Physics of Thin Films is one of the longest running continuing series in thin film science, consisting of 25 volumes since 1963. The series contains quality studies of the properties of various thin films materials and systems. In order to be able to reflect the development of today's science and to cover all modern aspects of thin films, the series, starting with Volume 20, has moved beyond the basic physics of thin films. It now addresses the most important aspects of both inorganic and organic thin films, in both their theoretical and their technological aspects.