Wide direct band gap gallium nitride (GaN) semiconductor has received significant attention as an ideal material for various applications in the optoelectronic devices. One major use of GaN is the development of energy-efficient solid state light-emitting diodes. Currently, most commercially available GaN semiconductor are produced through advanced deposition techniques which involve sophisticated technologies and are relatively expensive and complicated to setup. As an alternative, the sol-gel spin coating method, which is relatively simpler, cheaper, safer, and more scalable was proposed. In this book, the process route and recipe for producing highly c-oriented crystalline GaN thin films via the sol-gel spin coating approach were described in detail. Some insights into the factors affecting the surface morphology as well as structural and optical properties of the deposited films were presented. Eventually, this book could inspire further studies into the development of low-cost GaN thin films.

Photoelectrochemical (PEC) etching is a simple and inexpensive wet etching approach that is widely used to fabricate porous gallium nitride (GaN) thin films. However, many fundamental issues on the etching mechanism and the optical response of the fabricated porous structure still remain unclear. In this book, PEC etched porous GaN thin films with a variety of morphologies such as circular, hexagonal, leaf like-, and honeycomb-like patterns were described in detail. The effects of semiconductor types, etching voltage and etching duration on the surface morphology and the optical response of the fabricated porous structure were discussed. Attenuated total reflection method which is very sensitive to the surface layer of the porous GaN was applied to extract the carrier concentration, porosity, and layer thicknesses or the porous layer. Through this book, a better understanding of the PEC etching of the porous GaN can be obtained.

The sol-gel method is a powerful route of synthesis used worldwide. It produces bulk, nano- and mesostructured sol-gel materials, which can encapsulate metallic and magnetic nanoparticles, non-linear azochromophores, perovskites, organic dyes, biological molecules, etc.. This can have interesting applications for catalysis, photocatalysis; drug delivery for treatment of neurodegenerative diseases such as cancer, Parkinson's and Azheimer's. In this book, valuable contributions related to novel materials synthesized by the sol-gel route are provided. The effect of the sol-gel method to synthesize these materials with potential properties is described, and how the variation of the parameters during the synthesis influences their design and allows to adjust their properties according to the desired application is discussed.

Annotation Provides background and fundamentals and evaluates present technology. Main topics are thin films in optical, mechanical, and electrical applications; fibers in refractories, composite reinforcement, and thermal insulation; and special applications such as preforms, microballoons, and electronics. Articles are grouped under chemistry and phase transformations; coatings, thin films, and surface treatment; continuous, discontinuous, and woven fibers; monoliths, shapes, and preforms; and special applications. Annotation(c) 2003 Book News, Inc., Portland, OR (booknews.com)

This completely updated and expanded second edition stands as a comprehensive knowledgebase on both the fundamentals and applications of this important materials processing method. The diverse, international team of contributing authors of this reference clarify in extensive detail properties and applications of sol-gel science and technology as it pertains to the production of substances, active and non-active, including optical, electronic, chemical, sensor, bio- and structural materials. Essential to a wide range of manufacturing industries, the compilation divides into the three complementary sections: Sol-Gel Processing, devoted to general aspects of processing and recently developed materials such as organic-inorganic hybrids, photonic crystals, ferroelectric coatings, and photocatalysts; Characterization of Sol-Gel Materials and Products, presenting contributions that highlight the notion that useful materials are only produced when characterization is tied to processing, such as determination of structure by NMR, in-situ characterization of the sol-gel reaction process, determination of microstructure of oxide gels, characterization of porous structure of gels by the surface measurements, and characterization of organic-inorganic hybrid; and Applications of Sol-Gel Technology, covering applications such as the sol-gel method used in processing of bulk silica glasses, bulk porous gels prepared by sol-gel method, application of sol-gel method to fabrication of glass and ceramic fibers, reflective and antireflective coating films, application of sol-gel method to formation of photocatalytic coating films, and application of sol-gel method to bioactive coating films. The comprehensive scope and integrated treatment of topics make this reference volume ideal for R&D scientists and engineers across a wide range of disciplines and professional interests.