The aim of this NATO ASI has been to present an up-to-date overview of current areas of interest in amorphous materials, with particular emphasis on electronic properties and device applications. In order to limit the material to a manageable amount, the meeting was concerned almost exclusively with semiconducting materials. This volume should be regarded as a follow-on to the NATO ASI held in Sozopol, Bulgaria in 1996 and published as "Amorphous Insulators and Semiconductors" edited by M.F. Thorpe and M.1. Mitkova (Kluwer Academic Publishers, NATO ASI series, 3 High Technology - Vol. 23). The lectures and seminars fill the gap between graduate courses and research seminars. The lecturers and seminar speakers were chosen as experts in their respective areas, and the lectures and seminars that were given are presented in this volume. During the first week of the meeting, an emphasis was placed on introductory lectures while the second week focused more on research seminars. There were two very good poster sessions that generated a lot of discussion, but these are not reproduced in this volume as the editors wanted to have only larger contributions to make the proceedings more coherent.

Solid state physics after solving so successfully many fundamental problems in perfect or slightly imperfect crystals, tried in recent years to attack problems associated with large disorder with the aim to understand the consequences of the lack of the long-range order. Semiconductors are much more changed by disorder than metals or insulators, and appear to be the most suitable materials for fundamental work. Considerable exploratory work on amorphous and liquid semiconductors was done by the Leningrad School since the early fifties. In recent years, much research in several countries was directed to deepen the understanding of the structural, electronic, optical, vibrational, magnetic and other proper ties of these materials and to possibly approach the present level of under standing of crystalline semiconductors. This effort was stimulated not only by purely scientific interest but also by the possibility of new applications from which memory devices in the general sense are perhaps the most challenging. The research met with serious difficulties which are absent in crystals.