The importance of low dimensional silicon nanostructures are rapidly increasing in the fields of material research and technological applications. It is well known that silicon is a dominating material in microelectronics but not a suitable material for optoelectronics due to its indirect band-gap nature. So the main objective is to overcome these difficulties by getting light emission from silicon-compatible photonic materials. Development of such materials is essential for integrating electronic and photonic devices on a single silicon chip. The work embedded in this book provides useful information for fabricating various types of silicon nanoparticles and nanostructures. Underlying mechanisms governing the optical properties of these materials have been studied in detail. These studies may be extended to understand various aspects of these nanoparticles and nanostructures as discussed in various chapters. Such studies are essential for realizing practical devices envisaged in this book.