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Application of Scanning Probe Microscope in Nanoscience and Nanotechnology
Konečný, Martin ; Klapetek, Petr (oponent) ; Fejfar, Antonín (oponent) ; Bartošík, Miroslav (vedoucí práce)
This doctoral thesis is devoted to application of Scanning Probe Microscopy (SPM) in nanoscience and nanotechnologies with the main focus on advanced Atomic Force Microscopy (AFM) techniques, such as conductive AFM (cAFM), Kelvin Probe Force Microscopy (KPFM), and their utilization in graphene research. First, a brief introduction to SPM techniques is provided and followed by a review of recent application of AFM and KPFM in characterization of graphene and graphene-based devices. Further, the doctoral thesis introduces a novel approach to combine AFM with Scanning Electron Microscopy (SEM). The review leads to estimation of main topics of doctoral research. These topics cover a study of electrical communication between separated graphene sheets, electrical properties of hydrogenated graphene and characterization of graphene-metal nanostructures used for biosensing. The work is further focused on a demonstration of correlative AFM/SEM imaging and on a technical realization of advanced techniques on AFM specially designed for integration into SEM. Each topic is discussed and supported by relevant experimental results. Finally, the prospects of future research is outlined.
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Non-Destructive Local Diagnostics of Optoelectronic Devices
Sobola, Dinara ; Pína,, Ladislav (oponent) ; Pinčík,, Emil (oponent) ; Tománek, Pavel (vedoucí práce)
To obtain novel materials for emerging optoelectronic devices, deeper insight into their structure is required. To achieve this, the development and application of new diagnostic methods is necessary. To contribute to these goals, this dissertation thesis is concerned with local diagnostics, including non-destructive mechanical, electrical and optical techniques for examining the surface of optoelectronic devices and materials. These techniques allows us to understand and improve the overall efficiency and reliability of optoelectronic device structures, which are generally degraded by defects, absorption, internal reflection and other losses. The main effort of the dissertation work is focused on the study of degradation phenomena, which are most often caused by both global and local heating, resulting in increased diffusion of ions and vacancies in the materials of interest. From a variety of optoelectronic devices, we have chosen two representative devices: a) solar cells - a large p-n junction device, and b) thin films - substrates for micro optoelectronic devices. In both cases we provide their detailed surface characterization. For the solar cells, scanning probe microscopy was chosen as the principal tool for non-destructive characterization of surface properties. This method is described, and both positive and negative aspects of the methods used are explained on the basis of literature review and our own experiments. An opinion on the use of probe microscopy applications to study solar cells is given. For the thin films, two interesting, from the stability point of view, materials were chosen as candidates for heterostructure preparation: sapphire and silicon carbide. The obtained data and image analysis showed a correlation between surface parameters and growth conditions for the heterostructures studied for optoelectronic applications. The thesis substantiates using these prospective materials to improve optoelectronic device performance, stability and reliability.
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Study of Thin-Film Surfaces
Trivedi, Rutul Rajendra ; Fejfar, Antonín (oponent) ; Klapetek, Petr (oponent) ; Šikola, Tomáš (oponent) ; Čech, Vladimír (vedoucí práce)
doctoral thesis deals with the study of surface properties of single-layer and multilayer thin films deposited from of vinyltriethoxysilane and tetravinylsilane monomers. It also deals with adhesion characterization of single layer tetravinylsilane films. The plasma polymerized thin films were prepared under steady-state deposition conditions on polished silicon wafers using plasma-enhanced chemical vapor deposition. The surface properties of the films were been characterized by different scanning probe microscopy methods and nanoindentation techniques such as conventional depth-sensing nanoindentation and load-partial-unload (cyclic) nanoindentation. While, the nanoscratch test was used to characterize the film adhesion properties. Single layer films prepared at different deposition conditions were characterized with respect to surface morphology and mechanical properties (Young’s modulus and hardness). The results of surface morphology, grain analysis, nanoindentation, finite elemental analysis and modulus mapping helped to know the hybrid nature of single layer films that were deposited at higher powers of RF-discharge. A novel approach was used in surface characterization of multilayer film by scanning probe microscopy and nanoindentation. The adhesion behavior of plasma polymer films of different mechanical properties and film thickness were analyzed by normal and lateral forces, friction coefficient, and scratch images obtained by atomic force microscopy.
