The nonlinear behavior of nitrogen and the passivation effect of hydrogen in dilute nitrides open the way to the manufacture of a new class of nanostructured devices with in-plane variation of the optical band gap. This book addresses the modifications of the electronic structure and of the optical and structural properties induced in these technologically important semiconductors by atomic hydrogen irradiation.

The book comprises discussions on experimental results from several techniques, enriched by state-of-the-art theoretical studies aimed at clarifying the origin of hydrogenation effects that lead to the discovery of specific nitrogen-hydrogen complexes. It presents techniques, such as infrared absorption spectroscopy, synchrotron radiation, and nuclear reaction analysis, which have indeed been crucial for addressing the physical origin of hydrogenation effects and their role in fine structural characterization.

The book is not a simple assembly of the contributions of different groups on the subject; it rather tells the complete story of the amazing effects of hydrogen irradiation from the first observations to the discovery of their origin and to potential technology transfer. The primary scope of the book is to guide PhD students and new scientists into the field and to inspire similar analysis approaches in other fields.

Gianluca Ciatto received his MS in physics from the University of Bologna, Italy, in 2000 and his PhD in physics (condensed matter and synchrotron radiation) from the Université Joseph Fourier in Grenoble, France, in 2004. After a three-year postdoctoral position at the European Synchrotron Radiation Facility (ESRF), he joined in 2007 the French national synchrotron facility SOLEIL (Paris area) as a permanent research staff member. There, at the beamline SIRIUS, he is in charge of the research line devoted to the study of surfaces, interfaces, and nanostructures of semiconductors and magnetic materials. His research interests focus on understanding the structure of defects and complexes in semiconductors, mainly through the application of synchrotron radiation techniques. In particular, Dr. Ciatto is interested in III-V semiconductors for optoelectronics and solar cell applications and in dilute magnetic semiconductors and oxides. He has been working for 15 years on the structural effects of hydrogenation on dilute nitride semiconductors. He is author or coauthor of 50 refereed publications, mostly in the field of semiconductor materials and applied physics, and of two book chapters.