Akademik Veri Yönetim Sistemi
Tezin Türü: Doktora
Tezin Yürütüldüğü Kurum: Dokuz Eylül Üniversitesi, Fen Bilimleri Enstitüsü, Türkiye
Tezin Onay Tarihi: 2022
Tezin Dili: İngilizce
Öğrenci: BEYZA YILDIRIM
Danışman: Kadriye Ertekin
Özet:
Phosphors are commercially important chemicals because they are used as raw
materials in mobile phones, personal computers, LCD screens, light emitting diode
(LED) and white light emitting diode (WLED) technologies. In this thesis,
commercially available phosphors of Lu3Al5O12:Ce3+ (LuAG:Ce3+),
(Y,Gd)3Al5O12:Ce3+ (YAG:Ce3+) and CaAlSiN3:Eu2+ (CASN:Eu2+) were investigated
to enhance their spectral properties rather than the known approaches. The green,
yellow and red phosphors were chosen to represent a large spectral range available in
the screen technologies as well as LED applications. All phosphors were prepared in
thin film form in a polymethyl methacrylate (PMMA) matrix. The light harvesting
materials of nano-scale ZnO and CuO, have been used to improve the spectral
properties of the LuAG:Ce3+ and YAG:Ce3+
. In this process, fluorescence,
phosphorescence, and excited state lifetimes were monitored and promising
experimental results were obtained. Mechanisms indicating possible energy transfers
between the species have been revealed. In the second part of the thesis, the energy
transfer between phosphors and Tris (1,10-phenanthroline) ruthenium (II)
hexafluorophosphate dye (Ru(phen)3PF6) has been investigated. The binary blends of
the LuAG:Ce3+, YAG:Ce3+ and CASN:Eu2+ with the Ru(phen)3PF6 exhibited
promising results in the presence of the ionic liquid (IL). Long-term photo stabilities
of the composites supported with the IL were investigated during 8 months. No
significant effect of the IL on photo-stability levels was detected.
Keywords: LuAG:Ce3+, YAG:Ce3+, CASN:Eu2+
, phosphor, Ruthenium complex,
ionic liquid, LED, WLED, photoluminescence, fluorescence, phosphorescence