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The oxygen modification of the graphene structures for biosensors
Mikerásek, Vojtěch ; Bartošík, Miroslav (referee) ; Mach, Jindřich (advisor)
The bachelor thesis deals with the modification of CVD graphene by oxygen atoms. The theoretical part describe the structure of graphene oxide and its physical properties. Methods of production of this material and its use in biosensors are also described. The practical part describes the preparation of monolayer graphene on a silicon wafer. The main attention was paid to the oxidation of graphene by atomic oxygen and its modification in oxygen plasma. The samples were measured during process of oxidation at individual time intervals using XPS.
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Design of an effusion cell for the deposition of Sn and Zn ultrathin layers
Horák, Stanislav ; Kolíbal, Miroslav (referee) ; Mach, Jindřich (advisor)
This bachelor thesis deals with the design and the construction of effusion cells for the deposition of zinc and tin ultrathin layers. In the introductory part there is an explanation of principles of eusion cells' functions, like a molecular beam epitaxy (MBE) or a construction of the efussion ow. Furthermore, the work describes a general principles of a ccreation of the atom sources. Theoretical part ends with review about the growth of ultrathin layers and nanostructures of zinc, tin and their compounds. Experimental part provides a design of the effusion cells with radiation heating from silicon carbide and heating by electrons impact. The complete drawing documentation of the designed effusion cells is included in the attachment.
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The photoluminescence properties measurement of ultrathin films
Metelka, Ondřej ; Mach, Jindřich (referee) ; Šamořil, Tomáš (advisor)
The thesis briefly describes the principles and types of luminescence. In the first following research of study is also discussed the equipment which is applicable to photoluminescence experiments, including the arrangement. The second research focuses on the influence of the properties of gallium nitride (GaN) (ultra) thin films and other structures prepared by various ways on shape of photoluminescence spectra. The paperwork also describes the further optimization of photoluminescent apparatus used for the measurement of photoluminescence spectrum in the UV light radiation which is located at the Institute of Physical Engineering at the Technical University. The extension of measurements at low temperatures (design and construction of its own cryostat) is added. The conclusion concernes the test measurements to determine the effect of various settings of the apparatus on the resulting measured photoluminescence spectrum.
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Study of interface graphene-on-silicon by EBIC method
Hammerová, Veronika ; Lišková, Zuzana (referee) ; Mach, Jindřich (advisor)
This bachelor thesis is dedicated to study of interface graphene-on-silicon located on solar cell with graphene layer. The interface was studied by EBIC method and Raman spectroscopy. Solar cells with graphene sheet was fabricated using electron litography, chemical etching and graphene made by CVD method. The thesis describes fabrication of solar cells with graphene layer, method EBIC measured on SEM and analysis of changes graphene-on-silicon interface caused by enlightenment electron beam by Raman spectroscopy. In theorethical part is described p-n junction and Schottky junction of solar cell, graphene and its fabrication, as well as EBIC method fundamentals.
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Development of the Atom and Ion Beam Sources
Tihlařík, Jan ; Voborný, Stanislav (referee) ; Mach, Jindřich (advisor)
This text is oriented for problems of creating ion beams. Thesis also describe the impact of ion optics to ion beam profile and preparing GaN layers. Also ion-atom source optimization and analysis of beam properties are there described. Also it was made deposition of GaN ultrathin layers on Si(111)dH at room temperature for different settings of atom-ion source electric electrodes.
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Design of the atomic source producing carbon beams for deposition of graphene in UHV conditions
Horáček, Matěj ; Kolíbal, Miroslav (referee) ; Mach, Jindřich (advisor)
This bachelor's thesis deals with the design of the atomic source of carbon beams for deposition of graphene in UHV conditions. In the first part, problems on the growth of ultrathin layers, the theory of atomic beams and molecular beam epitaxy are described. The second part is aimed to graphene layers - especially the growth of graphene using molecular beam epitaxy. In the third part, the detection of carbon atomic beams is discussed. The practical part of this bachelor's thesis deals with the design and the construction of high-temperature atomic source of carbon. In the conclusion the obtained results are discussed.
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Optimization of devices for deposition GaN nanostructures
Šimek, Daniel ; Voborný, Stanislav (referee) ; Mach, Jindřich (advisor)
This bachelor thesis deals with the automation of sources for the deposition of GaN nanocrystals used at the Institute of Physical Engineering. For the purpose of the thesis, the mechanism of automatic control of the gallium effusion cell shutter was designed and constructed and the control electronics containing components enabling automatic switching of the ion atomic source of nitrogen ions. In addition, samples of GaN nanocrystals on four different substrates that were studied for cold electron emission were prepared by the method of ion beam assisted molecular beam epitaxy IBA-MBE. The results of the measurement are discussed in the conclusion.
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Development and Application of an UHV Equipment for Deposition of Thin Films (Atomic and Ion Systems)
Mach, Jindřich ; Čech, Vladimír (referee) ; Lencová, Bohumila (referee) ; Šikola, Tomáš (advisor)
In the thesis the development of two equipment for preparation of ultrathin films under ultrahign vacuum conditions (UHV) is discussed. Here, additionally to a brief description of theoretical principles, more details on the design of these units are given. In the first part the design of a thermal source of oxygen or hydrogen atomic beams is discussed. Further, a design and construction of an ion–atomic beam source for ion-beam assisted deposition of thin films is detailed. The source combines the principles of an efusion cell and electron-impact ion beam source generating ions of (30 – 100) eV energy. The source has been successfully applied for the growth of GaN on the Si(111) 7x7 substrate under room temperature.
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The graphene structures suitable for field effect transistors
Kurfürstová, Markéta ; Bartošík, Miroslav (referee) ; Mach, Jindřich (advisor)
This bachelor’s thesis is focused on preparation of graphene structures suitable for field effect transistors. In the first section, graphene is characterized in terms of its properties and prepataion methods. The second part sums up semiconductor technology, focusing on transistors with graphene layer. Next, electron beam litography method is presented, which had been used for preparation of the structures. Finally, an experimental procedure of graphene structures manufacture is described.
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