Luminescence Properties Of Eu3 Research Articles

Synthesis and luminescence properties of Eu3+, Dy3+ co-doped Ca3Bi(PO4)3 single-phase phosphor

Synthesis and luminescence properties of Eu3+, Dy3+ co-doped Ca3Bi(PO4)3 single-phase phosphor

Effects of structural phase changes on the luminescence of Eu-doped (1-x)BaTiO3-xCaZrO3

We investigated the structural and luminescent properties of Eu3+-doped (1-x)BaTiO3-xCaZrO3 (BCTZ:Eu). The changes in the structural symmetry of BCTZ:Eu with CaZrO3 substitution and Eu3+ doping was determined using Rietveld refinement of the X-ray diffraction patterns. Under ultraviolet photoexcitation, the specimens exhibited typical red-orange emission peaks resulting from the f–f transitions from Eu3+ ions. The intensities and asymmetry ratios of the emission intensities, as well as Stark splitting of the emission bands from Eu3+ were found to be strongly dependent on the structural phase transformation of BCTZ from tetragonal to rhombohedral. These findings suggest that BCTZ:Eu possesses a great potential for multifunctional devices that have both ferroelectric and luminous properties.

Synthesis, crystal structure and luminescent properties of Eu3+-activated halotungstates applied in W-LEDs

The self-activated and Eu3+ ions activated halotungstates Ca3WO5Cl2 phosphors have been prepared by the facile solid-state reaction. The crystal structure, photoluminescence excitation (PLE) and emission (PL) spectra, temperature-dependent PLE, and decay curves were investigated. When excited by ultraviolet (UV) light, the pure Ca3WO5Cl2 shows blue emission, which can be ascribed to the typical self-activated emission of charge transfer band (CTB) transitions in [WO5Cl]5- groups. As the temperature increases from 10 to 480 K, the PL intensity decreases, and the emission band appears blue shift. The concentration dependent PL spectra of Ca3WO5Cl2:Eu3+ show several characteristic emission peaks of Eu3+ ions in the red emission region around 615 nm together with the host emission band in the blue emission region at around 450 nm. Accordingly, the broadband originates from the CT behavior in [WO5Cl]5- group, while the sharp lines originate from the 5D0-7F2 transitions in Eu3+ ions. The energy transfer process between Eu3+ and WO5Cl was discussed. All results indicate the possibility for UV to blue LED applications with multi-color emissions in a single stable host.

Optical and photostimulated luminescence properties of Eu:BaFBr translucent ceramics synthesized by SPS

Eu:BaFBr translucent ceramics were synthesized by the spark plasma sintering method, and then the crystal structure, optical and photostimulated luminescence (PSL) properties were investigated. The synthesized 0.05–0.5% Eu:BaFBr are translucent, and the optical transmittance is 30–50%. The photoluminescence and PSL spectra consist of an emission band peaking around 390 nm due to the presence of Eu2+ ion. The photoluminescence quantum yield and the sensitivity of PSL to X-rays are the highest when the doping concentration is 0.5%, and they are higher than those of the commercial Eu:BaFBr imaging plate (IP). In addition, the spatial resolution of an X-ray image obtained by using the 0.5% Eu:BaFBr translucent ceramic as an imaging plate is higher than the one obtained by using the commercial IP.

Preparation, crystal structure, and luminescent properties of CAPh containing lanthanide(III) complexes with various amounts of coordinated solvent molecules

A series of mixed–ligand lanthanide complexes, Ln(Pip)3( iPrOH) x (x = 2 for Ln(III) = La, Ce–Nd, Sm–Eu and x = 1 for Ln(III) = Gd–Lu; HPip is 2,2,2-trichloro-N-(dipiperidin-1-yl-phosphoryl)acetamide, the carbacylamidophosphate (CAPh) ligand), has been synthesized and identified. Using indirect techniques (FT-IR, 1H, 31P-NMR, and absorption spectroscopy) and the X-ray diffraction method (for europium complex) it was found that three Pip -ligands are coordinated to lanthanide(III) ions in a bidentate chelate manner via oxygen atoms of the carbonyl and phosphoryl groups. The oxygen atoms of 2-propanol molecules complete the coordination number of Ln(III) ions to eight (for Ln from La to Eu) or seven (for Ln from Gd to Lu). The europium complex Eu(Pip)3( iPrOH)2 crystallizes in the Рī space group. The {EuO8} polyhedron has a triangular dodecahedron (TDD-8) conformation and exists in a form of a t1t2p2+MC isomer. The luminescent properties of Eu(Pip)3( iPrOH)2 polycrystalline samples were investigated at 300, 77, and 4.2 K.

