Search for dissertations about: "Luminescence quenching"
Showing result 1 - 5 of 25 swedish dissertations containing the words Luminescence quenching.
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1. Unravelling Sensitisation and Quenching Pathways in Lanthanide Luminophores
Abstract : Lanthanide (Ln) ions find use in cellular detection and probing of many analytes, owing to their unique photophysical properties. However, to make the Ln emission efficient, one has to develop a light-harvesting antenna, which is an organic chromophore that absorbs and transfers energy to the Ln. READ MORE
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2. Energy Transfer Processes and Quenching Pathways in Lanthanide Complexes: The Role of Structural Changes
Abstract : Due to their unique magnetic and luminescent properties, trivalent lanthanides (Ln(III)) have been widely utilised in cellular imaging. Ln(III) luminescence is usually sensitized by a light-harvesting ‘antenna’, a chromophore that can transfer the excitation energy to the Ln(III). READ MORE
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3. Dynamic local structural symmetries and luminescence properties of the yellow emitting phosphor Ce3+-doped Y3Al5O12
Abstract : This thesis centers on investigations of the local structure and vibrational properties of the oxide garnet Y3Al5O12 (YAG), which when substituted with a few percent of the activator ion Ce3+ to replace Y3+ (Y3−xCexAl5O12, YAG:Ce3+) is one of the most important phosphors for solid state lighting. The study builds on a comprehensive analysis of the nature of the phonons and localized vibrational modes in YAG:Ce3+ and how these depend on the Ce3+ concentration and temperature and how they affect key optical properties, such as the intensity and frequency of the emitted light. READ MORE
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4. Understanding the interactions between vibrational modes and excited state relaxation in garnet structured phosphors
Abstract : This thesis concerns investigations of the local structural environments and vibrational dynamics of the three garnet type oxide phosphors Ce3+-doped Y3Al5O12 (YAG:Ce3+), Ca3Sc2Si3O12 (CSS:Ce3+), and Sr3Y2Ge3O12 (SYG:Ce3+), which show promising optical properties as luminescent materials used in solid state white lighting technologies. The study focuses on a comprehensive analysis of the nature of the long-range vibrations (phonons) in terms of local atomic and molecular motions of the garnet structure, as well as their dependence on the nature of the garnet chemical composition, Ce3+ concentration and temperature. READ MORE
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5. Secondary chlorophyll a luminescence decay kinetics from green algae and higher plants : mechanisms and application
Abstract : Barley protoplasts were shown to be a suitable experimental system for studies on the relative maximum during the decay of luminescence observed in most photosynthetic systems after excitation with far red light and in the presence of O2. The far red induced relative luminescencemaximum was shown to be a result of three coinciding events:*Randomization of the S-states of the water splitting system during illumination with far red light. READ MORE