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Quantum efficiency measurement of optoelectronic components and development of experimental equipment
Lipr, Tomáš ; Palai-Dany, Tomáš (referee) ; Macků, Robert (advisor)
This thesis deals with the issue of quantum efficiency measurement of optoelectronic devices. The physical nature of silicon solar cells is explained here. In addition, the quantum efficiency as a concept is introduced. There is also discussed the influence of a solar cell semiconductor structure on the quantum efficiency itself. Furthermore, the thesis is focused on the design of an experimental set-up for automated measurement and data acquisition. The final realization of the step motor control unit is described in detail. It includes local and/or remote operations, design and development motivation. The next chapter is dedicated to analysis of the Matlab source code for remote operation, data acquisition and presentation. The final part of the thesis gives attention to experiments with real structures, not only the solar cells. The obtained results of analyzed measurements are presented at the conclusion.
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Capacitance measurement of high-voltage PN junctions
Derishev, Anton ; Kosina, Petr (referee) ; Boušek, Jaroslav (advisor)
The work deals with the capacitance measurement of high-voltage PN junctions. The work is divided into theoretical and practical parts. The theoretical part presents insight into the fundamental properties of PN junctions and methods for measuring of the capacitance of PN junctions, primarily by C-V measurement. In the practical part, several kinds of measuring circuits are introduced and a suitable method of measurement is found. The calculations of basic parameters - the width of the base and resistivity are presented and discussed. The results were compared with the values obtained by calculation from the technological parameters of the junction.
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Photovoltaic systems
Fenyvesi, Aurel ; Kudela, Libor (referee) ; Toman, Filip (advisor)
The aim of the bachelor thesis was to provide a comprehensive overview of photovoltaic systems, their applications, and to present possible directions for their development. The thesis has a research character. It is presented in five chapters. First chapter explains the usability of solar radiation. Second chapter describes the photovoltaic cell, its principles of operation, electrical properties and defines four generations of development. Next chapter characterizes the different parts of photovoltaic systems. Fourth chapter defines the types of photovoltaic systems and their applications. The last, fifth chapter provides more detailed analyses of possible directions of development of photovoltaic cells, as well as, whole systems.
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Design of a laboratory equipment focused on measuring a PV panel at different temperatures
Moravčík, Daniel ; Báňa, Jiří (referee) ; Šedina, Martin (advisor)
The bachelor's thesis deals with the temperature dependence of the performance of a photovoltaic cell and the method of regulating its temperature. He also deals with the design and implementation of a laboratory element used to regulate the temperature of the photovoltaic cell in the laboratory. The theoretical part discusses the principle of photovoltaic cells and their electrical parameters, as some of them are the subject of measurement for which the device is made. The theoretical part then deals mainly with the influence of the surrounding environment on the performance of cells and their cooling methods in practice. The practical part itself describes the design and manufacture of a laboratory element for temperature regulation used to adjust the temperature of a photovoltaic cell, focusing first on the electrical design and then on the structural design. Finally, the work is devoted to the verification of the function of the manufactured device, when the accuracy of the device is determined.
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Semiconductor microstructures for cellular photostimulation
Tvrdoňová, Anna ; Weiter, Martin (referee) ; Glowacki, Eric Daniel (advisor)
Peroxid vodíku (H2O2) je metastabilní reaktivní forma kyslíku, která reguluje mnoho biologických drah. Úloha H2O2 v biologických procesech závisí na jeho lokální koncentraci, v malém množství (nM) může působit jako signální molekula, zatímco vyšší koncentrace mohou mít cytotoxické účinky. Cílem této práce bylo vytvoření fotosenzitivních mikročástic, které by produkovaly fyziologické množství peroxidu vodíku pro regulaci signálních drah v kultivovaných buňkách. Navrhované mikročástice jsou organické fotovoltaické struktury bez substrátu, které produkují H2O2 fotofaradickou redukcí molekulárního kyslíku. Produkce peroxidu probíhá za současné oxidace donoru elektronů přítomného v elektrolytu. Částice mají rozměry v řádu mikrometrů, zatímco jejich tloušťka nepřekračuje 100 nm. Fotofaradické reakce jsou poháněny červeným světlem (660 nm), které může pronikat tkáněmi, což umožňuje potenciální aplikace mikročástic in vivo. Práce se bude zabývat optimalizací výroby mikročástic a charakterizací produkce H2O2.
