Large current density and anodization time needed for strong photoluminescence in porous silicon

We investigated the relation between anodization conditions and photo lumin escent characteristics including spatial variations. The current density wa s between 7.9 and 39 mA cm(-2), and the anodization time between 10 and 60 min. We clarified a generous tendency as follows: as the current density or the anodization time increases, the edge of the anodized area gives the st ronger photoluminescence, at first, and then the center also gives the stro nger photoluminescence. In addition, we reported the difference between lum inescing and non-luminescing porous silicon, from the aspects of photolumin escent, photoacoustic, and Raman spectra. (C) 2001 Elsevier Science B.V. Al l rights reserved.