Current-less anodization of intrinsic silicon powder grains: Formation of fluorescent Si nanoparticles

Abstract

We examine current-less anodization of Si powder grains which are dispersed in a liquid. The grains are prepared red luminescent using a platinum catalyst from a chloroplatinic acid precursor. We also use the procedure to form dispersions of fluorescent Si nanoparticles in the size range of 3–6 nm across by subsequent sonication of the grains. The results are discussed in terms of the calculated thickness of the depletion layer in the grains due to a light metal doping and compared with recent results for the anodization of wirelike geometry.