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Semiconductor nanowire growth modelling
Kovács, Roland ; Bartošík, Miroslav (referee) ; Kolíbal, Miroslav (advisor)
This bachelor’s thesis deals with modelling of semiconductor nanowires growth. The work describes the mechanism of growth using the VLS method. The main objective is to simulate the distribution of eutectic material in a droplet in the initial stage of growth. Mathematical models describing different situations of material diffusion in the droplet were depeloped. The simulation model is programmed in MATLAB.
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Controlling of Nanostructure Temperature by Light Absorption
Kovács, Roland ; Schmidt,, Eduard (referee) ; Kalousek, Radek (advisor)
The thesis deals with a new versatile strategy which is aimed to heat up rapidly the nanostructures with the help of a focused light beam utilizing localized plasmons (collective oscillation of electrons). By local heating, the growth of the semiconductor nanowires can be initiated and controlled at any arbitrarily prespecified location down to the single nanostructure level in a chamber at room-temperature. The aim of the work is to study electromagnetic field in the selected structures, especially in metal nanospheres by using numeric calculations and computations of the thermal field in the vicinity of these illuminated nanostructures. Electromagnetic phenomena is simulated in Lumerical and the temperature field in COMSOL.
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Preparation of low-dimensional III-V semiconductors
Stanislav, Silvestr ; Detz, Hermann (referee) ; Kolíbal, Miroslav (advisor)
Tato diplomová práce se zabývá přípravou nanostruktur z indium arsenidu (InAs) pomocí metody molekulární svazkové epitaxe (MBE). Důraz je kladen na výrobu struktur ve formě nanodrátů na křemíkovém substrátu. V úvodní části práce je popsána motivace pro studium III-V polovodičů a konkrétně InAs. Následující kapitoly vysvětlují dva základní princpy tvorby nanodrátů. Experimentální část práce diskutuje možnost přípravy indiového katalyzátoru pro samokatalyzovaný růst InAs nanodrátů v konkrétní aparatuře MBE. Následuje prezentace výsledků růstu InAs nanodrátů mechanismem selektivní epitaxe (SAE). Nanodráty byly vyrobeny na substrátu s termálně dekomponovaným oxidem a rovněž na substrátech s litograficky připravenou oxidovou maskou.
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Growth of highly doped ZnO nanowires
Andrýsek, Michal ; Macák, Jan (referee) ; Kolíbal, Miroslav (advisor)
This diploma thesis is about ZnO nanowires growth, their doping and analysis. High temperature and pressure oxidation of brass foil and deposition from effusion cell in oxidative atmosphere utilized for nanowires growth. The growth is affected by different temperature and pressure. It has been shown that under certain experimental conditions nanowires can be prepared by the former method. However, the growth was hindered when effusion cell was used.
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Electron beam modification of nanostructure growth
Kilian, Jakub ; Voborný, Stanislav (referee) ; Bábor, Petr (advisor)
This bachelor's thesis focuses on the further development of a method for modifying the surface of germanium using alloy Au-Ge droplets. A focused electron beam, which is brought in close proximity to the droplet, is utilized for thermomigration-induced motion of the droplets. The thesis is divided into two parts. The first part is dedicated to explaining the fundamental principles that are essential for a proper understanding of the conducted experiments. The theoretical overview also includes an introduction to the individual instruments utilized in the experimental section. In the practical part, the movement of Au-Ge droplets and the resulting surface morphology left by the droplets' passage were initially examined. The remaining portion of the practical research concentrated on utilizing the focused electron beam for controlled growth of nanowires in the VLS process.
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Preparation of low-dimensional III-V semiconductors
Stanislav, Silvestr ; Detz, Hermann (referee) ; Kolíbal, Miroslav (advisor)
Tato diplomová práce se zabývá přípravou nanostruktur z indium arsenidu (InAs) pomocí metody molekulární svazkové epitaxe (MBE). Důraz je kladen na výrobu struktur ve formě nanodrátů na křemíkovém substrátu. V úvodní části práce je popsána motivace pro studium III-V polovodičů a konkrétně InAs. Následující kapitoly vysvětlují dva základní princpy tvorby nanodrátů. Experimentální část práce diskutuje možnost přípravy indiového katalyzátoru pro samokatalyzovaný růst InAs nanodrátů v konkrétní aparatuře MBE. Následuje prezentace výsledků růstu InAs nanodrátů mechanismem selektivní epitaxe (SAE). Nanodráty byly vyrobeny na substrátu s termálně dekomponovaným oxidem a rovněž na substrátech s litograficky připravenou oxidovou maskou.
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Growth of highly doped ZnO nanowires
Andrýsek, Michal ; Macák, Jan (referee) ; Kolíbal, Miroslav (advisor)
This diploma thesis is about ZnO nanowires growth, their doping and analysis. High temperature and pressure oxidation of brass foil and deposition from effusion cell in oxidative atmosphere utilized for nanowires growth. The growth is affected by different temperature and pressure. It has been shown that under certain experimental conditions nanowires can be prepared by the former method. However, the growth was hindered when effusion cell was used.
|
|
|
Controlling of Nanostructure Temperature by Light Absorption
Kovács, Roland ; Schmidt,, Eduard (referee) ; Kalousek, Radek (advisor)
The thesis deals with a new versatile strategy which is aimed to heat up rapidly the nanostructures with the help of a focused light beam utilizing localized plasmons (collective oscillation of electrons). By local heating, the growth of the semiconductor nanowires can be initiated and controlled at any arbitrarily prespecified location down to the single nanostructure level in a chamber at room-temperature. The aim of the work is to study electromagnetic field in the selected structures, especially in metal nanospheres by using numeric calculations and computations of the thermal field in the vicinity of these illuminated nanostructures. Electromagnetic phenomena is simulated in Lumerical and the temperature field in COMSOL.
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Semiconductor nanowire growth modelling
Kovács, Roland ; Bartošík, Miroslav (referee) ; Kolíbal, Miroslav (advisor)
This bachelor’s thesis deals with modelling of semiconductor nanowires growth. The work describes the mechanism of growth using the VLS method. The main objective is to simulate the distribution of eutectic material in a droplet in the initial stage of growth. Mathematical models describing different situations of material diffusion in the droplet were depeloped. The simulation model is programmed in MATLAB.
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