Synthesis of silicon nanocrystals

Abstract

We have prepared nanometer-sized silicon colloids in the range from 2 nm to 10 nm by a solution route. Silicon nanoparticles were prepared from Zintl salt, sodium silicide (NaSi) in ethylene glycol dimethyl ether (glyme). This synthesis provided a narrow range of particle size distribution under low-pressure and low-temperature conditions. The surface of silicon was passivated with the hydroxyl group (-OH) by the reaction of silicon nanoparticles with water. The average cluster size depended on the reflux time of NaSi in glyme. We report the photoluminescence of silicon nanocrystals, which provided strong evidence of quantum confinements. Additionally, particle size analysis and high-resolution transmission electron microscopy (HRTEM) confirmed the size distribution and material identity of the silicon nanocrystals.