A self-consistent model of point defects requires a reliable connection with the experimentally deduced structural, spectroscopic and thermodynamic properties of the defect centres, to allow their unambiguous identification. This book focuses on the properties of defects in group IV semiconductors and seeks to clarify whether full knowledge of their chemical nature can account for several problems encountered in practice. It is shown how difficult the fulfilment of self-consistency conditions can be, even today, after more than four decades of dedicated research work, especially in the case of compound semiconductors, such as SiC, but also in the apparently simple cases of silicon and germanium. The reason for this is that the available microscopic models do not yet account for defect interactions in real solids.

This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theoretical paths. - Expert contributors - Reviews of the most important recent literature - Clear illustrations - A broad view, including examination of defects in different semiconductors

Defects in semiconductors have been studied for many years, in many cases with a view toward controlling their behaviour through various forms of “defect engineering”. For example, in the bulk, charging significantly affects the total concentration of defects that are available to mediate phenomena such as solid-state diffusion. Surface defects play an important role in mediating surface mass transport during high temperature processing steps such as epitaxial film deposition, diffusional smoothing in reflow, and nanostructure formation in memory device fabrication. “Charged Defects in Semiconductors” details the current state of knowledge regarding the properties of the ionized defects that can affect the behaviour of advanced transistors, photo-active devices, catalysts, and sensors. Features: group IV, III-V, and oxide semiconductors; intrinsic and extrinsic defects; and, point defects, as well as defect pairs, complexes and clusters.

The precedent book with the title "Structural Analysis of Point Defects in Solids: An introduction to multiple magnetic resonance spectroscopy" ap peared about 10 years ago. Since then a very active development has oc curred both with respect to the experimental methods and the theoretical interpretation of the experimental results. It would therefore not have been sufficient to simply publish a second edition of the precedent book with cor rections and a few additions. Furthermore the application of the multiple magnetic resonance methods has more and more shifted towards materials science and represents one of the important methods of materials analysis. Multiple magnetic resonances are used less now for "fundamental" studies in solid state physics. Therefore a more "pedestrian" access to the meth ods is called for to help the materials scientist to use them or to appreciate results obtained by using these methods. We have kept the two introduc tory chapters on conventional electron paramagnetic resonance (EPR) of the precedent book which are the base for the multiple resonance methods. The chapter on optical detection of EPR (ODEPR) was supplemented by sections on the structural information one can get from "forbidden" transitions as well as on spatial correlations between defects in the so-called "cross relaxation spectroscopy". High-field ODEPR/ENDOR was also added. The chapter on stationary electron nuclear double resonance (ENDOR) was supplemented by the method of stochastic END OR developed a few years ago in Paderborn which is now also commercially available.

From its early beginning before the war, the field of semiconductors has developped as a classical example where the standard approximations of 'band theory' can be safely used to study its interesting electronic properties. Thus in these covalent crystals, the electronic structure is only weakly coupled with the atomic vibrations; one-electron Bloch functions can be used and their energy bands can be accurately computed in the neighborhood of the energy gap between the valence and conduction bands; nand p doping can be obtained by introducing substitutional impurities which only introduce shallow donors and acceptors and can be studied by an effective-mass weak-scattering description. Yet, even at the beginning, it was known from luminescence studies that these simple concepts failed to describe the various 'deep levels' introduced near the middle of the energy gap by strong localized imperfections. These imperfections not only include some interstitial and many substitutional atoms, but also 'broken bonds' associated with surfaces and interfaces, dis location cores and 'vacancies', i.e., vacant iattice sites in the crystal. In all these cases, the electronic structure can be strongly correlated with the details of the atomic structure and the atomic motion. Because these 'deep levels' are strongly localised, electron-electron correlations can also playa significant role, and any weak perturbation treatment from the perfect crystal structure obviously fails. Thus, approximate 'strong coupling' techniques must often be used, in line' with a more chemical de scription of bonding.

