Silicon has been, and continues to be, the material support of integrated circuit (IC) technology-the enabling tool of one of the most impressive technological, industrial and social revolution of mankind. Silicon (both in monocrystalline and polycrystalline form as well as epitaxial silicon, silicon on insulator and silicon on nothing) has grown with IC technology for its ability to match the numerous and complex needs of microelectronics. In recent years, however, IC technology is experiencing problems of maturity that are expected to be soluble only by huge investment in fabrication plants. This state of affairs has motivated the search for potentially cheaper alternatives to the basic IC element-the metal-oxide-semiconductor (MOS) field-effect transistor (FET). Solutions involving the use of low dimensional structures (like silicon nanowires for the crossbar structure, or silicon quantum dots for single-electron transistors) instead of conventional MOS-FETs have been proposed. Remarkably enough, such a nano-engineered silicon has been proved to be of interest not only in electronics but also in photonics, energetics, and biomedicine.