Colloidal Synthesis of Silicon Nanocrystals Via Inverse Micelles Microemulsion

We describe here the synthesis and characterization of silicon nanocrystals prepared by using microemulsion technique which involved the formation of inverse micelles. Colloidal systems employing TOAB as the surfactant molecules were used to synthesise nanosized silicon nanocrystals. The initial reaction of silicon tetrachloride, SiCl₄ with a strong reducing agent, NaBH₄ produced Si nanocrystals with hydrogen terminated surfaces. The surfaces of the nanocrystals were then capped with 1-heptene which protected the silicon nanocrystals from oxidation. The resultant surface passivated silicon nanocrystals suspended in organic solvent were characterized by Fourier transform infrared spectroscopy, photoluminescence spectroscopy and high resolution transmission electron microscopy. This study provided direct evidence of ageing, stability of different surface passivation and the quantum confinement effect in nanosized silicon nanocrystals.