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Development of a method for simultaneous measurement of cathodoluminescence and topography of nanostructures
Vacek, Martin ; Klok, Pavel (referee) ; Nováček, Zdeněk (advisor)
The bachelor thesis focuses on the combined use of SPM and SEM techniques using an optical fiber used to collect cathodoluminescence radiation. The thesis contains of a section summarising the used techniques with more detailed description of the cathodoluminescence phenomenon. Following sections describe the development of the method, including the design and construction of the probe, tuning fork and optical fibre modifications. The results show that the newly developed method is capable of providing accurate and reliable results, thus contributing to the expanded capabilities of nanostructure characterization at the Institute of Physical Engineering.
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Optoelectronic characterization of perovskite materials and their application in photovoltaics
Ulč, Filip ; Konečný, Martin (referee) ; Klok, Pavel (advisor)
This bachelor's thesis is focused on a detailed correlative study of optoelectronic perovskite materials through advanced measurement techniques employed at the Institute of Physical Engineering. These techniques include surface charge measurement and time-resolved photoluminescence mapping. Currently, there are few publications or articles attempting to analyze optical and electrical processes using more than two techniques simultaneously. Therefore, the aim of this thesis is to expand the knowledge of existing techniques and enhance them by incorporating surface charge analysis (in the dark and under illumination) using Kelvin Probe Force Microscopy (KPFM). The contribution of this work to the study of perovskite materials lies in correlative measurements that provide new insights into the arrangement and movement of charge carriers, which can be utilized in the research of perovskite solar cells.
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Design and development of a multifunctional compact device for correlative measurement of temperature-dependent photoluminescence spectra of perovskite CsPbBr3
Balabán, Martin ; Klok, Pavel (referee) ; Liška, Petr (advisor)
This work presents an experimental setup for measuring the temperature dependence of the photoluminescence response of CsPbBr3 perovskite nanocrystals. The work includes the design, fabrication, optimization and especially the implementation of the device to an existing spectrometer. Furthermore, this thesis deals with the characterization part, which involves sample preparation and actual measurements of temperature-dependent photoluminescence. The constructed device enables photoluminescence measurements with a temperature range of 50 °C to 60 °C. Furthermore, thanks to the implementation of the device in the design of a confocal microscope with a raster stage, it is possible to obtain a map of the photoluminescence response of CsPbBr3 nanocrystals at any temperature in the given range. Each photoluminescence spectrum was parameterized and a simplified linear model based on the exciton-phonon coupling principle was used to determine the temperature dependence of the photoluminescence line width. Finally, the measured data are compared with existing measurements and the advantages and limitations of our constructed device are evaluated.
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2D near-field digital holography
Klok, Pavel ; Kvapil, Michal (referee) ; Dvořák, Petr (advisor)
This bachelor’s thesis presents an experimental study of the phase distribution of the surface plasmon polaritons (SPPs) interference by using an aperture-type Scanning Near-field Optical Microscope (a-SNOM). Interference patterns caused by the excitation of SPPs waves on variously arranged grooves were detected and compared with FDTD simulations. Using the 2D Near-field Phase-Shifting Digital Holography (NPDH) method, phase distribution in individual interference nanostructures was imaged and later compared to the results obtained from FDTD simulations.
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Near-field excited photoluminescence mapping
Klok, Pavel ; Ledinský, Martin (referee) ; Dvořák, Petr (advisor)
Tato práce se zabývá mapováním fotoluminiscence (PL) pomocí buzení blízkého pole (NF), které slouží ke zkoumání optoelektronických vlastností v nanometrovém měřítku. Díky překonání omezení tradičních optických technik v dalekém poli zkoumá jevy na menších rozměrech, které by jinak byly nedostupné. Hlavní důraz je kladen na NF rastrovací optickou mikroskopii, která umožňuje pozorování poddifrakčních jevů u studovaných vzorků. Významným přínosem této práce je zavedení časově rozlišitelného mapování PL v NF, tedy průlomové metody pro studium dynamických procesů pod hranicí difrakce. Tento přístup představuje nový přínos pro tento obor, což potvrzuje i přehled literatury uvedený v této práci. Díky pečlivému vyhodnocení a interpretaci měření PL tato práce rozšiřuje naše znalosti o optických vlastnostech olovnatých halogenidových perovskitů a jejich potenciálních aplikacích např. pro solární články. Dále odhaluje dosud neprozkoumané možnosti v oblasti časově rozlišitelného mapování PL v NF a poskytuje dosud nevídaný náhled do dynamických procesů pod difrakčním limitem. Posunutím hranic optického výzkumu na úrovni nanorozměrů vytváří tato diplomová práce základ pro nové směry zkoumání v této oblasti.
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2D near-field digital holography
Klok, Pavel ; Kvapil, Michal (referee) ; Dvořák, Petr (advisor)
This bachelor’s thesis presents an experimental study of the phase distribution of the surface plasmon polaritons (SPPs) interference by using an aperture-type Scanning Near-field Optical Microscope (a-SNOM). Interference patterns caused by the excitation of SPPs waves on variously arranged grooves were detected and compared with FDTD simulations. Using the 2D Near-field Phase-Shifting Digital Holography (NPDH) method, phase distribution in individual interference nanostructures was imaged and later compared to the results obtained from FDTD simulations.
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