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Perspectives in diamond thin film technology
Kromka, Alexander
Synthetic diamond thin films are routinely grown over world not only for basic research but also for industrial uses. At the Institute of Physics (IoP), diamond thin films are grown since 2002. The first installed deposition system is base on microwave plasma enhanced chemical vapor deposition (CVD) in hydrogen reach gas mixture (<2% methane diluted in hydrogen). This system is well suitable for fast growth of high quality diamond films up to 5 cm in diameter. The main advance of the system is cavity like resonator which allows running stable CVD process for several days at relatively high pressures (>200 mbar).
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Photonic structures and their preparation
Varga, Marián ; Ondič, Lukáš ; Hruška, Karel ; Potměšil, Jiří ; Libertínová, Jitka ; Kromka, Alexander ; Remeš, Zdeněk
Photonic crystals are periodically structured electromagnetic media, generally possessing photonic band gaps: ranges of frequency in which light cannot propagate through the structure. This periodicity, which length scale is proportional to the wavelength of light in the band gap, is the electromagnetic analogue of a crystalline atomic lattice, where the latter acts on the electron wavefunction to produce the familiar band gaps of semiconductors, and so on, in solid-state physics. Several examples of organisms and structures possessing photonic crystals and iridescence are visible all around us (Morpho didius, Pavo cristatus, Chrysochroa vittata, Chrysina resplendens, …).
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Study of nucleation and growth of diamond thin films
Ižák, Tibor ; Babchenko, Oleg ; Varga, Marián ; Potocký, Štěpán ; Marton, M. ; Vojs, M. ; Domonkos, Mária ; Kromka, Alexander
This study deals with the nucleation and growth of CVD diamond films on Si substrates. In nucleation part two different nucleation methods were studied: (i) the bias enhanced nucleation (BEN) and (ii) ultrasonic seeding. In the case of BEN, (i) the nucleation time and (ii) the influence of bias voltage were studied. For ultrasonic seeding the effect of different solutions of ultradisperzed detonation nanodiamond (UDD) powder with metal particles on the nucleation efficiency and growth process was investigated (i.e. diamond powder, nanosized Ni, microsized Co and Y metal powders).
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