The formation mechanism of Si nanocrystals in SiO2

Influences of annealing temperature on the optical properties of SiOx thin film prepared by reactive magnetron sputtering

“…Still, the results can tell us that the phase separation of SiO x into amorphous Si and SiO 2 becomes dominate, and that there is an increase in the concentration of the pure Si phase as the annealing temperature rises. The mechanism of the separation of SiO x into pure Si and SiO 2 at a temperature above 400 8C has been studied and confirmed by a number of experimental and theoretical work [28,29,31]. According to Ref.…”

“…[28], a similar behavior of the absorption edge was observed in the SiO x films annealed in Ar atmosphere. In another work, by observing the annealing time revolution in N 2 atmosphere of Si + ion implanted SiO 2 films, Wang et al [29] concluded three growth phases: formation of amorphous Si-rich SiO x nodules; transformation into crystalline Si nanoparticles and coalescence into larger ones. In the temperature region below 500 8C, the blue shift of E g with annealing temperature was attributed to the healing effect of some of the ordering parameters in the random-binding model [30], such as the dangling bond density and the site ordering of the atoms [26,28].…”

Silicon nanocrystal synthesis by implantation of natural Si isotopes

“…For greater annealing times, the PL-emission decreases and is shifted towards the red. The PL spectral shift (arrows) for annealing times longer than 23 min can be explained by the formation of larger Si-nc from the clustering of small Si-nc produced at the beginning of the thermal annealing [16]. In Fig.…”

Combining Rare Events Techniques: Phase Change in Si Nanoparticles

“…Results from Energy Filtered Transmission Electron Microscopy (EFTEM) and Dark-Field Transmission Electron Microscopy (DFTEM) on Si-rich SiO x show that Si nanoparticles start to form at 1000 • C [28,29,24,25,30,27]. At this temperature they are all amorphous, while at 1100 • C about one third become crystalline.…”