Resonance Effects of Excitons and Electrons


Book Description

This book presents the various types of resonance effects on excitons, biexcitons and the local electronic centers (LEC) in solids, such as paramagnetic and paraelectric resonances on excitons, exciton acoustic resonance at intra- and interband transitions, radio-optical double resonance on excitons, hole-nuclear double resonance on localized biexcitons, ENDOR and acoustic ENDOR on LEC. The criteria for the generation of coherent photons, phonons and magnons by excitons are explained. The interactions of excitons and biexcitons with paramagnetic centers and nuclear spins, the indirect interaction between the PC through a field of excitons as well as the quasienergy spectrum of excitons and spin systems are discussed. It is proved that the interaction of paramagnetic centers with excitons increases the spin relaxation rate of paramagnetic centers in comparison with the case of their interaction with free carriers. The giant magneto-optical effects in semi-magnetic semiconductors are theoretically interpreted. In recent years, a new perspective has been added to these systems and their interactions: They can be used for storing and processing information in the form of quantum bits (qubits), the building blocks of quantum computers. The basics of this emerging technology are explained and examples of demonstration-type quantum computers based on localized spins in solids are discussed.







Excitonic Effects and Bandgap Instabilities in Perovskite Solar Cells


Book Description

Perovskite solar cells are the new hope of next-generation photovoltaic concepts for sustainable energy generation. Regarding their favorable optoelectronic properties, bound electron-hole pairs (so-called excitons) play a significant role and are thoroughly investigated utilizing various spectroscopic methods. Moreover, bandgap instabilities caused by segregation effects in mixed perovskites are analyzed in detail using electroreflectance spectroscopy and structural characterization techniques.




Optical Properties and Applications of Semiconductors


Book Description

Semiconductors with optical characteristics have found widespread use in evolving semiconductor photovoltaics, where optical features are important. The industrialization of semiconductors and their allied applications have paved the way for optical measurement techniques to be used in new ways. Due to their unique properties, semiconductors are key components in the daily employed technologies in healthcare, computing, communications, green energy, and a range of other uses. This book examines the fundamental optical properties and applications of semiconductors. It summarizes the information as well as the optical characteristics and applicability of semiconductors through an in-depth review of the literature. Accomplished experts in the field share their knowledge and examine new developments. FEATURES Comprehensive coverage of all types of optical applications using semiconductors Explores relevant composite materials and devices for each application Addresses the optical properties of crystalline and amorphous semiconductors Describes new developments in the field and future potential applications Optical Properties and Applications of Semiconductors is a comprehensive reference and an invaluable resource for engineers, scientists, academics, and industry R&D teams working in applied physics.




Excess Electrons in Dielectric Media


Book Description

This book provides a comprehensive review of the present knowledge and current problems concerning physical-chemical aspects of the behavior of excess electrons in various media. The book's 13 chapters strike a balance between theoretical and experimental accounts and provide in-depth presentations of specific subjects. Among the several topics discussed in this stimulating volume are primary interactions, transport, and relaxation of excess electrons of a few tens of electron-Volts in various solid and liquid materials; energetics and transport properties of electrons after thermalization in non-polar dielectric liquids; quantum simulation methods; and electron solvation in polar liquids and of excess electrons trapped in polar matrices at low temperature. Applications of these concepts are discussed as well, including hot electron transport in silicon dioxide, the fate of excess electrons created in polar dielectric liquids by photoelectrochemical methods or by cathodic generation, and excess electron production and decay in organic microheterogeneous systems. Researchers, instructors, and engineers working in the radiation sciences, condensed-matter physics, chemical physics, biophysics, photochemistry, and the biochemistry of electron transfer and electrochemistry should consider this book to be an invaluable reference resource.




Electron and Photon Confinement in Semiconductor Nanostructures


Book Description

The purpose of this course was to give an overview of the physics of artificial semiconductor structures confining electrons and photons. It furnishes the background for several applications in particular in the domain of optical devices, lasers, light emitting diodes or photonic crystals. The effects related to the microactivity polaritons, which are mixed electromagnetic radiation-exciton states inside a semiconconductor microactivity are covered. The study of the characteristics of such states shows strong relations with the domain of cavity quantum electrodynamics and thus with the investigation of some fundamental theoretical concepts.




Light-Driven Alignment


Book Description

This book deals with influencing the properties of solids by light-driven electron transport. The theoretical basis of these effects, light-driven ordering and self-organisation, as well as optical motors are presented. With light as a tool, new ways to produce materials are opened.




Raman Spectroscopy


Book Description




Landau Level Spectroscopy


Book Description

Modern Problems in Condensed Matter Sciences, Volume 27.2: Landau Level Spectroscopy focuses on the processes, reactions, methodologies, and approaches involved in condensed matter sciences, including magnetospectroscopy, resonances, electrodynamics, and magnetic fields. The selection first offers information on the magnetospectroscopy of confined semiconductor systems and the magnetophonon effect in two dimensions. Discussions focus on hot-electron magnetophonon resonance, normal resonances, free carrier states, confined impurities, and electron-phonon interaction. The text then takes a look at the energy spectrum and magnetooptics of band-inverting heterojunctions and the electrodynamics of two-dimensional electron systems in high magnetic fields. The publication examines Landau emission and the Shubnikov-de Haas (SdH) effect. Topics include smooth magnetoresistance and SdH effect, Landau level electronic lifetimes, experimental techniques, and Landau emission in III-IV semiconductors. The book then elaborates on a comprehensive review of the experimental aspects of the SdH effect; magnetoimpurity resonances in semiconductor transport; and magnetophonon resonance. The selection is a highly recommended reference for scientists and readers interested in the Landau level spectroscopy.




Primary Photoexcitations In Conjugated Polymers: Molecular Exciton Versus Semiconductor Band Model


Book Description

This volume concentrates on the controversy within the scientific community over how to explain, understand and describe the photophysics/photochemistry of this class of materials.This controvery is of such a fundamental nature that the solution of the problem might be in a unification of the semiconductor and metal physics with the molecular quantum chemistry. Thus, a wide-ranging and comprehensive discussion of this very crucial issue has not been written down yet.This volume brings together the most prominent scientists specializing in this controversial topic. Each contributor addresses the opponents' arguments. After short introductory chapters, the contributors discuss their own speciality area and compare the results with both models and explain their position on why one of the models is more appropriate. Special emphasis is given to comparative discussions with other conjugated molecular systems as well as inorganic semiconductors.