Low dimensional Silicon as a photonics material

In this chapter the state-of-the-art on the development of low dimensional silicon for application in photonics is presented with the aim to settle the status and try to weight out the perspectives. The necessity for Si-based photonics is introduced, and special emphasis is dedicated to the subject which is at the forefront of the today discus-sion: the route to a silicon light source. Two examples are detailed: silicon nanocrystals and Er doped silicon nanocrystals