Size and spectroscopy of silicon nanoparticles prepared via reduction of SiCl₄

Synthesis of silicon nanoparticles of various sizes from 3 to 9 nm in diameter was accomplished via a low temperature solution route. These nanoparticles are prepared via reduction of SiCl₄ with Na naphthalide in dimethoxyethane and capped with octasiloxane. The resulting nanoparticles were characterized by transmission electron microscopy (TEM), high resolution (HR) TEM, selected area electron diffraction (SAED), energy dispersive X-ray (EDX) spectroscopy, powder X-ray diffraction, UV-vis, photoluminescence, and their quantum yields were determined. TEM micrographs show that the nanoparticles are well dispersed and SAED and lattice fringes are consistent with diamond structured silicon. X-ray powder diffraction provides no diffraction peaks. UV-vis and photoluminescence show characteristic shifts corresponding to size, consistent with quantum confinement. The smallest sized nanoparticles show the largest quantum yield, consistent with an indirect bandgap nanoparticles.