Effect of Different Additives on the Size Control and Emission Properties of Y2O3:Eu3+ Nanoparticles Prepared through the Coprecipitation Method (original) (raw)
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Nanoparticles of europium-doped yttrium oxide (Y 2 O 3 :Eu 3+ ) were synthesized by coprecipitation method with use of different surfactants like butanol, hexanol, and oleic acid. The as-prepared Y 2 O 3 :Eu 3+ samples were annealed at 800°C and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and UV-visible and photoluminescence (PL) spectroscopy techniques. The nanoparticle shows cubic phase structure. Surfactant helps to inhibit or control the particle growth and avoids agglomeration of nanoparticles effectively by reducing the oxygen bridge bonds between the particles. The most intense red emission peak occurs at 614 nm at an excitation wavelength of λ ) 200 nm. Nanoparticles of Y 2 O 3 :Eu 3+ with a particle size of 30 nm synthesized by using oleic acid with NaCl show a 73% rise in PL intensity of the 614 nm peak.
Morphology controlled Y2O3:Eu3+ nanophosphors with enhanced photoluminescence properties
Journal of Luminescence, 2015
Eu 3 þ doped Y 2 O 3 is prepared by a co-precipitation method using ammonium hydrogen carbonate as precipitating agent. In the present work we studied the effect of different molar concentrations of Poly vinyl pyrrolidone (PVP) and 1-Thio-glycerol (TG) as capping agents to enhance the optical and morphological properties of Y 2 O 3 :Eu 3 þ nanophosphors. In addition, variation of pH was studied to control the particle size of the synthesized product. The polymer concentration (TG and PVP) was also optimized at different pH to get higher luminescence of Eu 3 þ doped Y 2 O 3 nanoparticles (NPs). It was observed that pH of solution during synthesis and also its concentration affect the morphological and optical properties of Y 2 O 3 :Eu 3 þ . The structural, morphological and optical properties were studied by an X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy and photoluminescence spectroscopy. XRD studies followed by Rietveld refinement confirmed the bodycentered cubic structure of doped nanophosphors. It was observed that at optimized pH and polymer concentration the nanoparticles of Y 2 O 3 :Eu 3 þ have narrow size distribution and exhibited enhanced photoluminescent properties.
Optical Materials, 2014
Nano-sized yttria (Y 2 O 3 ) doped with Eu 3+ powders were successfully synthesized by co-precipitation method, where the quenching concentration for photoluminescence study of Eu 3+ ions is 12 mol% which is much higher than the micro-scaled powders. The effect of changing concentration of co-dopants (Li + , Na + and K + ) along with Eu 3+ (12 mol%) is studied on optical properties of Y 2 O 3 nanoparticles. The results showed that the incorporation of these metal ions can further improve the luminescence intensity. The highest emission intensity was observed with 6 mol% of Li + , 2 mol% of Na + , and 1 mol% of K + doping in Y 2 O 3 :Eu 3+ (12 mol%) nanoparticles given by the formula (Y 0.82mol% Eu 0.12mol% Li 0.06mol% ) 2 O 3 , (Y 0.86mol%-Eu 0.12mol% Na 0.02mol% ) 2 O 3 , and (Y 0.87mol% Eu 0.12mol% K 0.01mol% ) 2 O 3 respectively. The structural, morphological and optical properties were studied by X-ray diffraction, Rietveld refinement, transmission electron microscopy, Fourier transform infrared spectroscopy, and Photoluminescence spectroscopy. XRD studies followed by Rietveld refinement confirmed the body-centered cubic structure of doped nanophosphors. All the powders were well crystallized and the emission intensity was observed to increase further from quenching concentration of Eu 12 mol% with co-doped samples.
Photoluminescence Efficiencies of Nanocrystalline versus Bulk Y2O3:Eu Phosphor—Revisited
Highly efficient yttrium oxide doped with trivalent europium (Y 2 O 3 :Eu) phosphor was prepared through precursors synthesized by hydrothermal method. Crystalline precursors, namely europium-doped yttrium carbonate (Y 2 (CO 3 ) 3 . 2H 2 O:Eu) and europium-doped yttrium hydroxy carbonate (Y(OH)CO 3 :Eu), were prepared by varying the concentration of yttrium to europium ions and urea in the reaction mixture. The precursor materials on annealing at 7001C gave nanocrystalline Y 2 O 3 :Eu, which was further processed at high temperatures in the absence and presence of sintering aid to yield phosphor materials with varying crystallite size and morphology. The precursors and phosphor material were characterized using FTIR, TGA, powder XRD, SEM, TEM, and photoluminescence (PL) spectral studies. The emission efficiency was found to depend on the crystallite size, morphology, and particle size of the phosphor materials. It was observed that phosphor material with spherical morphology and particle size of 0.5-1.0 lm with crystallite size of 100 nm has the highest PL efficiency.
