ELFT HÍRADÓ

[Kugler Szilvia <kugler.szilvia AT wigner.mta.hu>]

Tisztelt Kollégák!


Szeretném felhívni figyelmüket Cyril Popov előadására, melyre 2017. 
április 7-én pénteken 10 órától kerül sor az RMI 3. épületének 2. 
emeleti Tanácstermében.

"Deposition, surface modifications, structuring and applications of 
nano- and ultrananocrystalline films"

Cyril Popov

/Institute of Nanostructure Technologies and Analytics (INA), Center for 
Interdisciplinary Nanostructure Science and Technology (CINSaT), 
University of Kassel, Germany/

popov AT ina.uni-kassel.de

Diamond possesses various unique properties such as extreme hardness, 
low friction coefficient, chemical inertness, high electrical 
resistance, excellent thermal conductivity and good biocompatibility. 
Upon doping it becomes a large band-gap semiconductor with an extremely 
high breakdown voltage and a high carrier mobility. It is transparent 
over a wide wavelength range and can withstand high electromagnetic 
radiation power fluxes from X-ray or laser sources. These outstanding 
properties make diamond of potential interest for a wide spectrum of 
applications including wear resistive and transparent protective 
coatings for optical components, heat spreaders, novel semiconductor 
devices, etc. However, the diamond coatings prepared by chemical vapor 
deposition (CVD) techniques are in most cases rough and non-uniform over 
large areas. The high surface roughness is a major problem for wear 
resistant applications of diamond films, for example in optical 
coatings, since it causes attenuation and scattering of the transmitted 
light. It also hinders the application of polycrystalline diamond films 
as coatings for bioimplants. A route to overcome the roughness problem 
is the decrease of the size of the diamond crystallites composing the 
films, depositing nano- (NCD) and ultrananocrystalline diamond (UNCD) 
films with grain sizes of several hundred nanometers or up to 10 nm, 
respectively. We have prepared both types of films by hot filament CVD 
and microwave plasma CVD and investigated their basic properties, namely 
morphology, topography, crystallinity, chemical bonding nature. Special 
attention was paid to the surface properties of NCD and UNCD films and 
the possibilities for their modifications by plasma or photochemical 
processes. We have demonstrated the surface modification of NCD films, 
followed by a functionalization with dye molecules (phthalocyanines) and 
a thorough characterization of the resulting surfaces by a variety of 
techniques. The initial photo-electrochemical experiments with such 
dye-sensitized NCD coatings revealed the generation of photocurrent, 
which makes them a novel platform for solar energy conversion. We have 
also investigated the bio-properties of UNCD films, like cytotoxicity, 
bioinertness, etc., their surface modifications and characterization, 
and the possibility for their application for long-term growth and 
investigation of neurons. Applying lithography and plasma etching both 
types of films can be nanostructured, as demonstrated for example with 
NCD nanopillars, which can be integrated with color centers.


Minden érdeklődőt szeretettel várunk!

A szervezők nevében üdvözlettel,

Kugler Szilvia

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