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.

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.

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

prof. RNDr. Pavel Tománek, CSc.

1. Absorption properties of thermal plasma

   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.

2. Composites for electrical insulations for higher voltages with increased reliability

   The subject of the research will be dielectric properties of composites 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, eventually more complex chemical formulations. The presence of various types and sizes of microparticles with dimensions of some 10 – 20 microm favorably affects the withstand capability of composites to partial discharges and electrical treeing and, hence, the breakdown strength as well as the degradation resistance. This in turn brings the possibility to manufacture electrical equipment (e.g. switchgear, vacuum interrupters) with smaller dimensions and weight and improved reliability. An important issue concerning all composites is the presence of a large number of interfaces. They are to due to the presence of large amounts of particles with complex shapes (neither planar nor spherical). These interfaces exhibit a low stability, which may later cause substantial changes of electrical properties in the course of ageing. One of the objectives of the proposed research would therefore be to study the behavior of electrically insulating composites in the course of accelerated ageing. The work on this topic will require experimental work in sample preparation and design, studies of the relation between microphysical structure and electrical properties and the measurement of electrical properties of developed material systems. Equipment currently available in the Department of Physics: measurement equipment for the frequency range 10^(-2) – 10^9 Hz (Alpha-AT high-resolution impedance analyzer) and Janis helium cryostat CCS-400/204 for the temperature range 10 – 500 K, as well as established software for measurement control. Also available is Nicolet 8700 FTIR-spectrometer with wave number range 20 000 – 350 cm-1.

   Tutor: Liedermann Karel, doc. Ing., CSc.

3. Electronic nose based on analysis of current fluctuations

   Thesis deals with a study of elctronic noise in order to develop a non-traditional technique for evaluation of output sensor signal considering direct component and also its fluctuation. 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, i.e noise. Motivation is not only increase of selectivity and sensitivity but also possibility of electronic noise development. The aim is to analyze dependencies of these fluctuations on input quantity by measurements of noise characteristics (spectral density of noise current) and transport characteristics.

   Tutor: Sedlák Petr, doc. Ing., Ph.D.

4. Methods for 3D distance measurement

   Size measurement of the object is becoming important together with progress of 3D printing technology, navigation systems and various portables devices. There exist several approaches for distance measurement suitable for particular applications with different resolution, measurement range and speed of measurement. The work will be focused on possibilities of particular method utilization in mobile devices.

   Tutor: Škarvada Pavel, Ing., Ph.D.

5. RTS noise in nanoelectronic structures

   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.

6. Solar cell defect isolation

   Defects in the solar cell structures negatively affects cell parameters. Defect localization in the microscale region is the first step for the defect elimination. The aim of the work is application of the focused ion beam and other methods for defect elimination and study defect removal procedure influence on the semiconductor device parameters.

   Tutor: Škarvada Pavel, Ing., Ph.D.

7. Source characterization of electromagnetic emission using signal features

   Thesis deals with a study of electromagnetic emission (EME) signals and description of their features in order to experimental study of degradation processes, leading to total destruction of model specimens under mechanical loading, and localization of these processes. EME signals are of stochastic nature and are processed by similar principles as those, which are used in speech recognition. Motivation is an exact evaluation of materiál behavior under test. Aim of the work is determination of appropriate signal features of emission events in time domain, frequency domain and time-frequency domain.

   Tutor: Sedlák Petr, doc. Ing., Ph.D.

8. Study of dielectric and insulating materials with high permittivity, based on titanate ceramics

   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

   Tutor: Liedermann Karel, doc. Ing., CSc.

9. Study of dielectric and insulating materials with low permittivity

   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 paths 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).

   Tutor: Liedermann Karel, doc. Ing., CSc.

10. Utilization of electromagnetic emission for monitoring of processes in rocks

    Electromagnetic emissions (EME) arises during mechanical loading of solids. EME anomalies under natural conditions can be observed in association to tectonic loading, stress re-distribution and crack propagation prior to earthquake or in relation to gravitational mass movements. EME can be measured by various types of antennas and it is possible to perform monitoring of the above mentioned phenomena based on this measurement. The goal will be development of a methodology for measuring and processing of EME for use in predicting of earthquakes and other selected events and possibly to distinguish between different types of these phenomena. Long-term measurements of EME in caves in the Czech Republic and in the Alps in Austria will be carried out for this purpose and the results will be compared with results from other methods used in geology. Analysis of EME signals origin and propagation in studied materials and design and verification of advanced methods for measured signals processing and evaluation will be an important part of the work. The Ph.D. student will cooperate on the scientific research collaboration with the Institute of Rock Structure and Mechanics of the ASCR and with Department of Geology, Naturhistorisches Museum Wien, Austria.

    Tutor: Koktavý Pavel, prof. Ing., CSc. Ph.D.