Study on the luminescent properties of Eu3+-doped TeO2-GeO2-BaO scintillation glasses

Scintillation glasses for hadron calorimeter need high density and excellent luminescent properties. Eu3+-doped TeO2-GeO2-BaO scintillation glasses with the nominal composition of xTeO2-(60-x)GeO2-39BaO-1Eu2O3 (x = 20, 25, 30, 35, 40, 45, and 50) were prepared by melt-quenching method. The structural information induced by various TeO2/GeO2 ratios were discussed by means of density, FTIR spectra and transmittance spectra, together with the asymmetric ratios of Eu3+ ions and Judd-Ofelt analysis. The luminescent properties of Eu3+-doped TeO2-GeO2-BaO scintillation glasses are described byphotoluminescence (PL) and X-ray excited luminescence (XEL) spectra. The results suggest that both PL and XEL intensity of Eu3+-doped TeO2-GeO2-BaO scintillation glasses are observed to drops clearly with an increase in x values, whereas the glass density shows a slight increase. Therefore, a balance should be search for the possible scintillation application between the luminescent efficiency and the strict density requirement.

Influence of rare earth ions on luminescent properties of self-emitting KCa2Mg2(VO4)3 phosphors for lighting application

The influence of rare earth (RE) ions on the photoluminescence (PL) properties of self-emitting KCa2Mg2(VO4)3 phosphors were studied in detail. In this investigation, RE doped and undoped KCa2Mg2(VO4)3 phosphors have been successfully synthesized by solid-state reaction (SSR) method. The phase purity, structural, vibrational and luminescence properties have been investigated by different techniques. KCa2Mg2(VO4)3 phosphor shows self-luminescence properties, it exhibits broad emission in the range of 400–650 nm under 346 nm excitation. Interestingly, with the doping of Dy3+ ions in KCa2Mg2(VO4)3, we have noted that emission intensity increases in the initial stage up to 0.3 mol% concentration of Dy3+ ions, after that concentration quenching observed. In addition, luminescence properties of Eu3+ doped KCa2Mg2(VO4)3 phosphors were also investigated for multiple excitation wavelengths. They shows energy transfer behaviour between VO43– and Eu3+. The Commission Internationale de l′Elcairage (CIE) coordinates of RE doped and undoped KCa2Mg2(VO4)3 phosphors have been calculated using OSRAM SYLVANIA color calculator. Overall investigations and their outcomes, it was clearly proved that prepared phosphors have huge potential for future generation lighting technology.

Partially Ordered Lanthanide Carboxylates with a Highly Adaptable 1D Polymeric Structure.

A new family of 14 isostructural [Ln(piv)3(en)]∞ lanthanide pivalate (piv−, 2,2-dimethylpropanoate) complexes with ethylenediamine (en) was synthesized by a topology-preserving transformation from 1D coordination polymers [Ln(piv)3]∞. The crystal structures of the compounds were determined by single-crystal and powder X-ray diffraction, which demonstrated that despite the regular ligand arrangement within the chains, the latter are intricately packed within the partially ordered crystal, as only two of four ligands are strictly bound by the translational symmetry. The peculiarities of the lanthanide coordination environment were explored by total X-ray scattering with pair distribution function analysis. Periodic DFT calculations revealed the chain stabilization by intrachain H-bonds and weak interchain interactions. Noticeably, the energy difference was infinitesimally small even between the two considered extreme variants of ordered packing, which is in line with the disturbed packing order of the chains. The luminescent properties of Eu and Tb complexes were investigated in order to prove the energy transfer between lanthanide ions within the heterometallic complex. This opens up the prospect of creating new materials for optical applications. The heterometallic compound Eu0.05Tb0.95(piv)3(en) was synthesized, and was found to demonstrate temperature-dependent luminescence with a linear dependence of the thermometric parameter I(Eu)/I(Tb) within the temperature range from −80 °C to 80 °C, and had a maximum relative sensitivity value of 0.2%/K.

