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Luminescence of semiconductors studied by scanning near-field optical microscopy
Těšík, Jan ; Klapetek, Petr (referee) ; Křápek, Vlastimil (advisor)
This work is focused on the study of luminescence of atomic thin layers of transition metal chalkogenides (eg. MoS2). In the experimental part, the work deals with the preparation of atomic thin layers of semiconducting chalcogenides and the subsequent manufacturing of plasmonic interference structures around these layers. The illumination of the interference structure will create a standing plasmonic wave that will excite the photoluminescence of the semiconductor. Photoluminescence was studied both by far-field spectroscopy and near-field optical microscopy.
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Interaction of group III and IV metals with Si(100) surface in temperature range from 20 to 800K
Setvín, Martin ; Ošťádal, Ivan (advisor) ; Janda, Pavel (referee) ; Klapetek, Petr (referee)
1 Title: Interaction of group III and IV metals with Si(100) surface in temperature range from 20 to 800 K Author: Martin Setvín Department: Departement of Surface and Plasma Science Supervisor of the doctoral thesis: Doc. RNDr. Ivan Ošt'ádal CSc. Abstract: Interaction of group III and IV metals with Si(100) surface was studied by STM (Scanning Tunneling Microscopy) and AFM (Atomic Force Microscopy) in temperature range from 20 to 800 K. Adsorption and hopping of single metal adatoms on Si(100)-c(4×2) reconstruction can be observed by STM at low temperatures. Activation energies and frequency prefactors for hopping of single indium atoms were measured by two meth- ods - direct STM measurement at low temperature and Kinetic Monte Carlo simulations of layer growth at room temperature. Group III and IV atoms self-assemble into single atom wide chains on Si(100) surface at about room temperature. Atomic and electronic structure of the chains was investi- gated by means of STM and dynamic non-contact AFM. Keywords: Si(100), STM, AFM, adsorption, diffusion
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Design and Realization of the Second Generation Imaging Reflectometer and its Application in Optical Analysis of Thin Films
Vodák, Jiří ; Držík,, Milan (referee) ; Klapetek, Petr (referee) ; Ohlídal, Miloslav (advisor)
The work deals with a technique of imaging spectroscopic reflectometry developed at The Institute of Physical Engineering, Brno University of Technology. The technique is well suited for characterization of samples non–uniform along their surfaces. The technique is primarily used for optical characterization of thin films. First part of the work is focused on basic physical principles of the technique and on ways in which measurement data are obtained. It contains a basic description of evaluating methods and a basic concept of an imaging spectroscopic reflectometer with a description of main parts of such a device. The main part of the work is focused on a description of two devices which were built at The Institute of Physical Engineering together with a description of some of upgrades which were implemented to these devices during their development. A description of measurements done with the two devices is also included. Last part of the work is then focused on further development of the technique. Intention of possible evolution of the technique to imaging spectroscopic ellipsometry is proposed.
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Surface topography and mechanical properties of thin films on tetravinylsilane basis
Plichta, Tomáš ; Klapetek, Petr (referee) ; Čech, Vladimír (advisor)
Proposed diploma thesis is focused on preparation and characterization of the plasma polymer thin films based on tetravinylsilane monomer (TVS). Plasma enhanced chemical vapour deposition (PECVD) method involving pulse and continual plasma discharge modes were used for thin film deposition on silicon wafer pieces. Reactive plasma composition was containing pure TVS or mixtures of TVS and argon or oxygen gas. Atomic force microscopy was used for surface topography and roughness characterization. Cyclic nanoindentation was involved to measurements to determine the Young’s modulus and hardness of prepared films and scratch test was performed to evaluate the degree of adhesion. Special attention was drawn to the characterization of films with a Young’s modulus below 10 GPa. Tip geometry of indenter influence on scratch test was also commented. Surface and mechanical properties of thin films in relation to the deposition conditions were correlated to the obtained results and final analysis of deposition conditions influence is proposed.
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Application of Interferometry in VT UHV SPM
Šulc, Dalibor ; Klapetek, Petr (referee) ; Fejfar, Antonín (referee) ; Spousta, Jiří (advisor)
The thesis is aimed at the development of Scanning Probe Microscopes (SPM). It describes design and development of modular controll electronics to be applied eectively on more microscopes SPM. Control electronics consist of stabilized power source, high–voltage amplier and probe signal amplier. The open–source project GXSM has been introduced. It contains a logic control unit which controls scanning, acquiring data and feedback control. GXSM provides a graphical user interface based on linux operation system. Second part of the thesis is aimed at design and development of interferometric deection sensing system for SPM cantilevers and applications at SPM in general. Designed interferometer has been assembled and tested. It can clearly distinguish a signal of amplitude 2 nm. At the end of the thesis the design of interferometric system implementation is presented.
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Design of Low-Temperature Ultra High Vacuum Scanning Probe Microscopes
Pavera, Michal ; Klapetek, Petr (referee) ; Vetushka, Aliaksei (referee) ; Šikola, Tomáš (advisor)
This thesis deals with the development of scanning probe microscopes. Mechanical requirements for microscopes using measuring methods of scanning tunneling microscopy (STM) and atomic force microscopy (AFM) under enviroments of an ultrahigh vacuum (UHV) and variable temperatures are specified. Mechanical designs of two microscopes are discussed and their control electronics described. A special chapter is devoted to description of linear piezo manipulators and mechanical design of these prototypes.
