Crystalline Si nanoparticles below crystallization threshold: Effects of collisional heating in non-thermal atmospheric-pressure microplasmas

• Published in: Applied physics letters Vol. 104; no. 16
• Main Authors: Askari, S., Levchenko, I., Ostrikov, K., Maguire, P., Mariotti, D.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 21-04-2014
• Subjects: Applied physics; Atmospheric models; Crystal structure; Crystallinity; Crystallization; Heat flux; Heating; Ion density (concentration); Microplasmas; Nanoparticles; Nucleation; Silicon
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4872254

Nucleation and growth of highly crystalline silicon nanoparticles in atmospheric-pressure low-temperature microplasmas at gas temperatures well below the Si crystallization threshold and within a short (100 μs) period of time are demonstrated and explained. The modeling reveals that collision-enhanced ion fluxes can effectively increase the heat flux on the nanoparticle surface and this heating is controlled by the ion density. It is shown that nanoparticles can be heated to temperatures above the crystallization threshold. These combined experimental and theoretical results confirm the effective heating and structure control of Si nanoparticles at atmospheric pressure and low gas temperatures.