Synthesis and Luminescence Properties of Eu2+-Doped Sr3MgSi2O8 Blue Light-Emitting Phosphor for Application in Near-Ultraviolet Excitable White Light-Emitting Diodes.

In this study, [Sr0.99Eu0.01]3MgSi2O8 phosphors were sintered at 1200–1400 °C for 1–5 h by using the solid-state reaction method. The crystallinity and morphology of these phosphors were characterized through X-ray diffraction analysis and field-emission scanning electron microscopy, respectively, to determine their luminescence. The photoluminescence properties, including the excitation and emission properties, of the prepared phosphors were investigated through fluorescence spectrophotometry. The α-Sr2SiO4, Sr2MgSi2O7, and Sr3MgSi2O8 phases coexisted in the [Sr0.99Eu0.01]3MgSi2O8 phosphors, which were synthesized at low temperatures. The particles of these phosphors had many fine hairs on their surface and resembled Clavularia viridis, which is a coral species. Transmission electron microscopy and energy dispersive X-ray spectroscopy indicated that the fine hairs contained the Sr2SiO4 and Sr2MgSi2O7 phases. However, when the [Sr0.99Eu0.01]3MgSi2O8 phosphors were sintered at 1400 °C, the Sr3MgSi2O8 phase was observed, and the Eu2+-doped Sr3MgSi2O8 phase dominated the only broad emission band, which had a central wavelength of 457 nm (blue light). The emission peaks at this wavelength were attributed to the 4f65d1–4f7 transition at the Sr2+(I) site, where Sr2+ was substituted by Eu2+. The average decay time of the synthesized phosphors was calculated to be 1.197 ms. The aforementioned results indicate that [Sr0.99Eu0.01]3MgSi2O8 can be used as a blue-emitting phosphor in ultraviolet-excited white light-emitting diodes.

Self-Reduction Mechanism and Luminescence Properties of Eu2+-Eu3+Doped Ca(PO3)2 Phosphor

A series of Ca(PO3)2 phosphors mono-doped with Eu3+ were successfully synthesized by the conventional high-temperature solid-phase method. Rietveld correction of the X-ray diffraction shows that Eu3+ ions occupy Ca2+ positions in the Ca(PO3)2 lattice and have no effect on the matrix structure. In this work, the self-reduction of Eu3+ was observed and verified by photoluminescence (PL), excitation spectroscopy (PLE) and X-ray photoelectron spectroscopy (XPS). Under excitation at 238 nm, Ca(PO3)2: Eu exhibits a broad blue Eu2+ emission band in addition to the usual orange-red emission of Eu3+. The fact that europium ions exist in divalent and trivalent forms was further confirmed, and the corresponding mechanism of the anomalous reduction of Eu3+ to Eu2+ is discussed. On this basis, the effect of Eu concentration on the structure and luminescence properties of Ca(PO3)2 phosphor was investigated in detail. The luminescence of the phosphor exhibited bright tunable emission in the blue region and the red region. These results indicate that the Ca(PO3)2: Eu phosphors have potential applications as a n-UV convertible phosphor for light-emitting diodes.

Microstructure and Luminescence Properties of Eu3+ Doped Tungsten Trioxide Nanoparticles Prepared by Hydrothermal Method

Microstructure and Luminescence Properties of Eu3+ Doped Tungsten Trioxide Nanoparticles Prepared by Hydrothermal Method

Structure and luminescent properties of Eu3+-doped phosphate glass for display device applications

Structure and luminescent properties of Eu3+-doped phosphate glass for display device applications

Luminescent properties of Eu3+-doped NaLaCaWO6 red phosphors and temperature sensing derived from the excited state of charge transfer band

In this study, a series of NaLaCaWO6: Eu3+ phosphors were synthesized by traditional high-temperature solid-phase method. The doping concentration of Eu3+ was explored when the phosphors had the best luminescence performance, and the quenching concentration of Eu3+ could reach 30%. The mechanism of concentration quenching is due to electric dipole-electric dipole interaction. The CIE coordinates of the phosphor are (0.66, 0.34), which are close to the standard red region of National Television Standard Committee (NTSC). Therefore, the samples could be potentially used as red phosphors of white light emitting diodes. The optical thermometry properties of NaLaCaWO6:30%Eu3+ phosphors in 298–523 K were studied through temperature-dependent excitation spectra. The results demonstrate negative thermal quenching at the edge of the charge transfer band (CTB) with a red shift of the center of this band as temperature arises. Derived from the excited state of CTB, an optical temperature sensing strategy is proposed, and the relative sensitivity achieves 2.23%/K−1.

