Browsing by Subject "Time-resolved photoluminescence"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    The synergistic effect of Er3+and Ho3+on temporal color tuning of upconversion emission in a glass host: Via a facile excitation modulation technique for anti-counterfeiting applications
    (Royal Society of Chemistry, 2020) Erol E.; Kibrisli O.; Vahedigharehchopogh N.; Çelikbilek Ersundu M.; Ersundu A.E.
    Lanthanide-doped upconversion luminescent materials are highly promising for diverse applications, e.g., solid-state lighting, volumetric displays, and anti-counterfeiting, owing to their unique optical feature of color-tunable emission under near-infrared excitation. Hence, in this study, emission color tuning of Er3+/Ho3+ ions in a fixed glass host is investigated via a facile excitation modulation technique. The upconversion emission color from green to yellowish is tuned successfully by regulating the frequency of the irradiation source. The population and depopulation rates of related transitions are investigated through time-resolved photoluminescence and Judd-Ofelt analysis in order to elucidate the proposed mechanism of color tuning. Upconversion quantum yield values are measured in the range of 0.12 to 0.17% for a better comparison of the emission properties. Additionally, thermal, and structural properties are investigated to reveal the favorable properties of the selected tellurite glass host. Ultimately, several patterns are designed and constructed by a screen-printing technique using powdered glass to demonstrate its suitability as a multicolor imaging method for anti-counterfeiting applications. The temporal color tuning of upconversion emission via a facile excitation modulation technique in a glass host clearly indicates that the proposed Er3+/Ho3+ co-doped glasses can be potentially applied in the state-of-the-art technologies, especially for anticounterfeiting purposes. © the Owner Societies.
  • No Thumbnail Available
    Item
    Photoluminescence and decay characteristics of cerium, gallium and vanadium - containing borate-based bioactive glass powders for bioimaging applications
    (Elsevier Ltd, 2021) Deliormanlı A.M.; Oguzlar S.; Ertekin K.
    Biomaterials having photoluminescent properties play a crucial role in real-time bioimaging after in vivo implantation. In this study, photoluminescence properties and decay characteristics of the borate-based 13–93B3 glasses containing different concentrations of cerium, gallium, and vanadium oxides were investigated for biomedical applications. The borate-based bioactive glass powders were prepared using melt-quench technique and size reduction was performed through planetary ball milling. Bioactivity of the prepared powders was investigated in simulated body fluid at 37 °C under static conditions. The photoluminescent properties and decay kinetics of the as-prepared and the SBF-treated bioactive glass powders were analyzed by steady-state and time-resolved photoluminescence measurements. Results revealed that the cerium activated glasses exhibited an intense luminescence centered at 538 nm. Broad-band emission of the gallium and vanadium doped samples was centered at 440 and 572 nm, respectively. All of the SBF-treated glasses exhibited enhanced lifetimes and bi-exponential decays both in nanosecond and microsecond regime measurements. It was concluded that depending on the dopant concentration, bioactive glass particles prepared in the study showed remarkable photoluminescence and have potential to be used in bioimaging applications. © 2020 Elsevier Ltd and Techna Group S.r.l.