Investigation of Chlorinated Silicon Nanoparticles and In situ Analysis of the Size Distribution of Plasma Produced Particles

Abstract

Chlorine terminated silicon nanoparticles are produced from a non equilibrium plasma setup. The reactive chlorinated surface is exploited to functionalize the particles using Grignard chemistry and to stabilize the particles in solvent. By functionalizing the particles using Grignard chemistry, the particles form an optically clear solution in diethyl ether that is stable for four months. Chlorine surface coverage was successfully modulated by changing the precursor flowrate during synthesis. The solubility of as produced particles in methyl ethyl ketone was found to be related to the amount of precursor used during synthesis. A low pressure differential mobility analyzer (LPDMA) was installed downstream of a silicon nanocrystal plasma reactor in order to take in situ measurements of particle size distributions. Roughly equal amounts of positive and negative particles are observed. Size distributions of particles measured by the LPDMA are found to be much broader than those observed in TEM. This broadening is believed to be due to in flight coagulation. Inserting a mesh downstream of the plasma reduced the broadness of the distributions.