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Preparing of Grätzel solar cell
Gerlich, Jakub ; Strachala, Dávid (referee) ; Kadlec, Michal (advisor)
This bachelor thesis focuses on the problematic of the dye-sensitized solar cells. The thesis states the working principle of these cells. It also deals with the use of different types of dyes, counterelectrodes, electrolytes and conducting glass. The thesis also contains the principles used in measuring the effectivity of solar cells. The manufacturing process of these cells is described in this thesis. The practical part of the thesis is focused on the manufacture of cell prototypes and the measuring of their parameters.
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MPPT driver for small UAV
Košút, Martin ; Záplata, Filip (referee) ; Kubíček, Michal (advisor)
This thesis describes a design of a maximum power peak tracking controller for a solar cell array embedded on a wing of a UAV. Solar cells are used to both cover part of the UAV power consumption and (at suitable conditions) to charge onboard battery. As the UAV changes its position and attitude to the sun relatively fast, the lighting conditions on the solar cells change rapidly. Thus, it is necessary to implement a fast maximum power peak tracking regulator to ensure maximum efficiency of the system. The proposed design is based on commercial offtheshelf components. The implemented DC/DC converter, which represents the core of the regulator, is a combination of a stepup and a stepdown converter. Weight, dimensions end overall efficiency were the key optimization parameters of the design.
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Dynamic testing of solar cells
Šneidr, Radim ; Hégr, Ondřej (referee) ; Boušek, Jaroslav (advisor)
The content of this thesis is the validation of the method of dynamic testing of solar photovoltaic cells. Testing methods for determining the parameters of the photovoltaic cell replacement scheme has been verified through testing a set of crystalline silicon photovoltaic cells. To accelerate the diffusion capacity measurement and to improve reproducibility of the measurement we propose new method of determining the time constant for diffusion capacitance using a combination of two short pulses. For this method of measurement new scheme for dynamic tester timing has been proposed and implemented.
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Organic semiconductors
Tebich, Ivan ; Macháček, Martin (referee) ; Boušek, Jaroslav (advisor)
My final thesis treats of usage photovoltaic phenomenon to production electric energy by solar cells. It inquires into this phenomenon in organic structures. Further it mentions basic types of constructions organic solar cells and evaluates their properties. In experimental part zhe thesis is focused on characterization thin-film structures made out of photoconductiv organic materials.
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Silicon solar cells: methods for experimental study and evaluation of material parameters in advanced structures
Holovský, Jakub ; Vaněček, Milan (advisor) ; Sládek, Petr (referee) ; Hlídek, Pavel (referee)
This work concerns with today's challenges of photoelectrical characterization methods in the research and development of thin film silicon solar cells. Relevant results are obtained only when photocurrent spectroscopy and measurement of current-voltage characteristics, are applied on the real structures that can however be multi-layered, multi-junction devices with nanostructured interfaces. Analytical and numerical optical models comprising light scattering are used for analysis of light absorption and for evaluation of optical absorption coefficient of silicon layers in sub-gap region. The slope of absorption edge and residual absorption in mid-gap indicate material disorder and defect density. Based on the investigation of electrical interaction between sub-cells in the dual-junction solar cell we developed new methods of evaluation of photocurrent spectra and current-voltage characteristics individually for each sub-cell with no need to contact them directly. Usability of Fourier Transform Photocurrent Spectroscopy as a robust method for photocurrent spectroscopy of amorphous silicon is thoroughly analyzed here. The issues of frequency dependence are addressed in detail and comparison with photothermal deflection spectroscopy is made.
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Mppt Controller For Uav
Košút, Martin
This paper describes a prototype design of a maximum power peak tracking controller for a solar cell array embedded on a wing of UAV. Solar cells are used to both cover part of the UAV power consumption and (at suitable conditions) to charge onboard battery. As the UAV changes its position and attitude to the sun relatively fast, the lighting conditions on the solar cells change rapidly. Thus, it is necessary to implement a fast maximum power peak tracking controller to ensure maximum efficiency of the system. The proposed design is based on commercial off-the-shelf components. The implemented DC/DC converter, which represents the core of the regulator, is a combination of a step‑ up and a step‑ down converter. Weight, dimensions end overall efficiency were the key optimization parameters of the design.
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Degradation of GaAs Solar Cells
Papež, Nikola ; Pinčík,, Emil (referee) ; Lazar, Josef (referee) ; Sobola, Dinara (advisor)
Solární články na bázi arsenidu gallia patří mezi nejvýkonější typ dostupných solárních článků vůbec. Jejich výhodou je výborná odolnost vůči tepelnému a ionizujícímu záření, a proto se využívají zejména v náročných podmínkách. Tato disertační práce popisuje stav GaAs fotovoltaických článku vystavených vůči tepelnému namáhání, vysokému ochlazování, gama záření a ozáření širokospektrálním laserem. Vzorky byly zkoumány před, po a i během těchto procesů pomocí několika analytických a charakterizačních metod. Měření bylo zaměřeno na charakterizaci povrchu, optických a elektrických vlastností. Byly objeveny limity a nové chování tohoto typu článků, které jsou ovlivněny i tenkými ochrannými a antireflexními vrstvami.
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MPPT driver for small UAV
Košút, Martin ; Záplata, Filip (referee) ; Kubíček, Michal (advisor)
This thesis describes a design of a maximum power peak tracking controller for a solar cell array embedded on a wing of a UAV. Solar cells are used to both cover part of the UAV power consumption and (at suitable conditions) to charge onboard battery. As the UAV changes its position and attitude to the sun relatively fast, the lighting conditions on the solar cells change rapidly. Thus, it is necessary to implement a fast maximum power peak tracking regulator to ensure maximum efficiency of the system. The proposed design is based on commercial offtheshelf components. The implemented DC/DC converter, which represents the core of the regulator, is a combination of a stepup and a stepdown converter. Weight, dimensions end overall efficiency were the key optimization parameters of the design.
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