Fabrication of ultra-small SiC nanoparticles with adjustable size, stoichiometry and photoluminescence by AC multi-arc plasmas

Ultra-small SiC nanoparticles with sizes smaller than 10 nm have wide prospects in optoelectronics and biomedical engineering, but challenges in their synthetic methods still limit their practical applications. In this paper, an AC multi-arc plasma device was designed for the continuous gas-phase synthesis of ultra-small SiC nanoparticles. SiC nanoparticles with an average size range of 7-10 nm, abundant surface functional groups, and obvious photoluminescence emission were fabricated by the decomposition of triethylsilane in AC multi-arc plasmas. The synthesized SiC nanoparticles had a typical core-shell structure, whose core was mainly beta-SiC and whose shell was covered by a few carbon layers. It was also found that the buffer gas effectively adjusted the particle size, crystal texture, stoichiometric ratio of each element, functional group composition, and photoluminescence. These adjustments were meaningful for the controllable preparation and practical utilization of ultra-small SiC nanoparticles. According to the product characteristics, the formation path of SiC nanoparticles and the influence of buffer gases were proposed.