This thesis describes novel devices for the secure identification of objects or electronic systems. The identification relies on the the atomic-scale uniqueness of semiconductor devices by measuring a macroscopic quantum property of the system in question. Traditionally, objects and electronic systems have been securely identified by measuring specific characteristics: common examples include passwords, fingerprints used to identify a person or an electronic device, and holograms that can tag a given object to prove its authenticity. Unfortunately, modern technologies also make it possible to circumvent these everyday techniques. Variations in quantum properties are amplified by the existence of atomic-scale imperfections. As such, these devices are the hardest possible systems to clone. They also use the least resources and provide robust security. Hence they have tremendous potential significance as a means of reliably telling the good guys from the bad.

This book reviews the current state-of-the art of single layer silicene up to thicker silicon nanosheets, and their structure, properties and potential applications. Silicene is a newly discovered material that is one atomic layer think. It is a two-dimensional (2D) nanomaterial that is classified as a nanosheet, which has large lateral dimensions up to micrometres, but thicknesses of only nanometres or less. Silicon nanosheets are currently a very 'hot' area of research. The unique properties and morphology of such materials make them ideal for a variety of applications, including electronic devices, batteries and sensors. 2D nanosheets of silicon can be considered as analogues of graphene. As silicon is already the major component of electronic devices, the significance of nanosheets composed of silicon is that they can be more easily integrated into existing electronic devices. Furthermore, if 2D nanostructured Si can be implemented into such devices, then their size could be reduced into the nano-regime, providing unique properties different from bulk Si that is currently employed. The book is written for researchers and graduate students.

This thesis introduces readers to the type II superstring theories in the AdS5xS5 and AdS4xCP3 backgrounds. Each chapter exemplifies a different computational approach to measuring observables (conformal dimensions of single-trace operators and expectation values of Wilson loop operators) relevant for two supersymmetric theories: the N=4 super Yang-Mills theory and the N=6 Chern-Simons-matter (ABJM) theory. Perturbative techniques have traditionally been used to make quantitative predictions in quantum field theories, but they are only reliable as long as the interaction strengths are weak. The anti-de Sitter/conformal field theory (AdS/CFT) correspondence realizes physicists' dream of studying strongly coupled quantum field theories with "enhanced" symmetries, using the methods provided by string theory. The first part of the thesis sets up the semiclassical quantization of worldsheet sigma-model actions around string solutions of least area in AdS space. This machinery is used to capture quantum corrections at large coupling to next-to-leading and next-to-next-to-leading order by solving the determinants of partial differential operators and by computing Feynman diagrams, respectively. In turn, the second part presents an innovative approach based on Monte Carlo simulations to finite coupling for a lattice-discretized model of the AdS5xS5 superstring action. The thesis focuses on fundamental aspects, as well as on applications previously published by the author, and offers a valuable reference work for anyone interested in the most recent developments in this field.

This thesis sheds important new light on the puzzling properties of Strontium Ruthenate. Using a sophisticated weak-coupling approach, exact within certain limits, it shows that proper treatment of spin-orbit and multi-band effects is crucial to the physics. Based on the results of these calculations, it resolves a crucial, long-standing puzzle in the field: It demonstrates why the experimentally observed time-reversal breaking is not incompatible with the observed lack of measurable edge currents. Lastly, the thesis makes predictions for the properties of the material under uniaxial strain, which are in good agreement with recent experiments -resolving the mystery of the so-called 3K phase, and suggesting the intriguing possibility that under strain the superconductor may become conventional.

This book presents the basics and applications of photonic materials. It focuses on the utility of these devices for sensing, biosensing, and displays. The book includes fundamental aspects with a particular focus on the application of photonic materials. The field of photonic materials is both a burgeoning, and mature field. There are new advances being made on a daily basis, all based on the fundamental roots set by work by those like Ozin, Thomas, Asher, and others.

