With the continuing trend towards reduction of electronic device dimensions into the nanometer regime, the importance of controlling defects, in the bulk material, as well as within layers and at interfaces, becomes more significant. An important aspect of future nanoelectronics is the compatibility to established silicon technologies. A typical example is the integration of SiGe layers into silicon technology since this material offers interesting improvements when compared to the other semicondutor materials. In addition, the possibility of high-frequency and optoelectronic applications are indicated in this book. It features the proceedings of the Fifth International Autumn Meeting, GADEST '93. Due to the current importance of fundamental research, as well as practical applications, the topic of Si/SiGe heterostructures was given special attention in the programme of the 1992 meeting.