Point defects in semiconductors have been and will continue to be relevant for applications. Shallow defects realize transistors, which power the modern age of information, and in the not-too-distant future, deep-level defects could provide the foundation for a revolution in quantum information processing. Deep-level defects (in particular color centers) are also of interest for other applications such as a single photon emitter, especially one that emits at 1550 nm, which is the optimal frequency for long-range communication via fiber optics. First-principle calculations can predict the energies and optical properties of point defects. I performed extensive convergence tests for magneto-optical properties, such as zero phonon lines, hyperfine coupling parameters, and zero-field splitting for the four different configurations of the divacancy in 4H-SiC. Comparing the converged results with experimental measurements, a clear identification of the different configurations was made. With this approach, I also identified all configurations for the silicon vacancy in 4H-SiC as well as the divacancy and silicon vacancy in 6H-SiC. The same method was further used to identify two additional configurations belonging to the divacancy present in a 3C stacking fault inclusion in 4H-SiC. I extended the calculated properties to include the transition dipole moment which provides the polarization, intensity, and lifetime of the zero phonon lines. When calculating the transition dipole moment, I show that it is crucial to include the self-consistent change of the electronic orbitals in the excited state due to the geometry relaxation. I tested the method on the divacancy in 4H-SiC, further strengthening the previous identification and providing accurate photoluminescence intensities and lifetimes. Finding stable point defects with the right properties for a given application is a challenging task. Due to the vast number of possible point defects present in bulk semiconductor materials, I designed and implemented a collection of automatic workflows to systematically investigate any point defects. This collection is called ADAQ (Automatic Defect Analysis and Qualification) and automates every step of the theoretical process, from creating defects to predicting their properties. Using ADAQ, I screened about 8000 intrinsic point defect clusters in 4H-SiC. This thesis presents an overview of the formation energy and the most relevant optical properties for these single and double point defects. These results show great promise for finding new color centers suitable for various quantum applications.

Dopants and Defects in Semiconductors covers the theory, experimentation, and identification of impurities, dopants, and intrinsic defects in semiconductors. The book fills a crucial gap between solid-state physics and more specialized course texts. The authors first present introductory concepts, including basic semiconductor theory, defect classifications, crystal growth, and doping. They then explain electrical, vibrational, optical, and thermal properties. Moving on to characterization approaches, the text concludes with chapters on the measurement of electrical properties, optical spectroscopy, particle-beam methods, and microscopy. By treating dopants and defects in semiconductors as a unified subject, this book helps define the field and prepares students for work in technologically important areas. It provides students with a solid foundation in both experimental methods and the theory of defects in semiconductors.

Semiconductor science and technology is the art of defect engineering. The theoretical modeling of defects has improved dramatically over the past decade. These tools are now applied to a wide range of materials issues: quantum dots, buckyballs, spintronics, interfaces, amorphous systems, and many others. This volume presents a coherent and detailed description of the field, and brings together leaders in theoretical research. Today's state-of-the-art, as well as tomorrow’s tools, are discussed: the supercell-pseudopotential method, the GW formalism,Quantum Monte Carlo, learn-on-the-fly molecular dynamics, finite-temperature treatments, etc. A wealth of applications are included, from point defects to wafer bonding or the propagation of dislocation.

Silicon (Si) technologies provide an excellent platform for the design of microsystems where photonic and microelectronic functionalities are monolithically integrated on the same substrate. In recent years, a variety of passive and active Si photonic devices have been developed, and among them, photodetectors have attracted particular interest from the scientific community. Si photodiodes are typically designed to operate at visible wavelengths, but, unfortunately, their employment in the infrared (IR) range is limited due to the neglectable Si absorption over 1100 nm, even though the use of germanium (Ge) grown on Si has historically allowed operations to be extended up to 1550 nm. In recent years, significant progress has been achieved both by improving the performance of Si-based photodetectors in the visible range and by extending their operation to infrared wavelengths. Near-infrared (NIR) SiGe photodetectors have been demonstrated to have a “zero change” CMOS process flow, while the investigation of new effects and structures has shown that an all-Si approach could be a viable option to construct devices comparable with Ge technology. In addition, the capability to integrate new emerging 2D and 3D materials with Si, together with the capability of manufacturing devices at the nanometric scale, has led to the development of new device families with unexpected performance. Accordingly, this Special Issue of Micromachines seeks to showcase research papers, short communications, and review articles that show the most recent advances in the field of silicon photodetectors and their respective applications.

Praise for the First Edition "The book goes beyond the usual textbook in that it provides more specific examples of real-world defect physics ... an easy reading, broad introductory overview of the field" ?Materials Today "... well written, with clear, lucid explanations ..." ?Chemistry World This revised edition provides the most complete, up-to-date coverage of the fundamental knowledge of semiconductors, including a new chapter that expands on the latest technology and applications of semiconductors. In addition to inclusion of additional chapter problems and worked examples, it provides more detail on solid-state lighting (LEDs and laser diodes). The authors have achieved a unified overview of dopants and defects, offering a solid foundation for experimental methods and the theory of defects in semiconductors. Matthew D. McCluskey is a professor in the Department of Physics and Astronomy and Materials Science Program at Washington State University (WSU), Pullman, Washington. He received a Physics Ph.D. from the University of California (UC), Berkeley. Eugene E. Haller is a professor emeritus at the University of California, Berkeley, and a member of the National Academy of Engineering. He received a Ph.D. in Solid State and Applied Physics from the University of Basel, Switzerland.