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The deposition of Ga and GaN nanostructures on silicon and graphene substrate
Novák, Jakub ; Jarý, Vítězslav (referee) ; Mach, Jindřich (advisor)
The thesis is focused on the study of properties of GaN nanocrystals and Ga structures on the surface of silicon and graphene substrate. In the theoretical part of this thesis, the basic properties of Ga/GaN and graphene are described, as well as their applications or connection of both structures together in different devices. The ability of metal nanoparticles to enhance not only photoluminescence, due to the interaction of the material with surface plasmons, is also shown in several examples. The experimental part of the work first deals with the production and characterization of graphene sheets prepared by Chemical Vapor Deposition. Ga/GaN growth on both types of substrates was performed in a UHV chamber using an effusion cell for Ga deposition and an atomic ion source for nitridation. Prepared structures were characterized using various methods (XPS, SEM, AFM, Raman spectroscopy or photoluminescence). In the last step, GaN nanocrystals were coated with Ga islands to study the photoluminescence enhancement.
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Aplication of SPM in study and modification of ultrathin films Pt, Co and graphene
Lišková, Zuzana ; Červenka,, Jiří (referee) ; Bartošík, Miroslav (advisor)
This diploma thesis deals with the preparation of the very thin films and their investigation by scanning probe microscopy methods. The ultrathin films of Pt on Pt(111) were created by pulsed laser deposition and the ultrathin films of Co on Pt(111) were deposited by thermal evaporation. The coverage of the substrate was much smaller than one monolayer (in order of hundredths of monolayer). The nucleation theory was verified by these experiments using so-called Onset method. Further graphene sheets were prepared on layer of Si/SiO2 by the mechanical exfoliation from the graphite crystal. The fabricated graphene sheets were studied by micro-Raman spectroscopy, microreflectometry, atomic force microscopy and similar techniques. These methods proved the thinnest graphite layers were consisted of two graphene monolayers.
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The deposition of Ga and GaN nanostructures on silicon and graphene substrate
Novák, Jakub ; Jarý, Vítězslav (referee) ; Mach, Jindřich (advisor)
The thesis is focused on the study of properties of GaN nanocrystals and Ga structures on the surface of silicon and graphene substrate. In the theoretical part of this thesis, the basic properties of Ga/GaN and graphene are described, as well as their applications or connection of both structures together in different devices. The ability of metal nanoparticles to enhance not only photoluminescence, due to the interaction of the material with surface plasmons, is also shown in several examples. The experimental part of the work first deals with the production and characterization of graphene sheets prepared by Chemical Vapor Deposition. Ga/GaN growth on both types of substrates was performed in a UHV chamber using an effusion cell for Ga deposition and an atomic ion source for nitridation. Prepared structures were characterized using various methods (XPS, SEM, AFM, Raman spectroscopy or photoluminescence). In the last step, GaN nanocrystals were coated with Ga islands to study the photoluminescence enhancement.
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Aplication of SPM in study and modification of ultrathin films Pt, Co and graphene
Lišková, Zuzana ; Červenka,, Jiří (referee) ; Bartošík, Miroslav (advisor)
This diploma thesis deals with the preparation of the very thin films and their investigation by scanning probe microscopy methods. The ultrathin films of Pt on Pt(111) were created by pulsed laser deposition and the ultrathin films of Co on Pt(111) were deposited by thermal evaporation. The coverage of the substrate was much smaller than one monolayer (in order of hundredths of monolayer). The nucleation theory was verified by these experiments using so-called Onset method. Further graphene sheets were prepared on layer of Si/SiO2 by the mechanical exfoliation from the graphite crystal. The fabricated graphene sheets were studied by micro-Raman spectroscopy, microreflectometry, atomic force microscopy and similar techniques. These methods proved the thinnest graphite layers were consisted of two graphene monolayers.
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