This book covers different aspects of the physics of iron-based superconductors ranging from the theoretical, the numerical and computational to the experimental ones. It starts from the basic theory modeling many-body physics in Fe-superconductors and other multi-orbital materials and reaches up to the magnetic and Cooper pair fluctuations and nematic order. Finally, it offers a comprehensive overview of the most recent advancements in the experimental investigations of iron based superconductors.

In this book new experimental investigations of properties of Josephson junctions and systems are explored with the help of recent developments in superconductivity. The theory of the Josephson effect is presented taking into account the influence of multiband and anisotropy effects in new superconducting compounds. Anharmonicity effects in current-phase relation on Josephson junctions dynamics are discussed. Recent studies in analogue and digital superconductivity electronics are presented. Topics of special interest include resistive single flux quantum logic in digital electronics. Application of Josephson junctions in quantum computing as superconducting quantum bits are analyzed. Particular attention is given to understanding chaotic behaviour of Josephson junctions and systems. The book is written for graduate students and researchers in the field of applied superconductivity.

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.

This work investigates the energy-level alignment of hybrid inorganic/organic systems (HIOS) comprising ZnO as the major inorganic semiconductor. In addition to offering essential insights, the thesis demonstrates HIOS energy-level alignment tuning within an unprecedented energy range. (Sub)monolayers of organic molecular donors and acceptors are introduced as an interlayer to modify HIOS interface-energy levels. By studying numerous HIOS with varying properties, the author derives generally valid systematic insights into the fundamental processes at work. In addition to molecular pinning levels, he identifies adsorption-induced band bending and gap-state density of states as playing a crucial role in the interlayer-modified energy-level alignment, thus laying the foundation for rationally controlling HIOS interface electronic properties. The thesis also presents quantitative descriptions of many aspects of the processes, opening the door for innovative HIOS interfaces and for future applications of ZnO in electronic devices.

This book presents the proceedings of the International Conference on Recent Trends in Materials and Devices, which was conceived as a major contribution to large-scale efforts to foster Indian research and development in the field in close collaboration with the community of non-resident Indian researchers from all over the world. The research articles collected in this volume - selected from among the submissions for their intrinsic quality and originality, as well as for their potential value for further collaborations - document and report on a wide range of recent and significant results for various applications and scientific developments in the areas of Materials and Devices. The technical sessions covered include photovoltaics and energy storage, semiconductor materials and devices, sensors, smart and polymeric materials, optoelectronics, nanotechnology and nanomaterials, MEMS and NEMS, as well as emerging technologies.

A comprehensive device model considering both spatial distributions of the terahertz field and the field-effect self-mixing factor has been constructed for the first time in the thesis. The author has found that it is the strongly localized terahertz field induced in a small fraction of the gated electron channel that plays an important role in the high responsivity. An AlGaN/GaN-based high-electron-mobility transistor with a 2-micron-sized gate and integrated dipole antennas has been developed and can offer a noise-equivalent power as low as 40 pW/Hz1/2 at 900 GHz. By further reducing the gate length down to 0.2 micron, a noise-equivalent power of 6 pW/Hz1/2 has been achieved. This thesis provides detailed experimental techniques and device simulation for revealing the self-mixing mechanism including a scanning probe technique for evaluating the effectiveness of terahertz antennas. As such, the thesis could be served as a valuable introduction towards further development of high-sensitivity field-effect terahertz detectors for practical applications.

This book introduces electric circuits with variable loads and voltage regulators. It allows to define invariant relationships for various parameters of regime and circuit sections and to prove the concepts characterizing these circuits. The book presents the fundamentals of electric circuits and develops circuit theorems. Generalized equivalent circuits are introduced. Projective geometry is used for the interpretation of changes of operating regime parameters. Expressions of normalized regime parameters and their changes are presented. Convenient formulas for the calculation of currents are given. Parallel voltage sources and the cascade connection of multi-port networks are described. The two-value voltage regulation characteristics of loads with limited power of voltage source is considered. This second edition is extended and contains additional chapters on circuits with non-linear regulation curves, circuits with non-linear load characteristics, concepts of power-source and power-load elements with two-valued characteristics, quasi-resonant voltage converters with self-limitation of current as well as the similarity of characteristics of converters and electronic devices. This book is useful to engineers, researchers and graduate students who are interested in the basic electric circuit theory and the regulation and monitoring of power supply systems.

