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dc.contributor.advisorCheetham, Anthony K.
dc.contributor.authorFurman, Joshua D
dc.date.accessioned2010-12-21T16:20:02Z
dc.date.available2010-12-21T16:20:02Z
dc.date.issued2010-11-16
dc.identifier.citationLocal structure and time resolved luminescence of emulsion prepared YAG nanoparticles J. D. Furman, G. Gundiah, K. Page, N. Pizarro, A. K. Cheetham Chem. Phys. Lett. 465, 67-72 (2008); Relating Mechanical Properties and Chemical Bonding in an Inorganic-Organic Framework Material: A Single-Crystal Nanoindentation Study J. C. Tan and J. D. Furman and A. K. Cheetham J. Amer. Chem. Soc. 131, 14252-14254(2009); Tunable, ligand-based emission from inorganic-organic frameworks: A new approach to phosphors for solid state lighting J. D. Furman, A. Y. Warner, S. J. Teat, A. A. Mikhailovsky and A. K. Cheetham Chem. Mater. 22, 2255-2260 (2010); J. D. Furman, B. C. Melot, S. J. Teat, A. A. Mikhailovsky and A. K. Cheetham. “Towards enhanced ligandcentered photoluminescence in inorganic-organic frameworks for solid state lighting.” Phys. Chem. Chem. Phys., 2010;en_GB
dc.identifier.urihttp://www.dspace.cam.ac.uk/handle/1810/228686
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/228686
dc.description.abstractSolid state white light emitting diode lighting devices outperform conventional light sources in terms of lifetime, durability, and lumens per watt. However, the capital contribution is still to high to encourage widespread adoption. Furthermore, the colour from today's devices is unsuitable for general room illumination and thus new phosphor materials are needed. This dissertation will examine the synthesis of inorganic nanoparticles and the possibility of using hybrid inorganic-organic frameworks in the search for new lighting phosphors. Nanoparticles of the oxide compound yttrium aluminium garnet were synthesized using an emulsion technique, though it was found that the high temperature processing needed for good optical properties was not compatible with maintaining nanosized particles. In terms of hybrid framework phosphors, several aspects of this new area have been explored. The mechanical and optical properties of a dense cerium oxalate formate hybrid framework compound have been investigated. Its strength was found to be nearly as great as some classical ceramic compounds, and clearly robust enough for device applications. While the photoluminescence of the cerium oxalate formate was not suitable for solid state lighting, the impressive mechanical properties evaluated are expected to be valid for a wide range of dense inorganic-organic frameworks. A novel approach to solid state lighting phosphors was introduced by using ligand-based photoluminescence in hybrid frameworks. Novel frameworks were prepared using 9,10-anthraquinone-2,3-dicarboxylic acid in combination with calcium, manganese, nickel, and zinc. These compounds show excellent photoluminescent emission for use in solid state lighting applications, although the luminescence is quenched at room temperature due to dynamic effects. The excitation, while reaching the blue part of the spectrum, falls just short of what is needed for use today's devices. To address these issues, a second class of novel framework compounds was prepared using 9-fluorenone-2,7-dicarboxylic acid in combination with calcium, strontium, barium, cadmium, and manganese. They are more rigid structures and show good luminescence at room temperature with a photoluminescent excitation spectrum extending further into the blue than the anthraquinones. Additionally, quantum yield in the calcium fluorenone is nearly double that of its parent ligand, suggesting that there is an enhancement in luminescent properties as a result its inclusion in a framework structure. An explanation for the differences in efficiency between seemingly similar compounds are drawn from their compositions, crystal structures, photoluminescence, and specific heat properties. Finally, some structural and chemical targets for future hybrid phosphor development are identified based on the relationships identified in this work.en_GB
dc.description.sponsorshipThis work was supported by Mitsubishi Chemical Center for Advanced Materialsen_GB
dc.language.isoenen_GB
dc.rightsAll Rights Reserveden
dc.rights.urihttps://www.rioxx.net/licenses/all-rights-reserved/en
dc.subjectSolid state lightingen_GB
dc.subjectHybrid framework materialsen_GB
dc.subjectInorganic chemistryen_GB
dc.titleNovel phosphors for solid state lightingen_GB
dc.typeThesisen_GB
dc.type.qualificationlevelDoctoral
dc.type.qualificationnameDoctor of Philosophy (PhD)
dc.publisher.institutionUniversity of Cambridgeen_GB
dc.publisher.departmentDepartment of Materials Science and Metallurgyen_GB
dc.identifier.doi10.17863/CAM.14261


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