Silicon as an emissive optical medium

One of the great challenges in photonics has been to modify silicon to enhance light emission properties. In this review article we survey recent studies which have generated light from silicon in a variety of ways including introduction of emissive centers, anodization, fabrication of quantum-confined structures and by utilizing non-linear effects. Each method offers insight into silicon as an emissive medium, but no one method has proven effective enough a light source to compete with established technologies based on Ill-V and H-VI compound semiconductors, and in particular no one method of inducing light emission in silicon has made possible an electricatly-pumped silicon laser. Photoluminescence spectra from nanopatterned silicon superimposed on a scanning electron micrograph of the emissive structure.