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Study of the optical properties of titanium dioxide thin films
Rackovská, Anna Patrícia ; Schmiedová, Veronika (referee) ; Zmeškal, Oldřich (advisor)
The bachelor thesis is focused on the acquirement of thin film layers optical properties characterisation methods, done on inject printed titanium dioxide layers deposed on soda lime glass. Its main emphasis was on spectroscopic ellipsometry that was used to determine the refractive indices and the extinction coefficients of the samples in range of wavelengths from 200 nm to 850 nm and layer thickness. This thesis also shows another options of thin film layers preparation and several other methods to characterise properties of samples, specifically optical microscopy, used to set sample boundary as rough, mechanical profilometry which defined thickness of layers in range of 80 nm for the most thin sample to 250 nm for the most thick sample, and UV-VIS spectroscopy.
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Study of optical properties of thin films of perovskite MAPbBr3 precursors
Rackovská, Anna Patrícia ; Schmiedová, Veronika (referee) ; Zmeškal, Oldřich (advisor)
This diploma thesis is focused on preparation of perovskite methylammonium lead bromide thin film layers and also thin film layers of its precursors, namely methylammonium bromide and lead(II) bromide, by spin-coating from the solution; and optical characterisation of the prepared thin film layers by UV-VIS spectroscopy and spectroscopical ellipsometry. Methylammonium bromide does not absorb in visible nor ultraviolet region, the maximum absorption of lead(II) bromide occurred in ultraviolet region, methylammonium lead bromide absorbs in visible region. Optical band gaps were determined by Tauc method to (3,5 ± 0,1) eV for lead(II) bromide and 2,15 eV, respectively 2,25 eV for perovskite. Refractive indices and extinction coefficients were determined by ellipsometry in range of wavelengths from 290 nm to 830 nm and their dependence with layer thickness was discussed. Ellipsometry model used in this thesis consist on Tauc-Lorentz oscillators for methylammonium bromide, methylammonium lead bromide and partially for lead(II) bromide, which another part is formed by New Amorphous oscillator.
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Study of refractive index dispersion dependences with using of interference microscopy
Schmiedová, Veronika ; Veselý, Michal (referee) ; Zmeškal, Oldřich (advisor)
The master´s thesis deals with the study of optical properties of thin transparent layers on the organic materials (PPV, P3HT, TiO2, DPP) and especially with the determination of dispersion dependences of refractive index of prepared thin layers. In the theoretical part there are described principles of deposition thin layers of the analyzed materials and their properties. In addition, there are also described methods of optical properties measurements (optical and interference microscopy and ellipsometry). The combination of interference microscope with digital camera was used for determination of refractive index. The image analysis was used for the determination of parameters (with help of the software HarFA). The images of thin layers surfaces were analyzed from the side of the metal contact as well as from the side of glass. In conclusion, there are presented results of the refractive index of the thin layers obtained from the measured values.
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Study of optical properties of thin films of organic photovoltaic cells
Čuboň, Tomáš ; Schmiedová, Veronika (referee) ; Zmeškal, Oldřich (advisor)
This master´s thesis is focused on measurement of optical properties of thin layer of materials used in organic solar cells (OSC). The usage of graphene oxides and its reduced forms as parts of hole transport layer (HLT) in OSC were studied. At the beginning of the thesis, there is described basic theory necessary to understand the optical properties of thin layers. The thin layer deposition and reduction of GO are discussed too. The experimental part is aimed to the optical characterization of prepared thin films. The results from optical microscopy, UV-VIS spectroscopy, FT-IR spectroscopy and spectroscopic ellipsometry were obtained. At the end of the thesis, the results are concluded and compared with already published literature.
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Study of the optical properties of graphene oxide thin films
Smolková, Denisa ; Zmeškal, Oldřich (referee) ; Schmiedová, Veronika (advisor)
This thesis examines the preparation of thin layers and determining their optical properties. It is focused on graphene oxide. In the theoretical part, basic information about the thin layers and their preparation is supplied. That is followed by a description of various methods of determining their optical properties and properties of light. Experimental part and results are focused on the preparation of thin layers by spin-coating and evaluation of measured values using optical microscopy, profilometry, spectroscopic ellipsometry and UV VIS spectroscopy. The conclusion summarizes the results of these methods.