Characterization and luminescence properties of Eu3+ doped BaCO3 nanoparticles synthesized by autocombustion method

Nanostructured powders of undoped and europium (Eu3+) doped barium carbonate (BaCO3) were prepared by the autocombustion method. We investigated the influence of Eu3+ doping on the optical properties of barium carbonate. The samples nanostructures were characterized by X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential thermal analysis (DTA) and photoluminescence (PL). The results obtained by XRD revealed that the samples consist of the BaCO3 phase with orthorhombic structure having the space group Pmcn, retaining this crystalline phase after doping with Eu3+. These products were found for undoped and BaCO3: Eu3+ nanoparticles with 56–71 nm and 49–60 nm ranges, respectively. SEM reveals that the barium carbonate nanoparticles had a spherical morphology. Symmetric stretches, asymmetric stretches, and in plane bending vibrations, and out of plane of CO32− complexes have detected. The photoluminescence of the obtained BaCO3:Eu3+ were studied. The CIE co-ordinates for the Eu3+ doped BaCO3 were x = 0.580 and y = 0.330. From the CIE chromaticity diagram for the emissions of Eu3+ doped BaCO3. The material has such color purity and reaches 76%. Thus, having color tenability and has been considerate as a candidate of the laser emission.

Metastable polymorphs and luminescence of boehmite-derived alumina doped with divalent europium ions

The control of polymorphism transition of Eu[Formula: see text] ion-doped [Formula: see text]-, [Formula: see text]-, [Formula: see text]- and [Formula: see text]-metastable alumina derived from boehmite is demonstrated by the sol–gel method through controlling the doping amount and firing temperature and the resultant luminescent properties are investigated. Nanosized boehmite ([Formula: see text]-AlOOH) particulates in boehmite sol effectively prevent the formation of impurity phases of EuAlO2 and Eu2O3. The polymorphic structures of the induction-fired xerogel samples in weak reductive atmosphere can be held to the room temperature upon cooling down naturally. The luminescence properties of Eu[Formula: see text] ions verify the polymorphic transitions from [Formula: see text]-, [Formula: see text]-, [Formula: see text]- to [Formula: see text]-Al2O3 that are featured with their broad emission peaks positions at 410, 450, 480 and 500 nm, respectively. It is believed that boehmite sol–gel by taking the nanosized [Formula: see text]-AlOOH particulates as seeds assisted the dispersion of precursor constituents and is effective to adjust the onset of polymorphic transition temperatures and luminescence properties.

Synthesis and luminescent properties of Eu3+ organic complex PVA encapsulation film

A complex with Eu[Formula: see text] as the luminescent center, 2-thiophenecarbonyl trifluoroacetone (TTA) as the first ligand and o-phenanthroline (Phen) as the co-ligand was designed and synthesized. The complex was then dispersed into polyvinyl alcohol (PVA) to form the Eu[Formula: see text]Tb[Formula: see text](TTA)3phen/PVA composite. The structure and reaction processes of the composites were analyzed by FE-SEM and XRD, and the optical properties of Eu[Formula: see text]Tb[Formula: see text](TTA)3phen complexes with different contents were analyzed by fluorescence spectroscopy.