Devices based on disordered semiconductors have wide applications. It is difficult to imagine modern life without printers and copiers, LCD monitors and TVs, optical disks, economical solar cells, and many other devices based on disordered semiconductors. However, nowadays books that discuss disordered (amorphous, nanocrystalline, microcrystalline) semiconductors focus, as a rule, on either physics of materials or physics of devices that are based on these materials. This book connects characteristic features of the atomic and electronic structures of disordered semiconductors and the device design process on the basis of these materials. Compared with the first edition, this book takes into account the latest developments of disordered semiconductors and devices. It has new sections on the structures of carbon-based amorphous and nanocomposite films and atomic and electronic structures of organic semiconductors.

This book is a comprehensive text on the physics of semiconductors and nanostructures for a large spectrum of students at the final undergraduate level studying physics, material science and electronics engineering. It offers introductory and advanced courses on solid state and semiconductor physics on one hand and the physics of low dimensional semiconductor structures on the other in a single text book. Key Features Presents basic concepts of quantum theory, solid state physics, semiconductors, and quantum nanostructures such as quantum well, quantum wire, quantum dot and superlattice In depth description of semiconductor heterojunctions, lattice strain and modulation doping technique Covers transport in nanostructures under an electric and magnetic field with the topics: quantized conductance, Coulomb blockade, and integer and fractional quantum Hall effect Presents the optical processes in nanostructures under a magnetic field Includes illustrative problems with hints for solutions in each chapter Physics of Semiconductors and Nanostructures will be helpful to students initiating PhD work in the field of semiconductor nanostructures and devices. It follows a unique tutorial approach meeting the requirements of students who find learning the concepts difficult and want to study from a physical perspective.

This book covers the state of the art in the theoretical framework, computational modeling, and the fabrication and characterization of nanoelectronics devices. It addresses material properties, device physics, circuit analysis, system design, and a range of applications. A discussion on the nanoscale fabrication, characterization and metrology is also included. The book offers a valuable resource for researchers, graduate students, and senior undergraduate students in engineering and natural sciences, who are interested in exploring nanoelectronics from materials, devices, systems, and applications perspectives.

This book will address the application of gas phase thin film methods, including techniques such as evaporation, sputtering, CVD, and ALD to the synthesis of materials on nanostructured and high aspect-ratio high surface area materials. We have chosen to introduce these topics and the different application fields from a chronological perspective: we start with the early concepts of step coverage and later conformality in semiconductor manufacturing, and how later on the range of application branched out to include others such as energy storage, catalysis, and more broadly nanomaterials synthesis. The book will describe the ballistic and continuum descriptions of gas transport on nanostructured materials and then will move on to incorporate the impact of precursor-surface interaction. We will finally conclude approaching the subjects of feature shape evolution and the connection between nano and reactor scales and will briefly present different advanced algorithms that can be used to effectively compute particle transport, in some cases borrowing from other disciplines such as radiative heat transfer. The book gathers in a single place information scattered over thirty years of scientific research, including the most recent results in the field of Atomic Layer Deposition. Besides a mathematical description of the fundamentals of thin film growth in nanostructured materials, it includes analytic expressions and plots that can be used to predict the growth using gas phase synthesis methods in a number of ideal approximations. The focus on the fundamental aspects over particular processes will broaden the appeal and the shelf lifetime of this book. The reader of this book will gain a thorough understanding on the coating of high surface area and nanostructured materials using gas phase thin film deposition methods, including the limitations of each technique. Those coming from the theoretical side will gain the knowledge required to model the growth process, while those readers more interested in the process development will gain the theoretical understanding will be useful for process optimization.

