This book contains the proceedings of the NATO Advanced Research Workshop on "Resonant Tunneling in Semiconductors: Physics and Applications", held at Escorial, Spain, on May 14-18, 1990. The tremendous growth in the past two decades in the field of resonant tunneling in semiconductor heterostructures has followed, if not outpaced, the expansion wit nessed in quantum structures in general. Resonant tunneling shares also the multi disciplinary nature of that broad area, with an emphasis on the underlying physics but with a coverage of material systems on the one end and device applications on the other. Indeed, that resonant tunneling provides great flexibility in terms of materials and configurations and that it is inherently a fast process with obvious device impli cations by the presence of a negative differential resistance have contributed to the unrelenting interest in this field. These proceedings consist of 49 refereed articles; they correspond to both invited and contributed talks at the workshop. Because of the intertwinning nature of the subject matter, it has been difficult to subdivide them in well-defined sections. Instead, they are arranged in several broad categories, meant to serve only as guidelines of emphasis on different topics and aspects. The book starts with an introduction to res onant tunneling by providing a perspective of the field in the first article. This is fol lowed by discussions of different material systems with various band-structure effects.

II-VI Semiconductor Materials and Their Applications deals with II-VI compound semiconductors and the status of the two areas of current optoelectronics applications: blue-green emitters and IR detectors. Specifically, the growth, charactrtization, materials and device issues for these two applications are described. Emphasis is placed on the wide bandgap emitters where much progress has occurred recently.The book also presents new directions that have potential, future applications in optoelectronics for II-VI materials. In particular, it discusses the status of dilute magnetic semiconductors for mango-optical and electromagnetic devices, nonlinear optical properties, photorefractive effects and new materials and physics phenomena, such as self-organized, low-dimensional structures.II_VI Semiconductor Materials and Their Applications is a valuable reference book for researchers in the field as well as a textbook for materials science and applied physics courses.

This book originated out of a desire to provide students with an instrument which might lead them from knowledge of elementary classical and quantum physics to moderntheoreticaltechniques for the analysisof electrontransport in semiconductors. The book is basically a textbook for students of physics, material science, and electronics. Rather than a monograph on detailed advanced research in a speci?c area, it intends to introduce the reader to the fascinating ?eld of electron dynamics in semiconductors, a ?eld that, through its applications to electronics, greatly contributed to the transformationof all our lives in the second half of the twentieth century, and continues to provide surprises and new challenges. The ?eld is so extensive that it has been necessary to leave aside many subjects, while others could be dealt with only in terms of their basic principles. The book is divided into ?ve major parts. Part I moves from a survey of the fundamentals of classical and quantum physics to a brief review of basic semiconductor physics. Its purpose is to establish a common platform of language and symbols, and to make the entire treatment, as far as pos- ble, self-contained. Parts II and III, respectively, develop transport theory in bulk semiconductors in semiclassical and quantum frames. Part IV is devoted to semiconductor structures, including devices and mesoscopic coherent s- tems. Finally, Part V develops the basic theoretical tools of transport theory within the modern nonequilibrium Green-function formulation, starting from an introduction to second-quantization formalism.

Introducing up-to-date coverage of research in electron field emission from nanostructures, Vacuum Nanoelectronic Devices outlines the physics of quantum nanostructures, basic principles of electron field emission, and vacuum nanoelectronic devices operation, and offers as insight state-of-the-art and future researches and developments. This book also evaluates the results of research and development of novel quantum electron sources that will determine the future development of vacuum nanoelectronics. Further to this, the influence of quantum mechanical effects on high frequency vacuum nanoelectronic devices is also assessed. Key features: • In-depth description and analysis of the fundamentals of Quantum Electron effects in novel electron sources. • Comprehensive and up-to-date summary of the physics and technologies for THz sources for students of physical and engineering specialties and electronics engineers. • Unique coverage of quantum physical results for electron-field emission and novel electron sources with quantum effects, relevant for many applications such as electron microscopy, electron lithography, imaging and communication systems and signal processing. • New approaches for realization of electron sources with required and optimal parameters in electronic devices such as vacuum micro and nanoelectronics. This is an essential reference for researchers working in terahertz technology wanting to expand their knowledge of electron beam generation in vacuum and electron source quantum concepts. It is also valuable to advanced students in electronics engineering and physics who want to deepen their understanding of this topic. Ultimately, the progress of the quantum nanostructure theory and technology will promote the progress and development of electron sources as main part of vacuum macro-, micro- and nanoelectronics.

