Optical Properties of Silicon Nanostructures

Strong visible luminescence of porous silicon has triggered renewed general interest in the optical properties of silicon nanostructures. In addition to porous Si itself, Si‐based molecules, nanometer‐size Si particles, one‐dimensional Si chains, two‐dimensional Si layers, and many Si alloys are known to exhibit optical properties (absorption and luminescence) which strongly deviate from those of bulk crystalline Si. Here, we review and compare the main properties of the above‐mentioned systems and present a brief discussion of the experimental observations in terms of existing theories. Current prospects for Si‐based optoelectronic applications are also discussed.