Scientists at the Walter Schottky Institute of the Technical University of Munich, Germany, and Ecole Polytechnique in France have found the way of synthesizing silicon nanowires by using gallium as a catalyst. Avoiding gold as a catalyst in the VLS process is believed to result in nanowires with superior electronic and optoelectronic properties.

The difficulty of using other metals than gold has always resided in the fast oxidation of metals, when oxygen is present even in small concentrations. Now researchers have come up with a novel way to avoid this. The synthesis of the nanowires is realized in a reducing environment, by producing a hydrogen radical rich plasma. The growth of nanowires with the use of plasma enhanced chemical vapor deposition (PECVD) has an additional advantage. The decomposition of the silicon precursor (SiH4) is started in the gas phase, facilitating the complete catalytic decomposition at the gallium surface.

The team presented its work in Nanotechnology.