Plasma reactor with pms

Aim
Gasphase synthesis of nanoparticles using high temperature gradients and short residence time can be realized in plasma reactors. They also allow for online and inline diagnostics. The characterization of the synthesized products within the high temperature gradient zone yields information about the involved growth processes and their kinetics. The start of particle formation process is analyzed with a particle mass spectrometer (PMS) that is connected to the reactor. The reactor also allows to produce sufficient amounts of material for further ex-situ characterization methods (TEM, BET, XRD). Furthermore, selected nanoparticles with a selected size can be deposited on unstructured and structured substrates for the characterization of specific material properties.

Approach
The microwave plasma reactor constitutes a microwave source (f = 2.45 GHz) with a maximum power of 2 kW and a 30 mm diameter fused silica tube as the reactor zone. The pressure in the reactor can be varied between 10 and 100 mbar. A large number of precursors are used such as silane, methane and TTIP. With the ability to perform online-analysis using the particle mass spectrometer, the particle size and particle size distribution can be measured in-situ. The reactor is enhanced by gas analytics (MS) and laser diagnostics (NO LIF, atom LIF). Deposition of nanoparticles with a selected size is realized by molecular beam sampling as multi or sub mono layers.

References
J. Knipping, H. Wiggers, B. Rellinghaus, P. Roth, D. Konjhodzic, C. Meier, Synthesis of High Purity Silicon Nanoparticles in a Low Pressure Microwave Reactor, J. Na-nosci. Nanotechnol. 4 (2004) 1039-1044

Contact
Dr. H. Wiggers, Hartmut Wiggers, Tel: +49 (0)203 - 379 8087, IVG