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Surface and Mechanical Properties of Thin Films
Pálesch, Erik ; Klapetek, Petr (referee) ; Skuhurov,, Andrey (referee) ; Čech, Vladimír (advisor)
The doctoral thesis deals with the study of morphology and mechanical properties of thin plasma polymer films based on tetravinylsilane monomer and its mixtures with oxygen and argon. Thin films were prepared by plasma-enhanced chemical vapour deposition on silicon and glass substrates. Atomic force microscopy was used for characterization of thin film surface and for depiction of composite interphase with functional interlayer. Mechanical properties of thin films, namely Young’s modulus and hardness, were studied by cyclic nanoindentation technique. Nanoindentation device was also used to carry out scratch test, which was helpful to describe adhesion of films to substrate. In this thesis the influence of deposition conditions on surface and mechanical properties of thin films prepared in continual and pulse wave on planar substrates is discussed. Also, the suitability of few atomic force microscopy techniques for depiction of composite interphase was reviewed.
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Study of Thin-Film Surfaces
Trivedi, Rutul Rajendra ; Fejfar, Antonín (referee) ; Klapetek, Petr (referee) ; Šikola, Tomáš (referee) ; Čech, Vladimír (advisor)
Disertační práce se zabývá studiem povrchových vlastností jedno a vícevrstvých filmů deponovaných z vinyltriethoxysilanových a tetravinylsilanových monomerů. Zabývá se také charakterizací adheze jednovrstvých filmů z tetravinylsilanu. Plazmaticky polymerizované tenké vrstvy byly připraveny na leštěných křemíkových substrátech pomocí plazmové depozice z plynné fáze za ustálených podmínek. Povrchové vlastnosti vrstev byly charakterizovány pomocí různých metod rastrovací sondové mikroskopie a nanoindentačních technik jako je konvenční a cyklická nanoindentace. Vrypový test byl použit pro charakterizaci vlastností adheze vrstev. Jednovrstvé filmy připravené za různých depozičních podmínek byly charakterizovány s ohledem na povrchové morfologie a mechanické vlastností (modul pružnosti, tvrdost). Výsledky morfologie povrchu, analýzy zrn, nanoindentace, analýzy konečných prvků a modulů mapování pomohly rozlišit hybridní charakter filmů, které byly deponovány při vyšších výkonech RF-výboje. Nový přístup byl použit v povrchové charakterizaci vícevrstvého filmu pomocí rastrovací sondové mikroskopie a nanoindentace. Adhezívní chování plazmaticky polymerizovaných vrstev různých mechanických vlastností a tloušťek bylo analyzováno pomocí normálních a laterálních síl, koeficientu tření, a snímků vrypů získaných pomocí mikroskopie atomárních sil.
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Surface analysis of xGnP/PEI nanocomposite
Červenka, Jiří ; Klapetek, Petr (referee) ; Čech, Vladimír (advisor)
Tato Diplomová práce se zabývá povrchovou analýzou nanokompozitní folie polyetherimidu (PEI) vyztuženého exfoliovanými grafitickými nanodestičkami (xGnP). Analyzovány byly take vzorky nevyztužené PEI folie a samostatné nanodestičky. Vzorky nanokompozitu a PEI folie byly plazmaticky leptány s využitím argonového plazmatu po dobu 1, 3 a 10 hod. Skenovací elektronová mikroskopie (SEM) byla použita pro charakterizaci samostatných nanodestiček rozptýlených na křemíkovém substrátu, původních či leptaných vzorků PEI folie a nanokompozitu. Nanodestičky byly identifikovány při povrchu leptané nanokompozitní folie. Mikroskopie atomárních sil (AFM) byla použita pro zobrazení povrchové topografie separovaných nanodestiček a odkrytých destiček při povrchu leptaného kompozitu. Povrchová drsnost (střední kvadratická hodnota, vzdálenost nejnižšího a nejvyššího bodu) leptaného nanokompozitu narůstala s prodlužující se dobou leptání. Akustická mikroskopie atomárních sil (AFAM) byla použita pro charakterizaci elastické anizotropie leptaných kompozitních vzorků. Nanoindentační měření umožnila charakterizaci lokálních mechanických vlastností PEI a nanokompozitních folií.
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Adhesion characterization of thin plasma-polymer films
Pálesch, Erik ; Klapetek, Petr (referee) ; Čech, Vladimír (advisor)
The diploma thesis deals with characterization of adhesion of plasma polymer films deposited on silicon wafers. The samples included organosilicon thin films based on tetravinylsilane monomer prepared by plasma-enhanced chemical vapour deposition. Scratch test was used to characterize film adhesion employing nanoindentation measurements. Adhesion of plasma polymer films of different mechanical properties and film thickness was analyzed by normal and lateral forces, friction coefficient, and scratch images obtained by scanning probe microscope working in atomic force microscopy mode.
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