AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Crystallizing Amorphous Silicon Nanoparticles with a Double Plasma Configuration
NICOLAAS J. KRAMER, Rebecca J. Anthony, Aloysius A. Gunawan, K. Andre Mkhoyan, Uwe R. Kortshagen, University of Minnesota
Abstract Number: 525 Working Group: Synthesis of Functional Materials using Flames, Plasmas and other Aerosol Methods
Abstract The crystallization conditions for Silicon nanoparticles formed in a non-thermal plasma have been studied with a double plasma configuration. Amorphous Silicon nanoparticles with sizes from 4 up to 7 nm were formed [1,2] in a low power primary plasma and flown into a separate secondary plasma, which was operated with variable powers. Once a specific threshold power was reached in the secondary plasma, the silicon nanoparticles became fully crystalline, as was demonstrated with X-ray Diffraction (XRD), Raman spectroscopy and Transmission Electron Microscopy (TEM) measurements. Depending on the conditions in the primary plasma, the nanoparticle size remained either constant or increased in size when the power of the secondary plasma was increased.
To study the plasma properties under crystallizing conditions, Capacitance probe and Optical Emission Spectroscopy measurements were performed in the region where the crystallization occurs. From this the properties of the secondary plasma, such as electron temperature and ion density, were obtained for several conditions.
N.J. Kramer acknowledges support by DOE grant DE/SC-0002391. R.J. Anthony and U.R. Kortshagen were supported in part by the DOE Low Temperature Plasma Science Center for Predictive Control of Plasma Kinetics. A.A. Gunawan and K.A. Mkhoyan acknowledge the NSF MRSEC DMR-0819885.
[1] L. Mangolini, E. Thimsen, U.R. Kortshagen, 2005, Nanoletters, 5, 655
[2] Z.C. Holman, U.R. Kortshagen, 2010, Nanotechnology, 21, 335302