|
|
Recycling of PV panels
Cingel, Štefan ; Vaněk, Jiří (referee) ; Jandová, Kristýna (advisor)
This bachelor thesis focuses in its first part on the distribution of PV cells, their development and production processes. There are also generally described recycling methods and their basic division and the species that are commonly used. Finally, the thesis also mentions the current state of PV panels in the Czech Republic and the related legislative regulation. The second (experimental) part is devoted to the selection of suitable PV modules for recycling. On these panels was performed measuring of the V-A characteristics and electroluminescence analysis. In cooperation with Aquatest was carried out recycling of selected panels, and then on the crushed material was carried out spectral analysis. The last part is an evaluation of recycling from economic and practical aspects.
|
|
|
SiO2 etching by Si deposition
Pokorný, David ; Bábor, Petr (referee) ; Polčák, Josef (advisor)
This bachelor thesis deals with one of the most interesting reactions taking place in the solid phase in UHV conditions and that is decomposition of SiO2 according to the equation Si + SiO2 = 2SiO. It was used the previously untested procedure - providing Si atoms not from substrate, but by direct deposition on the surface of the oxide. As a source of silicon atoms was used effusion cell. Deposition of silicon on SiO2 substrate was used at room temperature and at elevated temperature to clarify the principle of this reaction. The activation energy and temperature dependence of the reaction rate was determined. It was also verified the possibility of etching SiO2 by Si deposition in UHV conditions. The prepared samples were examined by x-ray photoelectron spectroscopy and atomic force microscopy.
|
|
|
Preparation of Ag/Co/Ag Trilayers
Burda, Pavel ; Kolíbal, Miroslav (referee) ; Čechal, Jan (advisor)
The Bachelor's thesis is aimed to the preparation of silver and cobalt ultrathin films. The films are formed on modified surfaces of crystalline silicon substrates (SiO2/Si(111), Si(111) ?H, Si(111) 7×7) and amorphous SiO2 in a form of a quartz glass. Thin films are grown using an effusion cell for Molecular Beam Epitaxy (MBE). Surface modified surfaces are covered subsequently by a silver, cobalt and silver thin layer. The individual film thickness is 6 nm. Consequently the samples are studied by the X-ray Photoelectron Spectroscopy (XPS) and the Atomic Force Microscopy (AFM). The morphology of thin films and growth modes are compared among the substrates. Growth modes change with the surface modification type. Complete trilayer system Ag/Co/Ag was prepared on SiO2/Si(111) and Si(111) 7×7. Such system can be employed in plasmonics in order to allow the control of surface plasmon polariton properties by an external magnetic field.
|
|
|
Experimental manufacturing of multiphase Ni-Si based layers
Rončák, Ján ; Moravčík, Igor (referee) ; Jan, Vít (advisor)
The diploma thesis deals with the preparation of the composite material based on the NiSi system using powder metallurgy supplemented by the sintering with the usage of SPS method (spark plasma sintering). Theoretical part contains general information about the mechanical-chemical process and sintering, while materials and methods used for experimental observation are explained in a separate chapter. Experimental part explains the procedure of the experiment and selected parameters of individual processes. In the experiment, two powder mixtures were created in order to form the NiSi phase in the maximum possible amount of powder material. After successfully reaching presence of the NiSi phase in the range of 87 to 89 wt. %, both mixtures were used to produce sintered samples at temperatures from 700 to 900 °C. Experiments showed the best results for sample number 2, which was sintered at 900 °C for 4 minutes. Resulting porosity was 0.9 % and hardness reached a maximum value of 718 HV 1. However, all sintered samples show cracks at room temperature associated with increased brittleness of the material.
