The interior interfaces of a semiconductor/metal nanocomposite and their influence on its physical properties

A semiconductor/metal hybrid system with silicon as base material and embedded metal nanostructures is fabricated in two steps by anodizing the silicon substrate in an aqueous hydrofluoric acid solution and a subsequent electrodeposition process. The achieved self‐assembled nanoscopic hybrid system consists of a quasi‐regular 3‐dimensional arrangement of metal nanostructures embedded within the pores of the silicon matrix. The used metals are Ni, Co and their alloys, whereas mainly Ni is considered in the following. In such a hybrid system the interface between metal and silicon nanostructures is of interest in correlation with the properties of the material and can be influenced by different fabrication conditions. If the matrices are aged in ambient air before filling with a metal the inner surface of the porous silicon template offers a native SiOx layer due to the oxidation of the hydrogen terminated surface of the pore‐walls. Using as‐etched samples for deposition of the metal into the pores leads to the formation of a more complex interface during the cathodic deposition procedure which is observed by FTIR‐spectroscopy. Knowledge about the composition and the formation of the interior surface of the porous silicon matrix as well as the interface between semiconductor and metal is necessary on the one hand for interpretation of the gained experimental results and on the other hand to figure out possible applications of the fabricated hybrid system. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)