Karl W. Böer – författare

Advances in Solar Energy, now in its fifth year, is continuing with topics of the main field of solar energy conversion. However, because of the increasing interest in a solar systems approach, we have decided to include the article of Bockris et al., on Hydrogen Technology, which offers interesting aspects of transport and storage of solar energy, as well as the potential for a versatile fuel. The other articles cover the field of photovoltaics, solar energy-related mate­ rials, wind conversion, solar retrofitting of existing buildings, and new architectural designs in harmony with climate and the comfort of all occupants. These articles give a critical assessment of the present state of the art, and provide a long list of literature for further in-depth studies. I greatly appreciate the assistance of the Editors and referees of the articles for their many constructive suggestions. My special thanks go to Ms. Martha Hobbs for her dedicated work in typesetting the manuscript in the University of Delaware's Publication Office, and to the University of Delaware for their continued support. The accommodating help from Plenum Press and its production staff deserves our grateful acknowledgement.

In Volume 6 of the Advances in Solar Energy we have specifically targeted for a review the rich experience of the Power Utilities. Their hands-on experience in a large variety of means to employ solar energy conversion and to evaluate the technical and economical feasibilities is of great importance to their future use. In designing the lay-out for this volume, we wanted to collect all relevant information, including success and failures and wanted to emphasize the lessons learned from each type of experiment. The publication of such a review now has the advantage of a settled experience in the first phase of solar involvement of the utility industry with a large amount of data analyzed. We are confident that this information will be of great value to direct the future development of the solar energy mix within this industry. We have added to this set of reviews three articles which deal with the most promising high-technology part of solar energy conversion using exclusively solid state devices: solar cells. The development over the last two decades from barely 10% to now in excess of 30% conversion efficiency is breathtaking. In addition, the feasibility of economic midrange efficient thin-film technology holds the promise of opening large sc ale markets in the near future. This field will enter head-on competition for large power generation with more conventional technology.

This handbook gives a complete and detailed survey of the field of semiconductor physics. It addresses every fundamental principle, the most important research topics and results, as well as conventional and emerging new areas of application. Additionally it provides all essential reference material on crystalline bulk, low-dimensional, and amorphous semiconductors, including valuable data on their optical, transport, and dynamic properties.This updated and extended second edition includes essential coverage of rapidly advancing areas in semiconductor physics, such as topological insulators, quantum optics, magnetic nanostructures and spintronic systems. Richly illustrated and authored by a duo of internationally acclaimed experts in solar energy and semiconductor physics, this handbook delivers in-depth treatment of the field, reflecting a combined experience spanning several decades as both researchers and educators. Offering a unique perspective on many issues, SemiconductorPhysics is an invaluable reference for physicists, materials scientists and engineers throughout academia and industry.

This short Introduction into Space Charge E?ects in Semiconductors is designed for teaching the basics to undergraduates and show how space charges are created in semiconductors and what e?ect they have on the el- tric?eldandthe energybanddistributioninsuchmaterials,andconsequently on the current-voltage characteristics in semiconducting devices. Such space charge e?ects were described previously in numerous books, fromtheclassicsofSpenkeandShockleytothemorerecentonesofSeegerand others.Butmanymoredetailedinformationwereonlyavailableintheoriginal literatureandsomeofthemnotatall.Itseemstobeimportanttocollectallin a comprehensive Text that can be presented to students in Physics, Electrical Engineering, and Material Science to create the fundamental knowledge that is now essential for further development of more sophisticated semiconductor devices and solar cells. This book will go through every aspect of space charge e?ects and - scribe them from simple elementaries to the basics of semiconductor devices, systematically and in progressing detail.For simplicity we have chosen this description for a one-dimensional se- conductorthatpermitsasimpledemonstrationoftheresultsgraphicallywi- out requiring sometimes confusing perspective rendering. In order to clarify the principles involved, the book starts with a hy- thetical model, by assuming simple space charge distributions and deriving their e?ects on ?eld and potential distributions, using the Poisson equation. Itemphasizestheimportantsignrelationsoftheinterreactingvariables,space charge, ?eld, and potential (band edges). It then expands into simple semiconductor models that contain an abrupt nn-junction and gives an example of important space chargelimited currents, + as observed in nn -junctions.

