Mechanism of solid-liquid-solid on the silicon oxide nanowire growth

The solid-liquid-solid growth mechanism of synthesizing SiOx nanowires is expressed in detail through analyzing the structure and composition of the catalysts and the nanowires. The silicon source for growing nanowires was directly provided from the silicon wafer. A thin catalyst layer of platinum (∼5 nm) was first deposited on the silicon wafer by sputtering. The platinum film collapsed into dots with diameter about hundreds of nanometers during the thermal process. These dots transformed into crystalline platinum silicide (Pt₃Si) and served as nucleation seeds for the silicon oxide nanowire growth. Due to the high process temperature (∼1100 °C) and long duration time (∼5 h), the silicon wafer transformed into amorphous silicon oxides and melted into the Pt₃Si catalyst dots until supersaturated to form SiOx nanowires. Such nanowires are amorphous and have an average diameter of about 40–60 nm and length of several hundreds of micrometers.