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

Abstract

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 (∼5nm) 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 (∼5h), 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.

Controlled synthesis and characterization of single crystalline MnO nanowires and Mn–Si oxide heterostructures by vapor phase deposition

“…As is known, oxygen partial pressure is a function of temperature and increases with increasing temperature [31]. Depending on the evaporation and oxidation dynamics of the manganese in the system, a higher heating rate might give a quick increase of the oxygen partial pressure in the chamber, which possibly led to high oxidizing rate of the manganese powder and decreased the vapor pressure of manganese.…”

Amorphous SiOx nanowires catalyzed by metallic Ge for optoelectronic applications

“…Metallic catalysts, such as Pt [23], Au [24], Fe [11], Cu [25], Co [26] and Ni [21], have been used for growing SiO x nanowires. Generally, such metallic catalysts may incorporate into the nanowires during the nanowire growth [27].…”

Dewetting process of Au films on SiO2 nanowires: Activation energy evaluation

“…It was fabricated by a solid state methodology established in the last decade [11][12][13][14][15][16][17][18]. After deposition of 20 nm Au film on a cleaned CZ-〈111〉 Si, 1373 K-1 h annealing ( Fig.…”

“…However, recently, a simple and versatile solid state reaction based method was developed for the large area production of SiO 2 NWs on surfaces [11][12][13][14][15][16][17][18]; it is based on a solid-state reaction of thin metal films (such as Au, Ni, Pd, having an eutectic reaction with Si) deposited on a Si substrate and annealed at high temperatures. For example [18], after deposition of a thin (5-50 nm) Au film on a Si substrate, a high temperature annealing (41273 K) in N 2 or Ar environment with trace amounts (some ppm) of oxygen, determines the dewetting process of the Au film in nanoscale droplets reacting with the Si substrates and forming, so, molten droplets of Au-Si eutectic composition (in fact, the Au/Si phase diagram has an eutectic point at 636 K with a 18.6 at% of Au [12]).…”