This monograph of Electro-Optical E?ects to Visualize Field- and Current- Distributions in Semiconductors consists of ?ve parts, four of which are based ontheresearchofcadmiumsul?de,wherealargenumberofcontributionswere made between 1958 and the late 1960s to directly observe ?eld and current distributionsandinterprettheirresults.Thevisualizationof?elddistributions was accomplished by using the Franz Keldysh e?ect, and the visualization of currentinhomogeneitiesusestheshiftoftheopticalabsorptionedgebyJoule's heating. The ?fth part deals with a review of the explosively developing ?eld of N- and S-shaped current voltage characteristics causing inhomogeneities and instabilities in ?eld and current distributions. This part of the book was composed by Eckehard Sch. oll of the Technical University in Berlin. A major emphasis is given to the ?rst part of the book in which s- tionary high-?eld domains are described. These domains can be used as an essential tool to determine unambiguously certain semiconductor properties, such as the electron density and its mobility as the function of the actual electric ?eld. It is also helpful to determine changes of the work function and electron a?nities between di?erent materials, such as for electrodes and h- erojunctions. Finally, it gives direct information about certain doping and their spacial pro?le.

This short Introduction into Space Charge E?ects in Semiconductors is designed for teaching the basics to undergraduates and show how space charges are created in semiconductors and what e?ect they have on the el- tric?eldandthe energybanddistributioninsuchmaterials,andconsequently on the current-voltage characteristics in semiconducting devices. Such space charge e?ects were described previously in numerous books, fromtheclassicsofSpenkeandShockleytothemorerecentonesofSeegerand others.Butmanymoredetailedinformationwereonlyavailableintheoriginal literatureandsomeofthemnotatall.Itseemstobeimportanttocollectallin a comprehensive Text that can be presented to students in Physics, Electrical Engineering, and Material Science to create the fundamental knowledge that is now essential for further development of more sophisticated semiconductor devices and solar cells. This book will go through every aspect of space charge e?ects and - scribe them from simple elementaries to the basics of semiconductor devices, systematically and in progressing detail.For simplicity we have chosen this description for a one-dimensional se- conductorthatpermitsasimpledemonstrationoftheresultsgraphicallywi- out requiring sometimes confusing perspective rendering. In order to clarify the principles involved, the book starts with a hy- thetical model, by assuming simple space charge distributions and deriving their e?ects on ?eld and potential distributions, using the Poisson equation. Itemphasizestheimportantsignrelationsoftheinterreactingvariables,space charge, ?eld, and potential (band edges). It then expands into simple semiconductor models that contain an abrupt nn-junction and gives an example of important space chargelimited currents, + as observed in nn -junctions.

This monograph of Electro-Optical E?ects to Visualize Field- and Current- Distributions in Semiconductors consists of ?ve parts, four of which are based ontheresearchofcadmiumsul?de,wherealargenumberofcontributionswere made between 1958 and the late 1960s to directly observe ?eld and current distributionsandinterprettheirresults.Thevisualizationof?elddistributions was accomplished by using the Franz Keldysh e?ect, and the visualization of currentinhomogeneitiesusestheshiftoftheopticalabsorptionedgebyJoule's heating. The ?fth part deals with a review of the explosively developing ?eld of N- and S-shaped current voltage characteristics causing inhomogeneities and instabilities in ?eld and current distributions. This part of the book was composed by Eckehard Sch. oll of the Technical University in Berlin. A major emphasis is given to the ?rst part of the book in which s- tionary high-?eld domains are described. These domains can be used as an essential tool to determine unambiguously certain semiconductor properties, such as the electron density and its mobility as the function of the actual electric ?eld. It is also helpful to determine changes of the work function and electron a?nities between di?erent materials, such as for electrodes and h- erojunctions. Finally, it gives direct information about certain doping and their spacial pro?le.

This handbook is a compendium giving a comprehensive description of the basics of semiconductor physics relevant to the design and analysis of thin film solar cell materials. It starts from the basics of material science, describing the material and its growth, defect and electrical properties, the basics of its interaction with photons and the involved statistics, proceeding to space charge effects in semiconductors and pn-junctions. Most attention is given to analyze homo- and hetero-junction solar cells using various models and applying the field-of-direction analysis for discussing current voltage characteristics, and helping to discover the involvement of high-field effects in solar cells. The comprehensive coverage of the main topics of - and relating to - solar cells with extensive reference to literature helps scientists and engineers at all levels to reach a better understanding and improvement of solar cell properties and their production. The author is one of the founders of thin film solar cell research.

This handbook is a compendium giving a comprehensive description of the basics of semiconductor physics relevant to the design and analysis of thin film solar cell materials. It starts from the basics of material science, describing the material and its growth, defect and electrical properties, the basics of its interaction with photons and the involved statistics, proceeding to space charge effects in semiconductors and pn-junctions. Most attention is given to analyze homo- and hetero-junction solar cells using various models and applying the field-of-direction analysis for discussing current voltage characteristics, and helping to discover the involvement of high-field effects in solar cells. The comprehensive coverage of the main topics of - and relating to - solar cells with extensive reference to literature helps scientists and engineers at all levels to reach a better understanding and improvement of solar cell properties and their production. The author is one of the founders of thin film solar cell research.