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Pi-conjugated molecules exhibiting singlet fission
Sahuľ, Martin ; Kratochvíl, Matouš (referee) ; Vala, Martin (advisor)
This bachelor thesis focuses on characterisation of novel materials designed for use in future generation of photovoltaic cells. Examined materials were derivates of diketopyrollopyroles, in which the process of singlet fission was confirmed. Using fluorescence reference standards, the correctness of research methodology was confirmed. Measurements of basic optical and fluorescence characteristics such as absorption, excitation and emission spectra, wavelengths of their respective maximum values and quantum yields were made. Since the studied materials only differed in the number of bromine atoms, the effect of bromation on the properties of molecules was discussed from the acquired values. It was found, that substituted bromine atoms increase the excitation and emission wavelengths of diketopyrollopyroles, therefore decreasing the energy needed to excite the molecule. Next, a new method using fluorescence measurements in a magnetic field that can be used for a quick analysis of singlet fission was developed. Measurements made using this method confirmed the occurrence of singlet fission in rubrene as well as in studied materials. Performed measurements gathered new useful information for the design of new molecules and further improvement of the developed method.
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Pi-conjugated molecules exhibiting singlet fission
Sahuľ, Martin ; Kratochvíl, Matouš (referee) ; Vala, Martin (advisor)
This bachelor thesis focuses on characterisation of novel materials designed for use in future generation of photovoltaic cells. Examined materials were derivates of diketopyrollopyroles, in which the process of singlet fission was confirmed. Using fluorescence reference standards, the correctness of research methodology was confirmed. Measurements of basic optical and fluorescence characteristics such as absorption, excitation and emission spectra, wavelengths of their respective maximum values and quantum yields were made. Since the studied materials only differed in the number of bromine atoms, the effect of bromation on the properties of molecules was discussed from the acquired values. It was found, that substituted bromine atoms increase the excitation and emission wavelengths of diketopyrollopyroles, therefore decreasing the energy needed to excite the molecule. Next, a new method using fluorescence measurements in a magnetic field that can be used for a quick analysis of singlet fission was developed. Measurements made using this method confirmed the occurrence of singlet fission in rubrene as well as in studied materials. Performed measurements gathered new useful information for the design of new molecules and further improvement of the developed method.
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