Morphology of porous silicon layers: image of active sites from reductive deposition of copper onto the surface

We report a scanning electron microscopy (SEM) investigation of the morphology of porous silicon layers and comparisons between our observations and a recent theory for its formation and morphology. Also examined was the use of porous silicon as a reducing agent in the preparation of Cu dispersed on the surface of the porous silicon. The morphology of the resulting copper deposits on the surface of the porous silicon layers in rum was used to infer the morphology of the hydrogenated, chemically active sites of the porous silicon. Conditions necessary for the reduction to take place, and the effect of the deposition upon the optical luminescence of the porous silicon are noted. (C) 1998 Elsevier Science B.V.