Speaker
Miroslav Snirer
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P1.3010.pdf
Plasma diagnostics during microwave plasma synthesis of graphene
nanosheets
M. Snirer, V. Kudrle, O. Jasek, J. Toman, J. Jurmanova
CEPLANT, Masaryk University, Brno, Czech Republic
Graphene nanosheets possess many extraordinary properties with promising applications, e.g.
in energy storage. However, suitable technique for cost effective synthesis is needed. Microwave
plasma is one of the considered techniques but requires further diagnostics of the influence of
different parameters to control the synthesis and to yield a high quality graphene [1].
Graphene nanosheets were synthesized by decom-
position of precursor (ethanol) vapours in argon mi-
crowave plasma excited by surface wave launcher
(surfaguide [2]) at 2.45 GHz. The synthesis process
took place in the volume, i.e. no substrate or cata-
lyst was needed and the product was in a flake form.
Their quality could be controlled by the flow of carrier
gas, the amount of precursor and the input microwave
power. We performed the synthesis in both low pres-
sure and atmospheric pressure regimes. Different ar-
gon flows were tested in the range 0.2-3 L/min with
various ethanol percentages. The main plasma parame-
ters were studied by optical emission spectroscopy and
Figure 1: Emission spectra of Ar plasma
microwave interferometry. Spatial evolution of the gas
with ethanol admixture (top) and SEM
temperature was calculated from the emission spec-
image of graphene flake. Experimental
tra, too. The synthesized graphene sheets were ana-
conditions: 350 W argon 280 sccm, pres-
lyzed by Raman spectroscopy and scanning electron
sure 500 Pa, partial pressure of ethanol
microscopy.
vapours 66 Pa.
This work was supported by the Czech Science
Foundation under project 18-08520S and in part by the project LO1411 (NPU I) funded by
Ministry of Education, Youth and Sports of Czech Republic.
References
[1] M. Aliofkhazraei, N. Ali, W.I. Milne, C.S. Ozkan, S. Mitura, J.L. Gervasconi, Graphene Science Book, 2016.
[2] M. Moisan, Z. Zakrzewski, Plasma sources based on the propagation of electromagnetic surface waves. J.
Phys. D: Appl. Phys. 24, 1025 (1991).
