21. August 2014 at 15 in Physicums aud B103 will defend Siim Pikker his doctoral theses in physics "Modification in the emission and spectral shape of photostable fluorophores by nanometallic structures"
Dr. Rünno Lõhmus, Institute of Physics, University of Tartu
Dr. Ilmo Sildos, Institute of Physics, University of Tartu
Dr. Leonid Dolgov, Institute of Physics, University of Tartu
Professor Gintautas Tamulaitis, Head of Semiconductor Physics Department, Vilnius University, Lithuania
Summary:The dissertation studied the effects of small metallic nanoparticles and nanostructures on the emission of fluorescent materials. Special type of metallic particles and structures were used in the experiments, which could support electron density waves also known as plasmons. How these waves are excited and how these plasmon waves can be applied in practice falls under the new and quickly growing scientific research field called plasmonics. The study analysed the fluorescent properties of samarium containing titanium oxide and 140 nanometre sized nitrogen containing fluorescent nanodiamonds. The study employed various microscopic and spectroscopic measurements.
The results of the experiments showed that it is possible to apply metallic nanostructures to enhance the emission of high refractive index photostable fluorescence materials. It was also demonstrated that plasmonic nanostructures can modify other properties of the emission such as the polarization and spectral shape.
The work was focused to these high refractive index photostable fluorescent materials as they possess great importance to the high-tech industry, but there were only a few studies dealing with the emission and spectral modifications effects induced by metallic nanostructures in similar materials. The results of the study help us to better understand the interactions of metallic nanostructures with fluorophores which can lead to engineering of more efficient fluorescent materials and new composite optical devices.