Deposition of gold and silver on porous silicon and inside the pores

Silver and gold were spontaneously deposited on porous silicon (PSi) by immersion-plating. Each metal formed crystallites of typical shapes on top of the PSi layer. Deposition of these metals inside the pores could be achieved by performing the immersion-plating in an ultrasonic bath. Top view and cross-section scanning electron microscope images show slight penetration of silver into the pores but massive filling of gold, to depth of several hundreds of nanometers.