|
|
|
Electroless selective deposition of silver nanoparticles
Salajková, Zita ; Bartoš, Miroslav (referee) ; Kolíbal, Miroslav (advisor)
Silver nanoparticles have a widespread use in the field of plasmonics. Since deposition of nanoparticles from colloidal solutions onto an exact location on a substrate is difficult, it seems advantageous to grow the nanoparticles in-situ. The presented work is focussed at selective deposition of~silver nanoparticles from colloidal solution or from solution reach of silver ions under assistance of focussed electron beams. Successful deposition could lead to growth of well defined nanostructures directly at the substrate surface. The effect of electron beam intensity to surface quality is studied (silica reduction, surface morphology) as well as effect of pH to particle properties. Outputs are used as a part in theoretical description of selective deposition and confirmed by following advanced experiments. The light assisted deposition and growth of nanostructures is described at the end of the presented work.
|
|
|
The power of solar radiation falling on a photovoltaic module
Kaliyev, Alexey ; Jandová, Kristýna (referee) ; Křivík, Petr (advisor)
The work is focused on the problem of the solar radiation power impacting on a photovoltaic module. In the theoretical part, the possibilities of using solar energy in renewable energy sources, especially in photovoltaic panels and solar collectors, were discussed and presented. Then the materials on the use of solar energy in these sources were reviewed. In addition, the three main components of incident solar radiation on a photovoltaic module or solar collector were described. Finally, the method for calculating the position of the sun across the sky was discussed and presented, as well as the method for calculating the various components of incident solar radiation on a photovoltaic module.
|
|
|
Photovoltaic power plants and their design
Albrecht, Daniel ; Walek, Agata (referee) ; Neuwirthová, Ludmila (advisor)
Tato bakalářská práce se zabývá fotovoltaickými elektrárnami a jejich návrhem. Významná část práce se věnuje především technologiím výroby a popisem typů a způsobu výroby jednotlivých druhů fotovoltaických článků. Práce se dále věnuje základním částem fotovoltaické elektrárny, jako jsou solární panely, baterie, regulátory, měniče, optimizery a transformátory. Součástí je také praktická část, pod níž patří kapitoly zabývající se podmínkami pro vhodné umístění elektrárny, dále faktory ovlivňujícími její budoucí energetický výnos a posléze už praktickým popisem jednotlivých komponent a součástí výstavby. Praktická část je ukončena porovnáním dvou již existujících elektráren, jenž jsou majetkem Geen Holding a.s., a kde autor práce popisuje, porovnává a hodnotí technické řešení projektů.
|
|
|
Fabrication of micro- and nanostructures by different etching methods
Těšík, Jan ; Urbánek, Michal (referee) ; Šamořil, Tomáš (advisor)
The selective etching is currently very widely used method for the preparation of micro- and nanostructures. This thesis deals with the principles of the etching methods, their applications and also the possibilities of dry and wet etching at the Institute of Physical Engineering. The experimental part is devoted to the preparation of the etching masks to ensure etching selectivity and to the preparation of pre-defined micro- and nanostructures. Important parameters were determined from the results, e.g. Si etch rate, selectivity of the masks etc. Further, the suitability of the used methods and etching masks were compared.
|
|
|
Nickel silicides layer by electron beam melting of electro deposited layer
Petr, Jiří ; Pantělejev, Libor (referee) ; Jan, Vít (advisor)
This master’s thesis deals with the possibility of creating a compact nickel-silicide layer on austenitic substrates. The theoretical part describes a variety of surface treatments, silicide division, and basic principles of electron beam. The experimental part contains a description of used experimental methods for evaluation of samples, creation of Ni-Si coating using electroplating, and the parameters of electron beam used for melting the sample coating. The last part is devoted to structural evaluation of the sample coating and its microhardness.
|
|
|
Anodic bonding of sandwich structures
Urbánek, Petr ; Kosina, Petr (referee) ; Pekárek, Jan (advisor)
This master thesis deals with the technology anodic soldering. It focuses mainly on soldering sandwich glass-silicon structures. Describes the soldering method and highlights its advantages. Theoretically discusses the different methods used soldering these structures and assess their possible benefits. This work explores practical ways possible soldering methods on a particular device. These different soldering methods evaluated on the basis of achieved quality connections. This thesis examines the anodic soldering at low temperatures, while there are demands on the shortening of the technological process.
|
guest ::
