OPTICAL-PROPERTIES OF POROUS SILICON

The optical properties of porous Si films produced by electrochemical dissolution of Si are reviewed. From measurements of the optical absorption spectra an inverse relationship between the optical gap energy and the average nanoparticle size has been obtained demonstrating the quantum confinement of electron-hole pairs in Si nanocrystallites. There is also good agreement with theoretical predictions for Si quantum dots. A number of different sources of photoluminescence in anodized Si have been tentatively identified, and at least the red emission appears to be principally due to confinement in Si nanocrystallites.