Přístupnostní navigace
E-application
Search Search Close
Branch Details
Original title in Czech: Fyzikální elektronika a nanotechnologieFEKTAbbreviation: PP-FENAcad. year: 2013/2014
Programme: Electrical Engineering and Communication
Length of Study:
Profile
The objective of the study is to provide PhD education to MSc graduates in all partial fields and to create a cross-disciplinary overview of the present development, to develop theoretical foundations in the selected research area, to master the methods of scientific, to develop their creative abilities and to use them for the solution of research problems. This all should lead to a dissertation thesis, which will provide an original a significant contribution to the research status in the field of interest.
Key learning outcomes
Graduates of this program will acquire cross-disciplinary knowledge of and experience in technical and physical subjects on a high-quality theoretical level. Graduates are for their later independent research and development work equipped with the knowledge and experience from, in particular, physics of semiconductors, quantum electronics and mathematical modeling and will be able to independently solve problems associated with nanotechnologies. Potential job careers: research worker in basic or applied research and in the introduction, implementation and application of new prospective and economically beneficial procedures and processes in the field of electronics, electrical engineering, non-destructive testing and reliability and material analysis.
Occupational profiles of graduates with examples
Graduates of this program will acquire cross-disciplinary knowledge of and experience in technical and physical subjects on a high-quality theoretical level. Graduates are for their later independent research and development work equipped with the knowledge and experience from, in particular, physics of semiconductors, quantum electronics and mathematical modeling and will be able to independently solve problems associated with nanotechnologies. Potential job careers: research worker in basic or applied research and in the introduction, implementation and application of new prospective and economically beneficial procedures and processes in the field of electronics, electrical engineering, non-destructive testing and reliability and material analysis
Guarantor
prof. RNDr. Pavel Tománek, CSc.
Issued topics of Doctoral Study Program
An important role in many plasma processing devices plays the radiative heat transport. The experimental investigation is very difficult, therefore, mathematical modeling is of great imporatnce. The knowledge of absorption properties of the plasma is necessary for succesfulI theoretical modeling. The aim of this disertation work is to collect atomic and molecular data which will serve as input data for calculation of absroption coefficients of selected plasmas. It concerns searching of data in available web databases, their computer processing, and creation of own databases in the form of input files for further calculations.
Tutor: Bartlová Milada, doc. RNDr., Ph.D.
A large number of inhomogeneities and defects appear in solar cells during their manufacturing due to their large surface area. They reduce quality of cells and cause decrease of their efficiency during operation in solar panels. The aim of the work will be measurement and analysis of these solar cell loss-making mechanisms both at edges and in the volume of samples by monitoring of their activities during electrical or optical excitation. The study will be mainly focused on the characteristics of radiation emitted in the forward and reverse direction during electrical excitation (spectroscopy in the visible region by a CCD camera, infrared spectroscopy, a thermo camera), current fluctuations during voltage loading, local study of surface properties (LBIC, electron microscopy) and other characteristics. The description of different types of loss-making mechanisms in silicon solar cells and their effect on the efficiency of solar cells and panels will be proposed on the basis of this study. The Ph.D. student will cooperate on the research projects SIX (Sensor, Information and Communication Systems) and CEITEC (Central European Institute of Technology).
Tutor: Koktavý Pavel, prof. Ing., CSc. Ph.D.
Electromagnetic emission (EME) and acoustic emission (AE) methods are modern methods to study the generation and behavior of micro-cracks. The EME and AE signals appear during cracks generation when a solid is exposed to mechanical loading. Suitably designed methodology of EME and AE signals measurement, processing and evaluation allows obtaining the useful information about the processes taking place in the cracks formation in solids. The main goal of this work will extend the newly designed experimental set-up of the modern methods of measured signals spectral analysis in order to properly describe the analyzed signals in the time-frequency domain. The EME and AE signals can be described (outside the initial pulse) as narrow-band signals and so these methods will focus on the analysis of narrowband signals in broadband noise background. An appropriate description is meant to use such types of transformation or projection that are able to describe (as the most accurate way) the amplitude and frequency changes of each harmonic components of analyzed narrowband signal. Another area of interest will be the application of appropriate methods for time localization of events in the background noise. These are specialized methods that can determine the formation of individual events from spectral analysis in the time-frequency domain. The Ph.D. student will cooperate on the research project GAČR P104/11/0734 (Utilization of electromagnetic and acoustic emission in research of advanced composite materials for structural applications) and the projects SIX (Sensor, Information and Communication Systems) and CEITEC (Central European Institute of Technology).
The goal of the thesis will be a study of methods for diagnostics and characterization of material defects in macro- and microscale. The digital camera data as well as the images from scanning probes microscopes will be studied and processed and be correlated to existing electric and optical methods.