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Study of Optical Properties and Interference Phenomena on Thin Films of Organic Mcaterials
Schmiedová, Veronika ; Čeppan, Michal (referee) ; Mistrík, Jan (referee) ; Zmeškal, Oldřich (advisor)
Ph.D. thesis is focused on the study and determination of layer thickness and optical properties, such as the dispersion dependence of the refractive index of various materials prepared in the form of thin layer. In the first part of this work the theoretical findings in the field of spectroscopic ellipsometry are summarised. These findings are followed by the description and characterization of the light polarization, evaluation of experimental data and determination of the physical properties of studied materials. Experimental and result section of this work is devoted to the preparation and characterization of thin films of the studied materials: titanum dioxide (TiO2), new organic materials (MDMO-PPV, PCDTBT, PCBTDPP, PC60BM, PC70BM) and reduced graphene oxide (rGO). These were all selected with respect to their potential use in the organic photovoltaics.
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Study of thin transparent films properties
Schmiedová, Veronika ; Veselý, Michal (referee) ; Zmeškal, Oldřich (advisor)
The main aim of this bachelor´s thesis is a study of thin transparent layers of organic materials (PPV, P3HT, TiO2, DPP). The theoretical part describe the methods of quality examinations of their surface, mostly the use of optical and interference microscopy. For elaboration of data was used the image analysis via HarFA program. Thickness of layer and the index of refraction was provided by interference microscope. From the interference images was identified the amplitude of groove for various values of treshold, but mainly the interface inhomogenity of groove, which proofs the surface inhomogenity of samples. For the images taken by the optical microscope were allocated the average errors (but also errors of superior sorts) defining the surface inhomogenities of samples. The conlusion of this study compare the results of both methods.
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Study of optical properties of thin films of perovskite MAPbBr3 precursors
Rackovská, Anna Patrícia ; Schmiedová, Veronika (referee) ; Zmeškal, Oldřich (advisor)
This diploma thesis is focused on preparation of perovskite methylammonium lead bromide thin film layers and also thin film layers of its precursors, namely methylammonium bromide and lead(II) bromide, by spin-coating from the solution; and optical characterisation of the prepared thin film layers by UV-VIS spectroscopy and spectroscopical ellipsometry. Methylammonium bromide does not absorb in visible nor ultraviolet region, the maximum absorption of lead(II) bromide occurred in ultraviolet region, methylammonium lead bromide absorbs in visible region. Optical band gaps were determined by Tauc method to (3,5 ± 0,1) eV for lead(II) bromide and 2,15 eV, respectively 2,25 eV for perovskite. Refractive indices and extinction coefficients were determined by ellipsometry in range of wavelengths from 290 nm to 830 nm and their dependence with layer thickness was discussed. Ellipsometry model used in this thesis consist on Tauc-Lorentz oscillators for methylammonium bromide, methylammonium lead bromide and partially for lead(II) bromide, which another part is formed by New Amorphous oscillator.
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Study of the optical properties of graphene oxide thin films
Smolková, Denisa ; Zmeškal, Oldřich (referee) ; Schmiedová, Veronika (advisor)
This thesis examines the preparation of thin layers and determining their optical properties. It is focused on graphene oxide. In the theoretical part, basic information about the thin layers and their preparation is supplied. That is followed by a description of various methods of determining their optical properties and properties of light. Experimental part and results are focused on the preparation of thin layers by spin-coating and evaluation of measured values using optical microscopy, profilometry, spectroscopic ellipsometry and UV VIS spectroscopy. The conclusion summarizes the results of these methods.
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Study of the optical properties of titanium dioxide thin films
Rackovská, Anna Patrícia ; Schmiedová, Veronika (referee) ; Zmeškal, Oldřich (advisor)
The bachelor thesis is focused on the acquirement of thin film layers optical properties characterisation methods, done on inject printed titanium dioxide layers deposed on soda lime glass. Its main emphasis was on spectroscopic ellipsometry that was used to determine the refractive indices and the extinction coefficients of the samples in range of wavelengths from 200 nm to 850 nm and layer thickness. This thesis also shows another options of thin film layers preparation and several other methods to characterise properties of samples, specifically optical microscopy, used to set sample boundary as rough, mechanical profilometry which defined thickness of layers in range of 80 nm for the most thin sample to 250 nm for the most thick sample, and UV-VIS spectroscopy.
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