Theory of defects in solids. Electronic structure of defects in insulators and semiconductors (Q2741548)

This classic book first published in 1975 has encyclopaedic character and so far does not lose its great value to all interested in the basic aspects of defects in solids. It is an excellent work which covers both theoretical and experimental bases of the subject. Of course, modern computer technique allows to obtain numerous interesting quantitative results related to the description of defects in solids. Nevertheless, very many qualitative results and theoretical approaches presented in the book keep their value and actuality. In total, the author concentrates himself on the electronic properties of defects which are stressed. Optical and spin-resonance properties are discussed at length, the dynamics of lattices with defects in less detail. Defect production and mechanical properties are largely ignored. NEWLINENEWLINENEWLINEThe book is divided into four main parts. The first part discusses those aspects of perfect crystals which are relevant to the defect systems treated later. The opening chapter defines notation, states essential assumptions, asserts without proof results which are needed later. Namely, in detail the next issues are considered: the geometrical properties of the important crystal types; the electronic structure of the perfect lattice; and the adiabatic, harmonic and dipole approximations in conventional lattice dynamics. The main objective of the second part is the electronic structure of isolated defects. First, it is presented the effective-mass theory. The central result is that often the eigenvalues of a system consisting of one electron plus filled bands could be found by solving an equation for a single particle moving in the field of the difference between the actual potential and the perfect-lattice potential. Then, the Green's function methods and their application to different model states are considered. The more flexibe variational methods, which are, in particular, adequate for strongly-bound centres, are then developed. The survey of molecular methods and correspondent approximations in the context of defect theory completes the lot of models and theoretical methods. The second part is finished by consideration of the lattice distortion due to defects. Special attention is paid to how the atomic displacements can be calculated. The general results which usually refer to bound states are collected in a separate chapter. NEWLINENEWLINENEWLINEThe third part presents different properties of defects, methods of their calculation and observation. The first chapter presents all the totality of optical properties and accompanying processes connected with defects. Then, the author discusses phenomena which result from the modification of the lattice dynamics by the imperfection, due to the presence of a defect in a lattice, which affects the phonon modes and their frequencies. Important cosideration is devoted to the response of defects to external (magnetic, electric or stress) fields, in determining its symmetry and in describing properties like the electron-lattice interaction. Next, on the base of the electron spin resonance method the calculation of the most important parameters of defects is outlined in terms of the defect-electron energy levels and eigenfuctions. The parameters of the spin Hamiltonian -- the connecting link between experiment and theory -- are calculated in terms of the defect wavefunction. The third part is finished by a discussion of the processes accompanying the interaction of free carriers with defects and the important non-radiative transitions between bound states. NEWLINENEWLINENEWLINEThe final part presents a comparison of the theory with experiments. First, the author considers intrinsic defects in ionic crystals, beginning from F-centres in which an electron is trapped at an anion vacancy. Next, the case of two trapped defect electrons or holes is studied. Important generalizations, namely R-centre consisting of three nearest-neighbour F-centres in an alkali-halide crystal, Vk-centre being the self-trapped hole in an ionic crystal, intrinsic interstitials, hydrogen, and defects giving rise to low-frequency resonances in ionic crystals are discussed, too. Then, in detail the following defects are considered: the transition-metal ions in crystals; the shallow donors and acceptors in semiconductors; isoelectronic impurities; dipolar systems and donor-acceptor pairs; bound excitons; and, finally, vacancy in valence crystals. NEWLINENEWLINENEWLINEIn total, this book will be very useful to a wide range of researchers and graduate students interested in solid state science, both to theorists who want to relate their own work to the many previous calculations and to experimentalists who want to know about present theories.