Flower-shaped gold crystals grown on anodic etched porous silicon

This paper reports the synthesis and characterization of flower-shaped gold (Au) crystals. The Au particles are synthesized via a facile route by dipping the freshly anodic etched porous silicon (Si) into HAuCl4·3H2O aqueous solution. The shape and size of Au clusters can be controlled by adjusting the concentration of HAuCl4 and duration of the reaction. The Au nanoparticles are in-situ formed and this process/reaction is accompanied by the oxidation of porous Si. This Au-coated porous Si electrode is confirmed to be a metal–insulator–semiconductor device by the current–voltage and the capacitance–voltage plots. Our work provides a very simple and convenient route to synthesize Au crystals on anodic etched porous Si.

► Au-coated porous silicon has been fabricated by a simple immersion plating method.
► As-prepared Au crystals have a novel flower-like shape.
► A metal–insulator–semiconductor (MIS) structure has been in-situ fabricated.