Theoretical Studies of Defects, Impurities, and Complexes in Semiconductors

Abstract

ABSTRACTTheoretical studies of microscopic properties of localized defects, impurities, and complexes in semiconductors have greatly progressed in the past decade. Theory has advanced beyond “point” defects to include lattice relaxations and distortions, interactions between defects, complex formation, and even some extended structures. Vibrational frequencies, hyperfine parameters, and other measurable quantities are being calculated from first principles. Both the one-effective-particle density-functional approach and the all-electron Hartree-Fock methods are able to predict a variety of microscopic properties of defects at or near the ab initio level. However, despite the progress achieved, theoretical descriptions only approximate the real world. In this paper, an overview is given of the way these calculations are done and of the main approximations involved. Although some of them will be eliminated by progress in computer technology, other problems such as electron correlation or excited states are likely to require new thinking.