This is a special issue of ECS Transactions published by ECS in memory of Volker Lehmann and Vitali Parkhutik, two key scientists in the field of porous semiconductors who recently passed away. Topics in this issue aim at a more detailed understanding of growth mechanisms and the physical and chemical properties of all types of porous semiconductors. The papers address research in the various sub-fields of porous semiconductors such as semiconductor electrochemistry, deposition into pores, matrix materials, optical spectroscopy and transdisciplinary approaches to the topic as well as work relevant to the formation of advanced materials such as, for example, porous silicon, matrix composites and nanoclusters and their applications such as chemical and biological sensors.

Porous Semiconductors: Optical Properties and Applications provides an examination of porous semiconductor materials. Beginning with a description of the basic electrochemistry of porous semiconductors and the different kinds of porous semiconductor materials that can be fabricated, the book moves on to describe the fabrication processes used in the production of porous semiconductor optical components. Concluding the text, a number of optical components based on porous semiconductor materials are discussed in depth. Porous Semiconductors: Optical Properties and Applications provides a thorough grounding in the design, fabrication and theory behind the optical applications of porous semiconductor materials for graduate and undergraduate students interested in optics, photonics, MEMS, and material science. The book is also a valuable reference for scientists, researchers, and engineers in the field of optics and materials science.

Silicon has been and will most probably continue to be the dominant material in semiconductor technology. Although the defect-free silicon single crystal is one of the best understood systems in materails science, its electrochemistry to many people is still a kind of "alchemy". This view is partly due to the interdisciplinary aspects of the topic: Physics meets chemistry at the silicon-electrolyte interface. This book gives a comprehensive overview of this important aspect of silicon technology as well as examples of applications ranging from photonic crystals to biochips. It will serve materials scientists as well as engineers involved in silicon technology as a quick reference with its more than 150 technical tables and diagrams and ca. 1000 references cited for easy access of the original literature.

The papers included in this issue of ECS Transactions were originally presented in the symposia ¿Tutorials in Nanotechnology: Focus on Luminescence and Display Materials¿, ¿Luminescence and Energy Efficiency¿, and ¿ Physics and Chemistry of Luminescence and Display Materials¿ held during the 218th meeting of The Electrochemical Society, in Las Vegas, Nevada, from October 10 to 15, 2010.