Effects of doping content and crystallite size on luminescence properties of Eu3+ doped fluorapatites obtained from natural waste

In this study, Eu 3+ doped natural fluorapatites [Ca 10 (PO 4 ) 6 F 2 :xEu 3+ (x = 0.1, 0.3 and 0.5)] were produced from a natural waste by solid-state powder synthesis, conventional sintering, and spark plasma sintering techniques. The effects of doping content and crystallite size on luminescence properties of fluorapatite were investigated by XRD, SEM, and PL analysis. The obtained results showed that luminescence emission's intensity significantly increased with doping content, but no effect was observed on the density and crystallite size. For the samples produced with different methods, emission intensity was the lowest for sintered samples by SPS (1150 °C, 10 min, 50 MPa) with the smallest crystalline size. In contrast, emission intensity was found much higher for synthesized powders with the largest crystallite size. Furthermore, upon excitation under UV radiation, the Eu doped fluorapatites demonstrated the characteristic 5 D 0 – 7 F 2 and 5 D 0 – 7 F 4 emission lines of Eu 3+ at 618 nm and 704 nm (red region) with an ultrahigh intensity that has been firstly observed in the literature. Therefore, Eu doped fluorapatites, quickly produced from a natural waste in an eco-friendly and cost-effective way, carry a potential to be used in biological applications and lightning applications.

Luminescence properties of Eu2+ and Sm3+ co-doped in KBaPO4

Abstract KBaPO4:Eu2+/Sm3+ phosphor was synthesized via the high-temperature solid-phase reaction method. The structural properties, surface morphology, and optical properties of the synthesized samples were obtained by the X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and fluorescence measurements. The XRD patterns indicate that the crystal structure of KBaPO4 has not been changed by co-doped with two rare-earth ions. Under the excitation of 400 nm, the Eu2+ and Sm3+ co-doped KBaPO4 phosphors showed typical emission peaks at 430 (blue), 562 (yellow), and 600 nm (red). Meanwhile, with the increase of the Sm3+ content, the photoluminescent (PL) emission intensity of Sm3+ increased until the content reaches 0.12. However, the PL intensity of Eu2+ ions gradually decreased, which indicated that there was a possible energy transfer between the two ions. Therefore, the obtained results indicated that Eu2+/Sm3+ co-doped KBaPO4 is a promising phosphor for the use in white light-emitting diodes with near ultraviolet chips.

Structural, photoluminescence and Judd-Ofelt analysis of red-emitting Eu3+ doped strontium hexa-aluminate nanophosphors for lighting application

In this paper, the structural and luminescence properties of Eu 3+ - doped SrAl 12 O 19 nanophosphors are discussed. A series of SrAl 12 O 19 :xEu 3+ (x = 0.5, 1, 1.5, 2 and 2.5 mol %) nanophosphors were prepared using urea assisted-combustion synthesis method. The elemental and phase identification were performed by X-ray diffraction. The peak positions in the X-ray diffraction pattern have confirmed the formation of hexagonal structure. The vibration of oxide bonds and the formation of the molecules were confirmed from FTIR spectra. The surface morphology and particle size distribution are estimated using Field Emission-Scanning Electron Microscopy (FE-SEM), High Resolution-Transmission Electron Microscopy (HR-TEM). The optical properties of prepared nanophosphors series are studied using photoluminescence spectra and UV–visible spectra analysis. The refractive index of the optimized concentration of nanophosphor is estimated using Herve and Vandamme relation. Further, Judd-Ofelt analysis was performed on photoluminescence emission spectra. The potential application of synthesized nanophosphors in light-emitting devices (LED) is verified using photometry analysis on obtained emission spectra. The obtained CCT number confirmed that these phosphors are useful as a red color LED. • Red-emitting Eu 3+ -doped strontium hexa-aluminate nanophosphors are synthesized using combustion synthesis method. • The luminescence intensities of nanophosphors are strongly depending on Eu 3+ -concentration. • A detail Jud-Oflet analysis is performed on the nanophosphors. • The estimated CCT values showed that these phosphors are used for warm lighting application.

The effect of two-way energy-transfer on the luminescence properties of Eu3+/Ho3+ codoped 60TeO2:40ZnO glass

Optical emission and energy-transfer Eu3+↔Ho3+ process is investigated in Eu3+/Ho3+-codoped 60TeO2:40ZnO glass. Absorption and excitation spectra were collected, and photoluminescence was investigated as a function of concentration using excitations at 394 and 438 ​nm. The emissions were sensitive to the excitation wavelength, which determined the donor/acceptor role in the energy transfer mechanism. Two-way Eu3+↔Ho3+ energy-transfer was observed in the same host, with the Ho3+→Eu3+ route being the most efficient. This result may impact future studies exploring the properties of Eu3+/Ho3+-based phosphors.