Understanding the structural unit of crystalline solids is vital in determining their optical and electronic properties. However, the disordered nature of amorphous semiconductors, where no long-range order is retained, makes it difficult to determine their structure using traditional methods. This book shows how computer modelling can be used to overcome the difficulties that arise in the atomic scale identification of amorphous semiconductors. The book explains how to generate a random structure using computer modelling, providing readers with the techniques to construct realistic material structures. It shows how the optical and electronic properties are related to random structures. Readers will be able to understand the characteristic features of disordered semiconductors. The structural and electronic modifications by photon irradiation are also discussed in detail. This book is ideal for both physicists and engineers working in solid state physics, semiconductor engineering and electrical engineering.

This book provides a theoretical, step-by-step comprehensive explanation of superconductivity for undergraduate and graduate students who have completed elementary courses on thermodynamics and quantum mechanics. To this end, it adopts the unique approach of starting with the statistical mechanics of quantum ideal gases and successively adding and clarifying elements and techniques indispensible for understanding it. They include the spin-statistics theorem, second quantization, density matrices, the Bloch–De Dominicis theorem, the variational principle in statistical mechanics, attractive interaction and bound states. Ample examples of their usage are also provided in terms of topics from advanced statistical mechanics such as two-particle correlations of quantum ideal gases, derivation of the Hartree–Fock equations, and Landau’s Fermi-liquid theory, among others. With these preliminaries, the fundamental mean-field equations of superconductivity are derived with maximum mathematical clarity based on a coherent state in terms of the Cooper-pair creation operator, a quasiparticle field for describing the excitation and the variational principle in statistical mechanics. They have the advantage that the phase coherence due to the Cooper-pair condensation can be clearly seen making the superfluidity comprehensible naturally. Subsequently, they are applied to homogeneous cases to describe the BCS theory for classic s-wave superconductors and its extension to the p-wave superfluidity of 3He. Later, the mean-field equations are simplified to the Eilenberger and Ginzburg–Landau equations so as to describe inhomogeneous superconductivity such as Abrikosov’s flux-line lattice concisely and transparently. Chapters provide the latest studies on the quasiclassical theory of superconductivity and a discovery of p-wave superfluidity in liquid 3He. The book serves as a standard reference for advanced courses of statistical mechanics with exercises along with detailed answers.

This book presents the current knowledge about nonlinear localized travelling excitations in crystals. Excitations can be vibrational, electronic, magnetic or of many other types, in many different types of crystals, as silicates, semiconductors and metals. The book is dedicated to the British scientist FM Russell, recently turned 80. He found 50 years ago that a mineral mica muscovite was able to record elementary charged particles and much later that also some kind of localized excitations, he called them quodons, was also recorded. The tracks, therefore, provide a striking experimental evidence of quodons existence. The first chapter by him presents the state of knowledge in this topic. It is followed by about 18 chapters from world leaders in the field, reviewing different aspects, materials and methods including experiments, molecular dynamics and theory and also presenting the latest results. The last part includes a personal narration of FM Russell of the deciphering of the marks in mica. It provides a unique way to present the science in an accessible way and also illustrates the process of discovery in a scientist's mind.

This thesis describes the construction of a rotatable spin-polarized electron source and its use in spin- and angle-resolved inverse photoemission to investigate the unoccupied electron states of Tl/Si(111)-(1x1) with special emphasis on their spin texture. Towards more efficient electronics - with the electron spin as information carrier: This motto is the motivation for numerous studies in solid state physics that deal with electron states whose spin degeneracy is lifted by spin-orbit interaction. This thesis addresses the spin-orbit-induced spin textures in momentum space in the surface electronic structure of a prototypical Rashba-type hybrid system: heavy metal thallium on semiconducting silicon. For Tl/Si(111)-(1x1), the thallium adlayer provides surface states with strong spin-orbit interaction and peculiar spin-orbit-induced spin textures: spin rotations and spin chirality in momentum space for unoccupied surface states with giant spin splittings. Almost completely out-of-plane spin-polarized valleys in the vicinity of the Fermi level are identified. As the valley polarization is oppositely oriented at specific points in momentum space, backscattering should be strongly suppressed in this system.