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Application of Scanning Probe Microscope in Nanoscience and Nanotechnology
Konečný, Martin ; Klapetek, Petr (oponent) ; Fejfar, Antonín (oponent) ; Bartošík, Miroslav (vedoucí práce)
This doctoral thesis is devoted to application of Scanning Probe Microscopy (SPM) in nanoscience and nanotechnologies with the main focus on advanced Atomic Force Microscopy (AFM) techniques, such as conductive AFM (cAFM), Kelvin Probe Force Microscopy (KPFM), and their utilization in graphene research. First, a brief introduction to SPM techniques is provided and followed by a review of recent application of AFM and KPFM in characterization of graphene and graphene-based devices. Further, the doctoral thesis introduces a novel approach to combine AFM with Scanning Electron Microscopy (SEM). The review leads to estimation of main topics of doctoral research. These topics cover a study of electrical communication between separated graphene sheets, electrical properties of hydrogenated graphene and characterization of graphene-metal nanostructures used for biosensing. The work is further focused on a demonstration of correlative AFM/SEM imaging and on a technical realization of advanced techniques on AFM specially designed for integration into SEM. Each topic is discussed and supported by relevant experimental results. Finally, the prospects of future research is outlined.
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Non-Destructive Local Diagnostics of Optoelectronic Devices
Sobola, Dinara ; Pína,, Ladislav (oponent) ; Pinčík,, Emil (oponent) ; Tománek, Pavel (vedoucí práce)
To obtain novel materials for emerging optoelectronic devices, deeper insight into their structure is required. To achieve this, the development and application of new diagnostic methods is necessary. To contribute to these goals, this dissertation thesis is concerned with local diagnostics, including non-destructive mechanical, electrical and optical techniques for examining the surface of optoelectronic devices and materials. These techniques allows us to understand and improve the overall efficiency and reliability of optoelectronic device structures, which are generally degraded by defects, absorption, internal reflection and other losses. The main effort of the dissertation work is focused on the study of degradation phenomena, which are most often caused by both global and local heating, resulting in increased diffusion of ions and vacancies in the materials of interest. From a variety of optoelectronic devices, we have chosen two representative devices: a) solar cells - a large p-n junction device, and b) thin films - substrates for micro optoelectronic devices. In both cases we provide their detailed surface characterization. For the solar cells, scanning probe microscopy was chosen as the principal tool for non-destructive characterization of surface properties. This method is described, and both positive and negative aspects of the methods used are explained on the basis of literature review and our own experiments. An opinion on the use of probe microscopy applications to study solar cells is given. For the thin films, two interesting, from the stability point of view, materials were chosen as candidates for heterostructure preparation: sapphire and silicon carbide. The obtained data and image analysis showed a correlation between surface parameters and growth conditions for the heterostructures studied for optoelectronic applications. The thesis substantiates using these prospective materials to improve optoelectronic device performance, stability and reliability.
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Study of Thin-Film Surfaces
Trivedi, Rutul Rajendra ; Fejfar, Antonín (oponent) ; Klapetek, Petr (oponent) ; Šikola, Tomáš (oponent) ; Čech, Vladimír (vedoucí práce)
doctoral thesis deals with the study of surface properties of single-layer and multilayer thin films deposited from of vinyltriethoxysilane and tetravinylsilane monomers. It also deals with adhesion characterization of single layer tetravinylsilane films. The plasma polymerized thin films were prepared under steady-state deposition conditions on polished silicon wafers using plasma-enhanced chemical vapor deposition. The surface properties of the films were been characterized by different scanning probe microscopy methods and nanoindentation techniques such as conventional depth-sensing nanoindentation and load-partial-unload (cyclic) nanoindentation. While, the nanoscratch test was used to characterize the film adhesion properties. Single layer films prepared at different deposition conditions were characterized with respect to surface morphology and mechanical properties (Young’s modulus and hardness). The results of surface morphology, grain analysis, nanoindentation, finite elemental analysis and modulus mapping helped to know the hybrid nature of single layer films that were deposited at higher powers of RF-discharge. A novel approach was used in surface characterization of multilayer film by scanning probe microscopy and nanoindentation. The adhesion behavior of plasma polymer films of different mechanical properties and film thickness were analyzed by normal and lateral forces, friction coefficient, and scratch images obtained by atomic force microscopy.
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