies Involving surfaces: photoreactions, adsorption phenomena and catalysis, scanning tunneling microscopy and spectroscopy and epitaxial growth of thin films. Recently, quantum size effects have been investigated in layered semiconductor colloids.







Elementary Processes in Organic Photovoltaics


Book Description

This volume presents the results of a multi-year research programme funded by the Deutsche Forschungsgemeinschaft (German Research Council), which explains how organic solar cells work. In this new promising photovoltaic technology, carbon-based materials are deposited by low-cost methods onto flexible substrates, thus allowing devices which open completely new applications like transparent coatings for building, solar cells integrated into clothing or packages, and many more. The investigation of organic solar cells is an interdisciplinary topic, covering physics, chemistry and engineering. The different chapters address topics ranging from the synthesis of new organic materials, to the characterization of the elementary processes such as exciton transport and separation, and the principles of highly efficient device design. /div