This volume contains contributions presented at the 12th International Conference on High Magnetic Fields in Semiconductor Physics. In order to give an overview, 37 lecturers not only reviewed the latest results in their field, but also gave a general introduction. The rapid development of semiconductor physics and technology during the last few years has resulted in an extensive application of high magnetic fields in both fundamental and applied research; more than 160 contributed papers were presented as posters.Sixteen years after its discovery, the quantum Hall effect (QHE) is still a subject of high activity. Many new results on the fractional QHE were presented; in addition to 6 invited papers, there were 43 contributions. Another field of high activity is magneto-optics, and 49 posters were presented. Magnetotransport also turned out to be of high interest, and magnetic semiconductors played a prominent role at the conference, too.Without doubt, the availability of superconducting magnets in most laboratories contributed to the growth of semiconductor physics in high magnetic fields. Because not all experiments can be performed in fields up to 10 or 15 teslas, high magnetic field laboratories offering larger fields are indispensable. There were reports from four laboratories on present work going on at these installations.

A comprehensive account of the latest developments in the rapidly expanding area of Semiconductor Technology. Main topics covered include real space transfer/heterostructures, ultrafast studies, optical studies, transport theory, devices, ballistic transport, scattering processes and hot phonons, tunnelling, far infrared and magnetic field studies and impact ionization/noise/chaos. Other aspects include the use of femtosecond lasers in investigating transient hot carrier effects on femtosecond timescales, magnetotransport and carrier-carrier interactions.

A NATO workshop on "The Properties of Impurity States in Semiconductor Superlattices" was held at the University of Essex, Colchester, United Kingdom, from September 7 to 11, 1987. Doped semiconductor superlattices not only provide a unique opportunity for studying low dimensional electronic behavior, they can also be custom-designed to exhibit many other fascinating el~ctronic properties. The possibility of using these materials for new and novel devices has further induced many astonishing advances, especially in recent years. The purpose of this workshop was to review both advances in the state of the art and recent results in various areas of semiconductor superlattice research, including: (i) growth and characterization techniques, (ii) deep and shallow im purity states, (iii) quantum well states, and (iv) two-dimensional conduction and other novel electronic properties. This volume consists of all the papers presented at the workshop. Chapters 1-6 are concerned with growth and characterization techniques for superlattice semiconductors. The question of a-layer is also discussed in this section. Chapters 7-15 contain a discussion of various aspects of the impurity states. Chapters 16- 22 are devoted to quantum well states. Finally, two-dimensional conduction and other electronic properties are described in chapters 23-26.

E se non che di cid son vere prove A nd were it not for the true evidence Per piti e piti autori, che sa, ra. nno Of many authors who will be Per i miei versi nominati altrove, Mentioned elsewhere in my rhyme Non presterei alla penna 10. mana I would not lend my hand to the pen Per nota1' cid ch'io vidi, can temenza And describe my observations, for fear ehe non fosse do. altri casso e van 0; That they would be rejected and in vane; Mala lor chiara. e vera. esperienza But these authors' clear and true experience Mi assicura. nel dir, come persone Encourages me to report, since they Degne di fede ad ogni gra. n sentenza. Should always be trusted for their word. [From" Dittamondo", by Fazio degli UbertiJ Heterojunction interfaces, the interfaces between different semiconducting materi als, have been extensively explored for over a quarter of a century. The justifica tion for this effort is clear - these interfaces could become the building blocks of lllany novel solid-state devices. Other interfaces involving semiconductors are al ready widely used in technology, These are, for example, metal-semiconductor and insulator-semiconductor junctions and hOll1ojunctions. In comparison, the present applications of heterojunction int. erfaces are limited, but they could potentially becOlne lnuch lllore ext. ensive in the neal' future. The path towards the widespread use of heterojunctions is obstructed by several obstacles

Bridging the gap between a general solid-state physics textbook and research articles, the renowned authors provide detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors. Their approach is a physical and intuitive one, rather than formal and pedantic. This textbook has been written with both students and researchers in mind, and the authors therefore present theories to explain experimental results. Throughout, the emphasis is on understanding the physical properties of Si, and similar tetrahedrally coordinated semiconductors, with explanations based on physical insights. Each chapter is enriched by an extensive collection of tables of material parameters, figures and problems -- many of the latter 'lead students by the hand' to arrive at the results.