Photoluminescent properties of nanostructured Y2O3:Eu3+ powders obtained through aerosol synthesis (original) (raw)
Related papers
2010
Red emitting Y 2 O 3 :Eu 3+ (5 and 10 at.%) submicronic particles were synthesized through ultrasonic spray pyrolysis method from the pure nitrate solutions at 900°C. The employed synthesis conditions (gradual increase of temperature within triple zone reactor and extended residence time) assured formation of spherical, dense, non-agglomerated particles that are nanostructured (crystallite size $20 nm). The asprepared powders were additionally thermally treated at temperatures up to 1200°C. A bcc Ia-3 cubic phase presence and exceptional powder morphological features were maintained with heating and are followed with particle structural changes (crystallite growth up to 130 nm). Emission spectra were studied after excitation with 393 nm wavelength and together with the decay lifetimes for Eu 3+ ion 5 D 0 and 5 D 1 levels revealed the effect of powder nanocrystalline nature on its luminescent properties. The emission spectra showed typical Eu 3+ 5 D 0 ? 7 F i (i = 0, 1, 2, 3, 4) transitions with dominant red emission at 611 nm, while the lifetime measurements revealed the quenching effect with the rise of dopant concentration and its more consistent distribution into host lattice due to the thermal treatment.
Luminescence and crystallinity of flame-made Y 2O 3:Eu 3+ nanoparticles
Advanced Powder Technol, 2007
Cubic and/or monoclinic Y 2 O 3 :Eu 3+ nanoparticles (10-50 nm) were made continuously without post-processing by single-step, flame spray pyrolysis (FSP). These particles were characterized by X-ray diffraction, nitrogen adsorption and transmission electron microscopy. Photoluminescence (PL) emission and time-resolved PL intensity decay were measured from these powders. The influence of particle size on PL was examined by annealing (at 700-1300 • C for 10 h) as-prepared, initially monoclinic Y 2 O 3 :Eu 3+ nanoparticles resulting in larger 0.025-1 μm, cubic Y 2 O 3 :Eu 3+ . The influence of europium (Eu 3+ ) content (1-10 wt%) on sintering dynamics as well as optical properties of the resulting powders was investigated. Longer high-temperature particle residence time during FSP resulted in cubic nanoparticles with lower maximum PL intensity than measured by commercial micron-sized bulk Y 2 O 3 :Eu 3+ phosphor powder. After annealing as-prepared 5 wt% Eu-doped Y 2 O 3 particles at 900, 1100 and 1300 • C for 10 h, the PL intensity increased as particle size increased and finally (at 1300 • C) showed similar PL intensity as that of commercially available, bulk Y 2 O 3 :Eu 3+ (5 μm particle size). Eu doping stabilized the monoclinic Y 2 O 3 and shifted the monoclinic to cubic transition towards higher temperatures.
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%.
Luminescence and crystallinity of flame-made Y2O3:Eu3+ nanoparticles
Advanced Powder Technology, 2007
Cubic and/or monoclinic Y 2 O 3 :Eu 3+ nanoparticles (10-50 nm) were made continuously without post-processing by single-step, flame spray pyrolysis (FSP). These particles were characterized by X-ray diffraction, nitrogen adsorption and transmission electron microscopy. Photoluminescence (PL) emission and time-resolved PL intensity decay were measured from these powders. The influence of particle size on PL was examined by annealing (at 700-1300 • C for 10 h) as-prepared, initially monoclinic Y 2 O 3 :Eu 3+ nanoparticles resulting in larger 0.025-1 μm, cubic Y 2 O 3 :Eu 3+ . The influence of europium (Eu 3+ ) content (1-10 wt%) on sintering dynamics as well as optical properties of the resulting powders was investigated. Longer high-temperature particle residence time during FSP resulted in cubic nanoparticles with lower maximum PL intensity than measured by commercial micron-sized bulk Y 2 O 3 :Eu 3+ phosphor powder. After annealing as-prepared 5 wt% Eu-doped Y 2 O 3 particles at 900, 1100 and 1300 • C for 10 h, the PL intensity increased as particle size increased and finally (at 1300 • C) showed similar PL intensity as that of commercially available, bulk Y 2 O 3 :Eu 3+ (5 μm particle size). Eu doping stabilized the monoclinic Y 2 O 3 and shifted the monoclinic to cubic transition towards higher temperatures.
Synthesis and Characterisation of Y2O3: Eu/Ag powders
2020
Luminescent materials have a wide range of applications, such as organic light emitting devices, inorganic light emitting diode devices, displays, bio detections, etc. In this research, we showed the synthesis of Y 2 O 3 (core): Eu (dopant)/Ag (shell) powders through Ultrasonic Spray Pyrolysis in scale up conditions at 800 °C with a flow rate of air and at constant concentration of yttrium nitrate, europium nitrate and silver nitrate according the previously performed experiments. Detailed characterisation was performed on the produced Y 2 O 3 :Eu/Ag powder using STEM, SEM and EDX analysis. Microstructure observation showed that Y 2 O 3 :Eu/Ag powders are spherical, containing 50 % yttrium oxide, 45.2 silver and 0.65 europium.
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.
Cite this article as: V. Lojpur, L. Mancic, P. Vulic, M.D. Dramicanin, M.E. Rabanal, O. Milosevic, Structural, morphological and up-converting luminescence characteristics of nanocrystalline Y 2 O 3 :Yb/Er powders obtained via spray pyrolysis, Ceramics International, http://dx.Abstract: Sub-micronic, spherical Y 2 O 3 :Yb/Er particles comprising clustered nano-units (70 nm)
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.
Journal of Chemical Engineering of Japan, 2006
Submicron-and nanometer-sized red luminescent particles (Y 2 O 3 :Eu 3+ ) were successfully generated by flame spray pyrolysis (FSP) and the effect of the type of the atomizer, i.e., the ultrasonic nebulizer (UN) and the two-fluid nozzle (TFN) sprayer, on the particle characteristics was investigated. The prepared particles were characterized by field emission-scanning electron microscopy (FE-SEM), an X-ray diffractometry (XRD) analysis and spectrophotometry. UN-FSP produced non aggregated particles with a mean diameter of 754 nm and the relative photoluminescence (PL) intensity (ratio of emission intensity of generated particles to that of commercial particles) varied from 0.36 to 1.01. The Y 2 O 3 :Eu 3+ particles generated by TFN-FSP were softly agglomerated with a mean diameter of 24 nm and the relative PL intensity ranged from 0.21 to 0.24. Regardless of the type of the atomizer used, the generated particles were dense and spherical in the cubic phase and highly crystalline. These results show that TFN-FSP is a versatile method of producing Y 2 O 3 :Eu 3+ nanometer-sized particles compared with UN-FSP.