Study of the Optical and Structural Properties of Silicon–Carbon Nanometric Powder Using Infrared Phase Modulated Ellipsometry and Electron Microscopy

Abstract

Hydrogenated amorphous silicon–carbon (a‐SiC : H) nanometric powder was produced in an rf plasma of SiH4 and CH4. Particle size, composition and powder yield were controlled by plasma modulation, SiH4/CH4 flow ratio and pressure of the gas mixture inside the plasma reactor. Quasi‐monodisperse silicon–carbon nanopowder, with a size of about 30 nm, was studied by infrared phase modulated ellipsometry (IRPME), scanning (SEM) and transmission (TEM) electron microscopy. The optical properties of the discontinuous powder layer deposited onto non‐insulating substrates were fitted to a three‐layer system. The use of non‐metallic substrates allowed us to identify the contributions of different vibrational groups to the Si–H stretching band. The structural parameters determined by ellipsometry agree with the size, morphology and substrate coverage of the nanoparticles measured by SEM and TEM.

Influence of lanthanum on synthesis of SiC nanopowder

“…Although laser inducement, chemical vapour deposition and other methods can be used to prepare SiC nanoparticles, the equipment is expensive and the processes are low output, so SiC powder remains expensive. 16,17 For these reasons, it is necessary to find a new method for SiC nanoparticle preparation required low cost solution and can be used for industry production. Carbothermal reduction represents the most effective method for low cost and large scale production of b-SiC nanopowder, but the high synthesis temperature leads submicrometre particle size.…”