This book presents the basics and applications of superconducting magnets. It explains the phenomenon of superconductivity, theories of superconductivity, type II superconductors and high-temperature cuprate superconductors. The main focus of the book is on the application to superconducting magnets to accelerators and fusion reactors and other applications of superconducting magnets. The thermal and electromagnetic stability criteria of the conductors and the present status of the fabrication techniques for future magnet applications are addressed. The book is based on the long experience of the author in studying superconducting materials, building magnets and numerous lectures delivered to scholars. A researcher and graduate student will enjoy reading the book to learn various aspects of magnet applications of superconductivity. The book provides the knowledge in the field of applied superconductivity in a comprehensive way.

This book presents an important technique to process organic photovoltaic devices. The basics, materials aspects and manufacturing of photovoltaic devices with solution processing are explained. Solution processable organic solar cells - polymer or solution processable small molecules - have the potential to significantly reduce the costs for solar electricity and energy payback time due to the low material costs for the cells, low cost and fast fabrication processes (ambient, roll-to-roll), high material utilization etc. In addition, organic photovoltaics (OPV) also provides attractive properties like flexibility, colorful displays and transparency which could open new market opportunities. The material and device innovations lead to improved efficiency by 8% for organic photovoltaic solar cells, compared to 4% in 2005. Both academic and industry research have significant interest in the development of this technology. This book gives an overview of the booming technology, focusing on the solution process for organic solar cells and provides a state-of-the-art report of the latest developments. World class experts cover fundamental, materials, devices and manufacturing technology of OPV technology.

This book underscores the essential principles of photocatalysis and provides an update on its scientific foundations, research advances, and current opinions, and interpretations. It consists of an introduction to the concepts that form the backbone of photocatalysis, from the principles of solid-state chemistry and physics to the role of reactive oxidizing species. Having recognised the organic link with chemical kinetics, part of the book describes kinetic concepts as they apply to photocatalysis. The dependence of rate on the reaction conditions and parameters is detailed, the retrospective and prospective aspects of the mechanism of photocatalysis are highlighted, and the adsorption models, photocatalytic rate expressions, and kinetic disguises are examined. This book also discusses the structure, property, and activity relationship of prototypical semiconductor photocatalysts and reviews how to extend their spectral absorption to the visible region to enable the effective use of visible solar spectrum. Lastly, it presents strategies for deriving substantially improved photoactivity from semiconductor materials to support the latest applications and potential trends.

In this thesis, the author has developed a high-resolution spin-resolved photoemission spectrometer that achieves the world-best energy resolution of 8 meV. The author has designed a new, highly efficient mini Mott detector that has a large electron acceptance angle and an atomically flat gold target to enhance the efficiency of detecting scattered electrons. The author measured the electron and spin structure of Bi thin film grown on a Si(111) surface to study the Rashba effect. Unlike the conventional Rashba splitting, an asymmetric in-plane spin polarization and a tremendous out-of-plane spin component were observed. Moreover, the author found that the spin polarization of Rashba surface states is reduced by decreasing the film thickness, which indicates the considerable interaction of Rashba spin-split states between the surface and Bi/Si interface.

This critical volume examines the different methods used for the synthesis of a great number of photocatalysts, including TiO2, ZnO and other modified semiconductors, as well as characterization techniques used for determining the optical, structural and morphological properties of the semiconducting materials. Additionally, the authors discuss photoelectrochemical methods for determining the light activity of the photocatalytic semiconductors by means of measurement of properties such as band gap energy, flat band potential and kinetics of hole and electron transfer. Photocatalytic Semiconductors: Synthesis, Characterization and Environmental Applications provide an overview of the semiconductor materials from first- to third-generation photocatalysts and their applications in wastewater treatment and water disinfection. The book further presents economic and toxicological aspects in the production and application of photocatalytic materials.