Tunable optical properties and DFT calculations of RE3+ codoped LaBO3 phosphors

2019-12-01
In this study, single phase DyxLa1-xBO3, DyxCeyLa1-x-yBO3, DyxEuyLa1-x-yBO3, and TbxCeyLa1-x-yBO3 phosphors were successfully synthesized through the microwave assisted solid state method with urea. Synthesized compounds were characterized by X-Ray Diffraction, Fourier Transform Infrared spectroscopy, Scanning Electron Microscope, and Fluorescence spectroscopy. Thermal stabilities of the phosphors were studied with temperature dependent fluorescence measurements. In addition, density functional theory calculations were performed to investigate preferential Dy3+ ion doping sites in LaBO3 lattice. The findings of the study revealed over ten times increase in the emission intensities of phosphors were observed with Ce3+ codoping. The highest luminescence intensities were recorded for Dy0.09Ce0.05La0.86BO3 and Tb0.07Ce0.05La0.88BO3 phosphors. Furthermore, energy transfers were supported by luminescence lifetime measurements. Temperature dependent fluorescence measurements showed their thermal stabilities. According to the CIE 1931 color space, the colors of the Dy3+ only doped, Ce3+/Dy3+; Ce3+/Tb3+ and Dy3+/Eu3+ codoped phosphors were determined as off-white, white, green and yellow-orange, respectively. Intensities of the bands and the colors of the phosphors can be tuned with the choice of codopant ions or with adjustments in their concentration ratio.
OPTICAL MATERIALS

Suggestions

Tunable optical properties and DFT calculations of RE3þcodoped LaBO3 phosphors
Abacı, Özde Ceren; Esentürk, Okan (2019-12-01)
In this study, single phase DyxLa1-xBO3, DyxCeyLa1-x-yBO3, DyxEuyLa1-x-yBO3, and TbxCeyLa1-x-yBO3 phosphors were successfully synthesized through the microwave assisted solid state method with urea. Synthesized com-pounds were characterized by X-Ray Diffraction, Fourier Transform Infrared spectroscopy, Scanning Electron Microscope, and Fluorescence spectroscopy. Thermal stabilities of the phosphors were studied with temperature dependent fluorescence measurements. In addition, density functional theory calc...
Nanoscale Thermal Transport in Single, Bilayer Graphene, and Graphite
Gholivand, Hamed; Donmezer, Nazli (2016-10-12)
In this study, ab-initio calculations were performed to obtain phonon dispersions of single, bilayer graphene, and graphite structures. Using these dispersions single mode relaxation times, thermal conductivities, and mean free paths (MFPs) have been calculated. Finally, calculated variables were used to understand the effects of additional layers to thermophysical properties, phonon mode contributions to thermal conductivity, and the limits for ballistic-diffusive heat transfer of single, bilayer graphene,...
LANTHANUM DOPED DICALCIUM PHOSPHATE MIXED WITH GRAPHENE OXIDE BONE CEMENTS AS A POTENTIAL MATERIAL IN BIOMEDICAL APPLICATIONS
Motameni, Ali; Evis, Zafer; -, -; Department of Engineering Sciences (2021-9-06)
In this thesis, mesoporous particles of β-tricalcium phosphate (βTCP, βCa3(PO4)2) and lanthanum (La) doped βTCP were synthesized by wet precipitation method attached with a microwave refluxing system. Pure dicalcium phosphate (DCP) and La modified dicalcium phosphate (La-DCP) bone cements were prepared based on acid/base reaction between βTCP (or La- βTCP) and monocalcium phosphate monohydrate (MCPM) in the presence of water. DCP bone cements were also mixed with 1.5-3.5wt.% of graphene oxide (GO). The obta...
Polyaniline: synthesis characterization solution properties and composites
Yılmaz, Faris; Küçükyavuz, Zuhal; Department of Polymer Science and Technology (2007)
Polyaniline was chemically synthesized at three different temperatures of 25, 0, and -25oC, by oxidative polymerization with ammonium peroxidisulfate at equimolar of aniline to oxidant ratio and 1M HCl. The resulted polyaniline was in a powder form which was characterized by several techniques such as: electrical conductivity, elemental analysis, thermal analysis, wide-angle X-Ray diffraction, and scanning electron microscope. The solution properties of the reduced polymer were studied by viscometry, static...
Energy transfer and stimulated emission dynamics at 1.1 mu m in Nd-doped SiNx
Li, Rui; Yerci, Selçuk; Kucheyev, Sergei O.; van Buuren, Tony; Dal Negro, Luca (2011-03-14)
Neodymium (Nd) doped amorphous silicon nitride films with various Si concentrations (Nd:SiNx) were fabricated by reactive magnetron co-sputtering followed by thermal annealing. The time dynamics of the energy transfer in Nd:SiNx was investigated, a systematic optimization of its 1.1 mu m emission was performed, and the Nd excitation cross section in SiNx was measured. An active Nd:SiNx micro-disk resonator was fabricated and enhanced radiation rate at 1.1 mu m was demonstrated due to stimulated emission at ...
Citation Formats
A. Yılmaz and O. Esentürk, “Tunable optical properties and DFT calculations of RE3+ codoped LaBO3 phosphors,” OPTICAL MATERIALS, pp. 0–0, 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/32616.