AVS 53rd International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS2-WeA

Paper PS2-WeA7
Use of Dual Atmospheric Microdischarges for Manipulating the Growth of Silicon Nanoparticles

Wednesday, November 15, 2006, 4:00 pm, Room 2011

Session: Atmospheric and Microplasmas
Presenter: N.A. Brunelli, California Institute of Technology
Authors: N.A. Brunelli, California Institute of Technology
K.P. Gipias, California Institute of Technology
R.C. Flagan, California Institute of Technology
Correspondent: Click to Email
Atmospheric microdicharges have been shown@footnote 1@ to produce Silicon nanoparticles between 1-2 nm in diameter, which exhibit intense photoluminescence emission at 420 nm with a quantum efficiency of 30%. It is desirable to obtain emission at longer wavelengths for imaging applcations, by increasing the diameter of the nanoparticles. However, it has been exceedingly difficult to manipulate the nanoparticle size in a single microdischarge, where perturbations to the growth conditions seem to only influence the number of particles produced while the size remains invariant. We demonstrate here that by using two microdischarges in series that silicon nanoparticles generated in the first microdischarge can be overgrown to larger sizes in the second microdischarge. The addition of precursor in the second microdischarge and adjustment of other operating parameters allows the particle size to be tuned. We quantify this claim by using a new ultrafine radial differential mobility analyzer (UF-rDMA) immediately after the second microdischarge to monitor in real time the particle size. The particles are then deposited on solid substrates for independent size verification by atomic force microscopy (AFM). Finally, we characterize the nanoparticles by photoluminescence and transmission electron microscopy. @FootnoteText@ @footnote 1@ R.M. Sankaran, et al. Nano Lett. 5 (3) 2005.