Greifswald 2024 – scientific programme
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P: Fachverband Plasmaphysik
P 14: Low Pressure Plasmas and their Application I
P 14.5: Talk
Wednesday, February 28, 2024, 12:15–12:30, WW 1: HS
Deposition system for graphene nanostructures — •Simeon Marinov, Ivan Ivanov, and Zhivko Kissovski — Faculty of Physics, Sofia University, St. Kl. Ohridski, Sofia, Bulgaria
A microwave plasma system has been developed for the deposition of carbon nanostructures on metal and ceramic substrates at low and atmospheric pressure. The microwave surface wave discharge at frequency of 2.45 GHz is applied for PECVD (Plasma Enhanced Chemical Vapor Deposition), because it produces a dense plasma providing efficient decomposition of the carbon precursor (methane CH4 or ethanol C2H5OH). At atmospheric pressure a plasma jet is used while at low pressure (0.4-8 Torr) a planar microwave plasma source as both discharges create a large number of reactive particles which results in lower substrate temperature for graphene deposition compared to CVD method. Optimization of the gas mixture of H2, Ar and the precursor, and the gas pressure in the chamber for the second setup results in a homogeneous graphene structures deposition on the substrates of Ni-foil, Ni-foam and ceramic substrates (SiC) at substrate temperatures in the range 600-750 ∘C. The plasma parameters such as gas temperature, electron temperature and density are obtained by measuring OH and CN-bands, Hβ broadening and Ar-lines using optical emission spectroscopy. The morphology of the carbon structures is obtained using SEM analysis and the characteristics of the graphene layers are determined by Raman spectroscopy. A self-consistent model of the atmospheric plasma jet is developed in COMSOL Multiphysics and plasma parameters in argon gas are obtained.
Keywords: plasma; graphene; deposition; nanostructures; PECVD