Tutor: Tománek Pavel, prof. RNDr., CSc.
Nanocomposites are another current trend in materials research, which starts in recent years more and more exercise. Nanocomposites are a two-phase material consisting of a polymer matrix and reinforcing phase, at least one dimension falls within the nanometer range. Nanočásti are added to the paint in order to improve some parameters of the basic material and are now used in a very wide range of industries.
Tutor: Holcman Vladimír, doc. Ing., Ph.D.
Fiber-optic sensors offers wide spectrum of applications nowadays. These sensors have such advantages as lightweight, avoidance of ground loops, capability of responding to a wide range of measurands, resistance to chemical corrosion, high temperature, high sensitivity, large bandwidth, and immunity to electromagnetic interference. Thus fiber-optic sensors are used as accelerometers, thermometers, humidity sensors, chemical and biochemical sensors. Theme of the thesis focuses on an usage of the sensors for material diagnostics and structure health monitoring. The aim of the work is to develop and to implement an optic system, which would serve, e.g. for detection of partial discharges in power transformers.
Tutor: Sedlák Petr, doc. Ing., Ph.D.
In order to predict the mechanical behaviour of a composite during its service life, it is important to evaluate its mechanical response under different types of external stresses by studying the initiation and development of cracks and the effects induced by damage and degradation.Passive methods NDT, such as acoustic emission and electromagnetic emission, offer huge great potential due to their ability of quantitative evaluation such as source location and a source characterization. The thesis is focused on study of degradation processes in selected composite materials under mechanical stress using electromagnetic and acoustic emissions. Special attention will be oriented to the evaluation methodology of signals of electromagnetic and acoustic emission, where a key step is to define appropriate signal features of emission events in time domain, frequency domain and time-frequency domain, and is to find appropriate methods for dimensional reduction, which is always critical to the application of cluster analysis.
Subject of doctoral thesis will be non-destructive study of defect regions in the structure of modern Cu(InGa)Se2 thin-film solar cells. These heterojunction materials have a very high absorption coefficient and the associated conversion efficiency of optical energy. The total thickness of the functional structure is about 3 µm and it is very sensitive to the presence of local and bulk defects reducing efficiency and lifetime. By studying of these defects can be pointed out valuable information about loss mechanisms, electric charge transport phenomena and technological precaution can be proposed for their elimination. For diagnostics purposes will be used several methods such as monitoring of radiation by means of infrared and CCD camera, response monitoring to local irradiation, the microscopic study of surface topography, specific surface modification by ion beam and measuring of voltage or current fluctuations etc.
The main problem in the process of the solar cell conversion efficiency and service life improving is to find their basic parameters. A lot of methods exist for this purpose but they often give different results. The goal of the work will be research of advanced modern methods for important parameters finding for example quantum efficiency, minority charge carrier lifetime, impact ionization coefficients or impurities concentration profiles in PN junctions and others. Obtained results will be used for these parameters measuring for some types of solar cells, primarily monocrystalline, polycrystalline and amorphous Si solar cells and CIGS cells. The Ph.D. student will cooperate on the research projects SIX (Sensor, Information and Communication Systems) and CEITEC (Central European Institute of Technology).
Exploatation of electronic noise for the estimation of passive components quality and reliability. The assesment of the correlation between electronic noise level and the results of accelerating ageing tests.
Tutor: Sedláková Vlasta, doc. Ing., Ph.D.
Radiation energy transfer influences significantly physical processes occuring in the plasma, it plays important role in many devices in plasma processing devices. Electric arc plasmas are utilized in number of industrial applications, e.g. in plasma metallurgy, waste treatment, plasma cutting, welding or spraying. The goal of the work is to solve the equation of radiation transfer by means of the approximate method of discrete ordinates (SN-approximation), to compare the obtained results of radiation energy and radiation flux for selected kinds of plasmas with known results obtained by other approximate methods (method of partial characteristics, diffusion approximation), to discuss availability of different approximate methods.
The aim of this project is to determine parameters of traps in insulation layer of HFET/HEMT structures by analysis of its noise characteristics, mainly RTS (random telegraph signal) noise. Experimental work is based on measurement of temperature dependence of noise using helium cryostat and study of amplitude and mean time of capture and emission as a function of electric field intensity and charge carrier concentration in channel. These results will be used to improve generation-recombination model of noise origin and localization of traps.
Tutor: Pavelka Jan, doc. Mgr., CSc. Ph.D.