Spherical-shaped Y2O3:Eu3+ nanoparticles with intense photoluminescence emission
Ceramics International, 2015
Herein we report on the crystallized nanoparticles based on Eu 3 þ -doped Y 2 O 3 with 5 mol% using citric acid as precursor. The heating temperatures were evaluated in order to obtain the best crystallized nanoparticles with size around 12 nm and with highest red intense photoluminescence emission. Nanocrystallite size was calculated by Scherrer's equation based on diffractogram of the material heated at 750 1C for 4 h, obtaining size around 8 nm. The low photoluminescence intense emissions were attributed to the presence of quenchers remaining from precursors used in the synthesis. In general the photoluminescence properties were evaluated based on emission and excitation spectra profile. Rietveld refinement was performed based on the diffractogram of the material annealed at 750 1C for 4 h, and the visualization of the cubic structure was obtained. The centered cubic crystalline structure of Y 2 O 3 was obtained and the photoluminescence properties of Eu 3 þ ion in Y 2 O 3 host lattice was verified as being dependent on the temperature of heating and C 2 and S 6 site of symmetry present in the cubic structure. CIE chromaticity diagram was obtained with x and y being 0.682 and 0.316, respectively, for material with the highest relative photoluminescence intensity.
Luminescence studies of europium doped yttrium oxide nano phosphor
Sensors and Actuators B: Chemical, 2012
Luminescence exhibiting europium doped yttrium oxide (Y 2 O 3 :Eu 3+) phosphor was prepared by solution combustion method, using disodium ethylene diamine tetra acetic acid (EDTA-Na 2) as fuel at ∼350 • C. Powder X-ray diffraction (PXRD) pattern of Y 2 O 3 :Eu 3+ revealed the cubic crystalline phase. The morphology of the samples was studied by scanning electron microscopy (SEM) and was foamy, fluffy and porous in nature. Fourier transformed infrared spectroscopy (FTIR) revealed prominent absorption with peaks at 3415, 1435, 875 and 565 cm −1. Optical absorption studies showed the energy gap of the synthesized samples to be 5.4-5.5 eV. The photoluminescence (PL) of Y 2 O 3 :Eu 3+ exhibiting emission peak at 611 nm under the excitation of 254 nm. Thermoluminescence of ␥-irradiated Y 2 O 3 :Eu 3+ showed two well resolved TL glows with peaks at 460 and 610 K and they were analyzed by glow curve shape method and the activation energies were found to be 0.421 eV and 1.016 eV respectively.
Luminescence : the journal of biological and chemical luminescence, 2015
Europium trivalent (Eu(3+) )-doped Y2 O3 nanopowders of different concentrations (0.5, 2.5, 5 or 7 at.%) were synthesized by the sol-gel method, at different pH values (pH 2, 5 or 8) and annealing temperatures (600°C, 800°C or 1000°C). The nanopowders samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) and steady state photoluminescence spectroscopy. The effect of pH of solution and annealing temperatures on structural, morphological and photoluminescence properties of Eu(3+) -doped Y2 O3 were studied and are discussed. It was found that the average crystallite size of the nanopowders increased with increasing pH and annealing temperature values. The Y2 O3 :Eu(3+) material presented different morphology and its evolution depended on the pH value and the annealing temperature. Activation energies at different pH values were determined and are discussed. Under ultraviolet (UV) ligh...
2015
Y2O3:Eu nanophosphors are prepared from different synthesis viz. Combustion synthesis, Precipitation Method, Sol-Gel. The samples are annealed from 600-14000C temperature. Effect of Temperature on luminescence intensity of Europium Doped Y2O3 phosphor prepared from different synthesisroutes is studied in the presented paper. Prepared samples are found to have monoclinic structure when compared with JCPDS standard data. The luminescence intensity increases with the increase of particle size and is affected by synthesis route. Eu doped Y2O3 particle shows sharp emission at 611nm at UV excitation. The samples are excited with different UV wavelength and maximum emission intensity is found when excited with 234nm wavelength. Powder X-Ray Diffraction (XRD) results indicated that high temperature leads to increase in the particle size. TEM photographs show the agglomeration of the samples at higher temperature.
Journal of Materials Research, 2007
A monodisperse spherical Y2O3:Eu3+ phosphor was prepared by a homogeneous precipitation method. The mean size of the phosphor particles (MSPP) was successfully controlled by changing the volume ratio of normal alcohol (RA) (propanol) in the solvents mixed between deionized water and normal propanol. When the RA was increased from 0 to 0.7, the MSPP decreased while maintaining a high yield of >95%. Although the prepared phosphor samples were fired at the same temperature, the thermal energy was delivered more efficiently into the inner side of the phosphor particles with the decrease of the MSPP. Therefore, the crystallinity and also the photoluminescence (PL) intensity of the phosphor increased with the decrease in the MSPP. In addition, because the numbers of Eu3+ ions located near the particle surfaces increased with the decrease of particle size, the ratio of PL intensity caused by the 5D0–7F2 transition to that caused by 5D0–7F1 transition increased from 10.8 to 12.7 with the...
Luminescent properties of nano-sized Y 2O 3:Eu fabricated by co-precipitation method
Journal of Alloys and Compounds, 2010
Nano-sized yttria (Y 2 O 3 ) powders were successfully synthesized by co-precipitation method. The structure and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). All the powders were well crystallized and the grains were almost spherical with good dispersibility. The relationship between optical properties and the content of Eu 3+ and Li + ions was studied. The quenching concentration of Eu 3+ ions is 9 mol% which is much higher than the micro-scaled powders. The results also showed that the incorporation of Li + ions can greatly improve the luminescence intensity. The highest emission intensity was observed with 4 mol% Li + doped Y 2 O 3 :Eu powder ((Y 0.87 Eu 0.09 Li 0.04 ) 2 O 3 ) and the fluorescence intensity was increased by as much as 79%.