Modification in the emission and spectral shape of photostable fluorophores by nanometallic structures
Date
2014-07-05
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Abstract
Uurimus kuulub uudsesse ja kiiresti arenevasse plasmoonika valdkonda, mis tegeleb plasmonitega ehk elektrontiheduse lainetega seotud nähtustega. Doktoritöös selgitati, kuidas mõjutavad metallist (kullast ja hõbedast) nano-osakesed ja struktuurid helendavatest materjalidest pärinevat valgust. Peamiselt analüüsiti samaariumit sisaldava titaanoksiidi ja lämmastikku sisaldavate 140 nanomeetri suuruste teemantide kiirguse muutumist. Uurimuses rakendati peamiselt fluorestsents-mikroskoopia ja spektroskoopia meetodeid.
Katsete tulemused näitasid, et kullast ja hõbedast nano-osakesed suudavad teatud tingimustel helendavatest materjalidest pärinevat valgust võimendada. Peale selle selgus, et peale valguse võimendamise on nende plasmonlainetega võimalik kontrollida ka valguse teisi omadusi, nagu näiteks valguse polarisatsiooni või spektri kuju ehk värvi.
Doktoritöö uudsus seisnes selles, et seal näidati, et plasmonlainete kasulike omadusi saab rakendada ka helendavate materjalide peal, millel on kõrge murdumisnäitaja ja mis ei kaota võimet valgust kiirata. Kuigi need fluorestseerivad materjalid on kõrgtehnoloogiatööstusele väga olulised, oli plasmonite mõju seda tüüpi materjalidele varem vähe uuritud. Neid materjale saab näiteks kasutada valgustites, laserites, biotehnoloogias, optikatööstuses ja optiliste elektroonikaseadmete valmistamise juures ning isegi katseliste kvantarvutite ehitamisel.
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.
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.
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Väitekirja elektrooniline versioon ei sisadla publikatsioone.
Keywords
plasmoonika, nanoosakesed, fluorestsentsspektroskoopia, plasmonics, nanoparticles, fluorescense spectroscopy