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Design of a photovoltaic power system with battery storage for household purposes in area of Brno-mesto
Vrana, Martin ; Vanýsek, Petr (referee) ; Vaněk, Jiří (advisor)
Táto bakalárska práca sa zameriava na rešerš technológií obsiahnutých v návrhu fotovoltického systému, ako sú solárne panely, nabíjateľné akumulátory, a systémy na premenu elektrickej energie. Následne sú tieto informácie využité na návrh hybridného a sieťového fotovoltického systému pre rodinný dom nachádzajúci sa v lokalite Brno-Mesto. Plán realizácie je nájsť cenovo výhodné riešenie s rozumným časom návratnosti, ktoré prevažne pokryje energetický odber domácnosti. Takisto sú náklady každého zo systémov znížene o dostupné štátne dotácie podľa parametrov každej inštalácie. Sieťový systém je lacnejší ako hybridný systém, pretože systém neobsahuje drahé batérie. Preto má nižšiu dobu návratnosti šiestich rokov, v porovnaní so siedmimi rokmi v prípade hybridného systému. Hybridný systém je výhodný, pretože umožňuje lokálne ukladanie energie a poskytuje záložné napájanie v prípade výpadku prúdu. Dodávateľ elektriny umožňuje uložiť prebytočnú energiu vyrobenú systémami do virtuálnej batérie, z ktorej je možné počas roka čerpať v čase nedostatočnej výroby energie. V kombinácii so súčasnými vysokými cenami energie majú oba systémy relatívne krátke obdobie finančného bodu zvratu v porovnaní so systémami v minulosti. Finálny výber typu inštalovaného systému je na klientovi.
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Diagnostic of semiconductor materials by EBIC method
Davidová, Lenka ; Máca, Josef (referee) ; Čudek, Pavel (advisor)
Master´s thesis is focused on diagnostics of semiconductor materials by EBIC method (measuring of currents induced beam), determination of the lifetime of minority carriers, or their diffusion length. The theoretical part is aimed at the principle of scanning electron microscopy, the characteristic properties of the microscope and the signals generated by the interaction of the primary electron beam with the sample. The thesis describes a structure of semiconducting silicon, band models, types of lattice defects and doped of semiconductor structures. After that it is described the theory of calculation of the diffusion length of minority carriers in semiconductors of type N and P. The aim of the experiment part of the thesis is to measure the properties of the semiconductor structure by EBIC and determination of diffusion length and lifetime of minority charge carriers based on the measured data The aim of the experiment part of the thesis is to measure the properties of the semiconductor structure by EBIC and determination of diffusion length and lifetime of minority charge carriers on the basis of the measured data.
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Market survey of high power semiconductor devices
Gama, Richard ; Adámek, Martin (referee) ; Boušek, Jaroslav (advisor)
In this thesis I will evaluate few discrete devices and their differences in structure, static and switching characteristics and also some structurall and manufacturing principles. After that I will follow up with their integration into power modules , where I will also aim on construction solutions and trends. These power moduls are today delivered as „stack“ or „system“, where for optimization and highest achievable efficiency of the whole unit the integration of protection, drive and cooloing stage is incorporated. Cooling and drive of some devices will be subject of a separate chapter. Also some of novel materials, which are very promissing, will be introduced. They show improvemnet in electrical and thermal properties. They have potential to replace the currently dominant Silicon in the near future.
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Design of VA-characteristic meter
Štěpnička, Martin ; Szabó, Zoltán (referee) ; Steinbauer, Miloslav (advisor)
The thesis describes the design of a measuring device volt-ampere characteristics of PN junction suitable for measuring characteristics of stabilizing diodes. Describes the basic principle of PN junction and related events. Part of the text discusses how to minimize the adverse parasitic effects. Furthermore, the proposal deals with an AC adapter suitable for this device. With that analyzes marginally rectifiers, stabilizers and filters. The following is a description of the device for measurement, principle of communication with the computer and the method of data processing. The annex contains schematic design, printed circuit boards and part list.
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