|
|
Microstructural Defects of Solar Cells Investigated by a Variety Diagnostics Methods
Škvarenina, L’ubomír
This paper discusses the application of a variety diagnostic methods applicable to the solar cells. More objective results about solar cells quality and reliability are possible to obtain by using a various methods. Diagnostic methods described in this paper are based on a dark and illuminated J–V characteristics, a investigation of noise in a wide range of frequency and a radiation detection at a di erent spectral range, namely by an electroluminescence and a thermography method. These methods are primarily more appropriate for a detection or a localization of microstructure defects when a reverse-bias stress is applied. However, the analysis of a forward-bias conditions is included in an investigation of J–V characteristics as well.
|
|
| |
|
|
Modification of inks for luminescent panels
Foldynová, Klára ; Dzik, Petr (referee) ; Vala, Martin (advisor)
This bachelor thesis deals with the study of the influence of luminescent additives on the features of printed electroluminescent elements. The goal of the thesis is to find a strategy for expanding the color spectrum of these elements while maintaining their functionality. An important step was the addition of additive to the basic luminescent layer of ZnS and its influence on emission of radiation. A change of color spectrum was proved by usage the U111 fluorophore and in particular the wavelength change and the intensity of the radiation on the input voltage and frequency were observed. The obtained results can be used in further studies to extend the knowledge of electroluminescence.
|
|
|
Material prinitng of electroluminiscent panel
Guricová, Patrícia ; Dzik, Petr (referee) ; Vala, Martin (advisor)
This works deals with the preparation of luminescent lamp using screen printing method, characterization of individual layers and the study of spectral properties, influenced by changing printing parameters. In theoretical part are described the principles of electroluminescence as well as the method of preparation of the luminiscent lamp. Experimental part involves optimazing of printing parametres, so the homogenneous light emission is achieved. Furthermore, the influence of the change in the number of layers of active material and dielectric on the light output of the panel at the lowest working voltage is studied. The result of this work is a funcional electroluminescence lamp and an optimazed process for its preparation.
|
|
|
Influence of temperature on light-technical parameters of LED
Sláma, Pavel ; Štěpánek, Jaroslav (referee) ; Pavelka, Tomáš (advisor)
This thesis deals with LEDs and how temperature influences their parameters. In the first part it is analyzed how semiconductors and semiconductor junctions work, which is fundamental for understanding mechanisms of diodes. Next up is description of electroluminescence and basic description of physical principles, on which it works. Following part is supposed to introduce reader to electro-technical parameters and powering possibilities of LEDs. Following chapter focuses on description of lightning-technical parameters. It aims to describe their meaning and their relation to LEDs. Next part is about influence of temperature. Firstly, it names the parameters which are altered by temperature change. Follows the description of thermal management and its influence on right behavior of LED diodes. The last part contains construction of measuring workplace for analyzing temperature influence on lightning-technical parameters of LEDs. Measurement of chosen electrical and lightning parameters follows up.
|
|
|
Degradation of Photovoltaic Modules
Poledník, Tomáš ; Křivík, Petr (referee) ; Vaněk, Jiří (advisor)
The bachelor diploma thesis is focused on the constructional technology of the solar modules as well as on the problems of the induced degradation under the influence of the potential. It specifies the key issues and possible elements that influence the effect of environment with regard to possible causes of the origin of degeneration. The thesis includes the description of measuring of the polycrystalline and monocrystalline technologies that are resistant to the leading potential. Furthemore, the measuring was carried out on the chosen testing pieces that had been affected by the degradation of the output
|
|
|
Microscopic analysis of silicon solar cells defects
Brukner, Jakub ; Solčanský, Marek (referee) ; Stojan, Radek (advisor)
This thesis deals with detection of defects solar cells using method electroluminescent, electron microscope and subsequent 3D modeling of areas with defects and structure of the solar cell. In the text are describe basic methods for detection of defects appearing in solar cells. Also some basic defects which can be made during manufacture are there describe. For better orientation the basic principle of functionality and manufacturing process is included.
|
|
|
Operating Characteristics of LED Sources
Brdečko, Aleš ; Diviš, Daniel (referee) ; Baxant, Petr (advisor)
This semester thesis is dealing with issues of LED (light emiting diod).In the text we can find general summary knowledges about LED, relating their history, construction, principle of working and also treatise about of semiconductor compounds. In thesis are given examples of use indicating their advantages and disadvantages and indicating their parameters. The practical content of this thesis is evaluation of measurement performed on some samples of LED especially graphics addiction of crosses and V-A characteristics measured in addiction on current.
|
|
|
Analyse of photovoltaic solar cells by the photoluminescence method
Richter, Vladimír ; Bača, Petr (referee) ; Vaněk, Jiří (advisor)
This diploma thesis deals with the issues of photovoltaic cells. The main aim of this thesis is to introduce the principles of operation of solar cells and methods of detection of defects affecting their quality. The first part is about the functional properties of silicon cells and it also examines the possibilities of detecting the defects of these structures. It also describes the most commonly used modern diagnostic methods. In the next part, practical tests of photovoltaic cells using the methods electroluminescence and photoluminescence are performed. These methods are based on the excitation of luminescence radiation of the silicon material by the external light source.
|
|
|
Long-term monitoring of parameters of photovoltaic modules
Kladiva, Roman ; Solčanský, Marek (referee) ; Gvritishvili, Roman (advisor)
This thesis deals with the influence of degradation mechanisms to change the parameters of photovoltaic panels. The aim of the study was the long-term monitoring of selected solar modules, comparing their parameters with measurements from previous years and the evaluation of degradation mechanisms on their properties. The theoretical part is focused on the description of the monitored parameters and defects Panel, are discussed measuring methods by which the modules were monitored. Experimental part then consists of measuring modules individual test methods. The measured values were subsequently constructed graphical dependence, and the results were compared with measurements from previous years. The last part of the thesis is devoted to evaluation of the degradation of PV modules.
|
guest ::
