Porous Silicon

By means of electrochemical treatment, crystalline silicon can be permeated with tiny, nanostructured pores that entirely change the characteristics and properties of the material. One prominent example of this can be seen in the interaction of porous silicon with living cells, which can be totally unwilling to settle on smooth silicon surfaces but readily adhere to porous silicon, giving rise to great hopes for such future applications as programmable drug delivery or advanced, braincontrolled prosthetics. Porous silicon research is active in the fields of sensors, tissue engineering, medical therapeutics and diagnostics, photovoltaics, rechargeable batteries, energetic materials, photonics, and MEMS (Micro Electro Mechanical Systems). Written by an outstanding, well-recognized expert in the field, this book provides detailed, step-by-step instructions to prepare and characterize the major types of porous silicon. It is intended for those new to the fi eld. Sampling of topics covered: * Principles of Etching Porous Silicon * Etch Cell Construction and Considerations * Photonic Crystals, Microcavities, and Bragg Stacks Etched in Silicon * Preparation of Free-standing Films and Particles of Porous Silicon * Preparation of Photoluminescent Nanoparticles from Porous Silicon * Preparation of Silicon Nanowires by Electrochemical Etch of Silicon * Surface Modifi cation Chemistry and Biochemistry * Measurement of Optical Properties * Measurement of Pore Size, Porosity, Thickness, Surface Area The whole is backed by a generous use of color photographs to illustrate the described procedures in detail, plus a bibliography of further literature pertinent to a wide range of application fi elds. For materials scientists, chemists, physicists, optical physicists, biomaterials scientists, neurobiologists, bioengineers, and graduate students in those fields, as well as those working in the semiconductor industry.

Due to the recent discovery of the room-temperature visible light emission from porous silicon (P-Si), a great interest in P-Si and related materials has arisen in the last decade of the 20th century. Crystalline (c-) Si, at the heart of integrated circuits, has an indirect band gap of 1.1 eV, which limits its application in optoelectronics. The visible light emitting P-Si may open a new field combining Si integrated technology and optoelectronics. This book is a comprehensive review of the recent research and development of porous silicon. Strong visible photoluminescence (PL) and electroluminescence (EL) from P-Si and other forms of silicon nanocrystallites (nc-Si) are reviewed. Several proposed mechanisms for the PL from porous silicon such as quantum confinement, amorphicity and molecular PL are studied. The following issues are covered: mechanisms for the visible light emission, physical structures, studies of the PL and EL, correlation of structure and optical studies, surface physics and chemistry, relationships among various forms (P-Si, a-Si, µc-Si), device applications, future developments.

Porous Silicon for Biomedical Applications, Second Edition, provides an updated guide to the diverse range of biomedical applications of porous silicon, from biosensing and imaging to tissue engineering and cancer therapy. Across biomedical disciplines, there is an ongoing search for biomaterials that are biocompatible, modifiable, structurally sound, and versatile. Porous silicon possesses a range of properties that make it ideal for a variety of biomedical applications, such as controllable geometry, tunable nanoporous structure, large pore volume/high specific surface area, and versatile surface chemistry. This book provides a fully updated and detailed overview of the range of biomedical applications for porous silicon. Part One offers the reader a helpful insight into the fundamentals and beneficial properties of porous silicon, including thermal properties and stabilization, photochemical and nonthermal chemical modification, protein modification, and biocompatibility. The book then builds on the systematic detailing of each biomedical application using porous silicon, from bioimaging and sensing to drug delivery and tissue engineering. This new edition also includes new chapters on in-vivo assessment of porous silicon, photodynamic and photothermal therapy, micro- and nanoneedles, Raman imaging, cancer immunotherapy, and more. With its acclaimed editor and international team of expert contributors, Porous Silicon for Biomedical Applications, Second Edition, is a technical resource and indispensable guide for all those involved in the research, development, and application of porous silicon and other biomaterials, while providing a comprehensive introduction for students and academics interested in this field. Reviews the fundamental aspects of porous silicon, including the fabrication and unique properties of this useful material. Discusses a broad selection of biomedical applications, offering a detailed insight into the benefits of porous silicon in both research and clinical settings. Includes fully updated content from the previous edition, as well as brand new chapters, covering topics such as porous silicon micro- and nanoneedles, and cancer immunotherapy.

Porous Silicon Carbide and Gallium Nitride: Epitaxy, Catalysis, and Biotechnology Applications presents the state-of-the-art in knowledge and applications of porous semiconductor materials having a wide band gap. This comprehensive reference begins with an overview of porous wide-band-gap technology, and describes the underlying scientific basis for each application area. Additional chapters cover preparation, characterization, and topography; processing porous SiC; medical applications; magnetic ion behavior, and many more

These proceedings represent the most recent progress in the field of porous silicon. Several papers present results in which the influence of the formation parameters on the structural and optical properties has been investigated. Further topics dealt with include: the influence of light during the formation process on the photoluminescence behaviour; fundamental mechanism of the photoluminescence; the electroluminescence of porous silicon; applications based on porous silicon; charge carrier transport.

Porous silicon has been the focus of much research activity in recent years, in view of its luminescence, which may enable light emitting devices to be integrated with silicon chips. This work comprises over 50 commissioned essays on the subject from scientists in Europe, America and Japan .

Porous silicon is rapidly attracting increasing interest in various fields, including optoelectronics, microelectronics, photonics, medicine, chemistry, biosensing, and energy. Porous Silicon: Formation and Properties fills a gap in the literature of the field today, providing a thorough introduction to current knowledge of the formation, processing, and properties of porous silicon. It also analyzes present and potential applications of porous silicon in technology, including various devices. With contributions from an international team of well-known experts, this book presents the most recent progress in the field of porous silicon. Focused chapters cover the fundamentals of silicon porosification, the qualities of porous silicon, including its electrical, luminescent, optical, and thermal properties, and the processing of porous silicon for use in the technology of other fields. It also gives valuable insights on what can be expected from the field in the near future. The book includes extensive references to recently published literature on the subject, allowing for deeper exploration of information on the porosification process, designing porous silicon-based technology, and improving performance of devices fabricated using porous silicon. It is an indispensable addition to the library of any scientist or technician involved or interested in the research, development, and application of porous silicon.

This volume provides a comprehensive review of the experimental and theoretical aspects of the optical and transport properties of nanoporous silicon, their relation to the microscopic structure of nanocrystals, and the application of porous silicon in optical devices. As porous silicon is an ideal substance for the modelling of optical processes in nanocrystalline materials, this volume also is an excellent reference source on the more general subject of the structural and optical properties of nanocrystalline semiconductors.