This volume contains the invited papers of the Spring meeting of the Arbeitskreis Festk?rperphysik of the Deutsche Physikalische Gesellschaft, which has been held in Regensburg in the period March 23 - 27, 1998. The meeting has been attended by more than 2800 participants from all areas of solid state physics and other areas of physics as well since this time it has been organized together with the yearly general meeting. The invited and plenary talks as well as the numerous symposia reflected most recent developments in physics. This book covers the current status of the fileds and shows the excitement which has been felt by the speakers when presenting their results.Present status of InGaN-based UV/blue/green LEDs and laser diodes.- Group III-nitride based blue emitters.- Laser processes in group-III nitrides.- Growth and characterization of IIVI semiconductor lasers.- Many-body theory for IIVI semiconductor laser media.- SiC: Polar properties and their influence on technology and devices.- Growth mechanisms of SiC on ?-SiC(0001) prepared by solid-source molecular beam epitaxy.- Si1?x?yGexCy alloys: Growth and properties of a new semiconducting material.- Correlations between microstructure and electronic properties in amorphous carbon based materials.- Characterization of CVD-diamond layers: Electronic states.- Electron ground states in a few-electron quantum dot.- Atomically precise, coupled quantum dots fabricated by cleaved edge overgrowth.- Raman spectroscopy of quantum dots.- Charged excitons in InAs quantum dots.- Charge fluctuations, chaotic trajectories, and the coulomb blockade.- Diode lasers based on quantum dots.- Sonoluminescence: When bubbles glow.- Bloch oscillations in semiconductor superlattices.- Optical properties of localized excitons in nanostructures: Theoretical aspects.- Superradiant exciton-light coupling in semiconductor heterostructuresTheory.- Superradiant exciton/light coupling in semiconductor heterostructuresPart II: Experiments.lSĄ