Temperature dependence of the quality of silicon nanowires produced over a titania-supported gold catalyst

Silicon nanowires (SiNW) have been prepared at different temperatures by chemical vapor deposition of silane over a titania-supported Au catalyst. It was found that the SiNW produced at 500 °C have a well-crystallized silicon core with a very thin amorphous silicon dioxide outer layer. At temperatures lower or higher than 500 °C, both yield and quality greatly decrease. Different controlling rate-limiting steps are proposed to explain the difference in quantity and quality of the products obtained as a function of temperature.