The objective of the research is the investigation of electrical properties of CCTO ceramics (i.e., based on CaCu3Ti4O12), doped with transition metals and lanthanides. Attention will be focused toward the identification of mechanisms leading to high dielectric constant (permittivity) of the order 10^4 – 10^5 and, subsequently, on the modification of CCTO ceramics formulation in order to reduce dielectric loss and to extend the frequency interval, in which the dielectric constant retains its high value, up to the GHz range Materials exhibiting high permittivity are needed for new applications, particularly in integrated circuits and in capacitors. In capacitors, high-k dielectrics are used in order to attain higher energy densities and thus to reduce the size of capacitors themselves. The work on this topic will require experimental work in sample preparation and design, studies of the theory of high -k dielectrics and the measurement of electrical properties of developed material systems. What is available: measurement equipment for the frequency range 10^2 – 10^9 Hz and Janis helium cryostat CCS-400/204 for the temperature range 10 – 500 K. Also available are Novocontrol ALPHA-AT high-resolution high-frequency analyzer with frequency range 3 μHz – 40 MHz and Nicolet 8700 FTIR-spectrometer with wave number range 20 000 – 350 cm^(-1).
Tutor: Liedermann Karel, doc. Ing., CSc.
Decreasing the dimensions in integrated circuits (currently 32 nm) brings about an increase of interconnect capacitance and thus the reduction of the signal propagation speed. The limiting factor for a further improvement of electronic device performance thus become not the properties of semiconductor devices themselves but rather interconnect delays and, hence, too, high magnitudes of parasitic capacitances. One of the options for the reduction of interconnect capacitances is the reduction of the permittivity (dielectric constant, k) of thin-layer insulating layers (capacitance is directly proportional to permitivity). Two major routes are available: replacement of polar Si-O bonds with less polar Si-F or Si-C bonds or raising the porosity (intentional introduction of air voids). The newly developed low-k materials must, however, not limit the currently used silicon technologies and must be able to pass all manufacturing steps (temperatures up to about 1100 °C). The work on this topic will require experimental work in sample preparation and design, studies of the theory of low-k dielectrics and the measurement of electrical properties of developed material systems. What is available: measurement equipment for the frequency range 10^(-3) – 10^9 Hz and Janis helium cryostat CCS-400/204 for the temperature range 10 – 500 K. Also available are Novocontrol ALPHA-AT high-resolution high-frequency analyzer with frequency range 3 μHz – 40 MHz and Nicolet 8700 FTIR-spectrometer with wave number range 20 000 – 350 cm^(-1).
Due to stochastic nature of the matter, physical processes in materials are considered to be stochastic, and they reveal as fluctuation of measurable quantities macroscopically. Not only in sensorsics, these fluctuations are usually called noise, since they are assumed to be unwanted and distracting components, which do not carry any information. However, fluctuation mechanisms can also give useful pieces of information about physical or chemical processes occurred in a sensor. Several authors demonstrated that noise measurement and its evaluation may represent an approach of extracting more selective response from sensors. The aim is to analyze dependencies of these fluctuations on concentrations of detected substances by measurements of noise characteristics (spectral density of noise current) and transport characteristics. Experimental and theoretical studies will be provided and will be bases in a design of detection criteria and in an incorporation of a new algorithm based on Support Vector Machine for the processing of nonlinear effects that are observed in the detection of gases.
Examination of fetus heartbeat is usually done periodically after 30th week of pregnancy. The analysis of heartbeat and uterine contractions represents a safe method for fetus examination before childbirth. The aim of the work lies in a choice of suitable acoustic emission set-up and also in experimental measurements of relevant amount of pregnant women.
Micro-cracks creation in mechanical loaded solids is accompanied by origin of electromagnetic (EME) and acoustic (AE) signals. These signals may be used for study of micro-cracks formation evolution, their characteristics finding and their localization. EME and AE methods are usable in electrical engineering, mechanical engineering, civil engineering or in geophysics. The goal will be determination of micro-cracks primary parameters and their localization in concrete, granite and in modern composite materials for structural applications. Analysis of EME and AE signals origin and propagation will be performed in these materials and models will be suggested. The methodology for determination of selected primary parameters and micro-cracks localization will be suggested and verified. The solution of hydraulic press control via PC and realization of automated set-up will be an important part of the work. The Ph.D. student will cooperate on the research project GAČR P104/11/0734 (Utilization of electromagnetic and acoustic emission in research of advanced composite materials for structural applications) and the projects SIX (Sensor, Information and Communication Systems) and CEITEC (Central European Institute of Technology).
The subject of the research will be dielectric properties of nanocomposites for electrical insulation. These materials are based on thermosetting resins, mostly epoxides, containing finely dispersed SiO_2, TiO_2, Al_2O_3 or WO_3 microfillers and nanofillers, eventually more complex chemical formulations. The presence of nanoparticles with dimensions of some 10 – 20 nm favorably affects the withstand capability of nanocomposites to partial discharges and electrical treeing and, hence, the breakdown strength as w