This completely revised volume reflects the revolutionary changes that have taken place in the field of semiconductor physics and technology in the last twenty years. It provides an introduction and background to the many fascinating properties and applications of quantified semiconductor structures. Papers on surface properties, which are of great importance, occupy half of the volume, as a necessary preamble to the quantified semiconductors structure. The volume opens with a discussion on different aspects of the optical properties of semiconductor surfaces that are related to the creation and annihilation of elementary excitations such as phonons, magnons, plasmons and excitons. Further chapters deal with subjects such as photoemission, infrared spectroscopy, intraband optical properties of low-dimensional semiconductor systems and modulation spectroscopy of semiconductors and semiconductor microstructures.