Photoluminescence and Crystal-Field Analysis of Pr3+-Doped SrMoO4 Phosphors

AbstractThe phosphor SrMoO4:Pr3+ was successfully prepared by high-temperature solid-state reaction process, and characterised by X-ray diffraction (XRD), scanning electron microscope (SEM), and fluorescence spectrometer. The results show that the prepared SrMoO4:Pr3+ has a scheelite structure with pure phase and represents leaf-like shapes with good dispersity. The strong electron absorbabilities are located at 220–300 nm (charge transfer band), 448, 474, and 487 nm, respectively. The emission spectrum of the SrMoO4:Pr3+ phosphor was characterised, which peaked at 529, 545, 554, 600, 619, and 645 nm, corresponding to the f–f transitions of Pr3+. The average International Commission on Illumination (CIE) chromaticity coordinates of the phosphors are x≈0.455, and y≈0.520, and the optimum doping mole fraction of Pr3+ is 0.2 mol.%. To better understand the fluorescent behavior of as-prepared phosphors, a complete 91×91 energy matrix was built by an effective Hamiltonian operator, including free ion and crystal-field interactions. The fluorescent spectra of Pr3+ ion at the tetragonal (S4) Sr2+ site of SrMoO4 crystal were firstly calculated from a full diagonalisation (of energy matrix) method. The fitting values are in good agreement with the experimental data.

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Y2O3:Eu3+ Nanophosphor-Coated Mica or TiO2/Mica as Red-Emitting Pearl Pigment: Coating Factors, Luminescent and Gloss Properties

Applied Sciences ◽

10.3390/app11104365 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4365

Author(s):

Se-Min Ban ◽

Mahboob Ullah ◽

Kyeong Youl Jung ◽

Byung-Ki Choi ◽

Kwang-Jung Kang ◽

...

Keyword(s):

Electrostatic Interaction ◽

X Ray Diffraction ◽

X Ray ◽

Wet Process ◽

Red Color ◽

Chromaticity Coordinates ◽

Bead Mill ◽

Coating Method ◽

Cie Chromaticity ◽

Fluorescence Spectrometer

Red-emitted Y2O3:Eu3+ nanophosphor coated on a mica flake (Y2O3:Eu@MF) or on TiO2 having a rutile crystalline mica flake (Y2O3:Eu@TMF) has been prepared by an electrostatic interaction with the wet-coating method for the purpose of a pigment with luminescent and gloss properties. Aggregated Y2O3:Eu3+, prepared by the template method, was dispersed into nanosol by a controlled bead-mill wet process. The (+) charged Y2O3:Eu3+ nanosol was effectively coated on the (-) charged mica flake (MF) or the TiO2/mica flake (TMF) by an electrostatic interaction between the Y2O3:Eu3+ nanoparticles and MF or TMF at pH 6–8. The coating factors of Y2O3:Eu@MF were also studied and optimized by controlling the pH, stirring temperature, calcination temperature, and coating amount of Y2O3:Eu3+. The Y2O3:Eu3+ was partially coated and optimized on the MF or TMF surface with a coating coverage of about 40–50% or 60–70%, respectively. Y2O3:Eu@MF and Y2O3:Eu@TMF were exhibiting the luminescent property of a red color under a 254 nm wavelength, and had a color purity of over 95% according to CIE chromaticity coordinates. These materials were characterized by X-ray diffraction, FE-SEM, zeta potential, and a fluorescence spectrometer. These materials with luminescent and gloss properties prepared in this work potentially meet their applications for security purposes.

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Synthesis and Luminescence Properties of a Blue-Emitting Sr3NaLu(PO4)3F:Eu2+ Phosphor

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.727.623 ◽

2017 ◽

Vol 727 ◽

pp. 623-627 ◽

Cited By ~ 1

Author(s):

Zai Fa Yang ◽

Deng Hui Xu ◽

Xue Dong Gao ◽

Jiang Nan Du ◽

Jia Yue Sun

Keyword(s):

Blue Emission ◽

Fluorescence Decay ◽

Ultraviolet Region ◽

X Ray Diffraction ◽

Blue Emission Band ◽

Light Emitting ◽

Near Ultraviolet ◽

Chromaticity Coordinates ◽

Cie Chromaticity ◽

White Light Emitting Diodes

A novel blue-emitting Sr3NaLu (PO4)3F:Eu2+ phosphor for white light-emitting diodes (w-LEDs) have been successfully prepared via the solid-state reaction. The crystal structure and phase of the prepared phosphors were investigated using X-ray diffraction (XRD). The band gap of Sr3NaLu (PO4)3F was estimated to be about 5.79 eV from the diffuse reflection spectrum. The Sr3NaLu (PO4)3F:0.05Eu2+ phosphor exhibits an intense and broad excitation band ranging from 200 to 450 nm in the near ultraviolet region and produces a bright blue emission band with the CIE chromaticity coordinates of x = 0.133 and y = 0.148 under the excitation of 365 nm, which were ascribed to the 4f-5d transitions of Eu2+. Moreover, the fluorescence decay curves were also investigated in detail. All the results suggest that Sr3NaLu (PO4)3F:Eu2+ might be a promising blue-emitting phosphor used in w-LEDs.

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Comparative study of crystal field analysis in Pr3+ and Yb3+-doped K2LaX5 (X=Cl−, Br−) ternary halides and Yb3+-doped A3Lu(PO4)2 (A=Na+, Rb+) double phosphates. Charge transfer band observations of Yb3+-doped systems

Optical Materials ◽

10.1016/j.optmat.2007.11.005 ◽

2008 ◽

Vol 30 (11) ◽

pp. 1655-1666 ◽

Cited By ~ 22

Author(s):

J. Legendziewicz ◽

J. Cybińska ◽

M. Guzik ◽

G. Boulon ◽

G. Meyer

Keyword(s):

Charge Transfer ◽

Comparative Study ◽

Crystal Field ◽

Charge Transfer Band ◽

Field Analysis

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Novel red-emitting Lu3Te2Li3O12: Eu3+ phosphor with high color purity for n-UV WLEDs

E3S Web of Conferences ◽

10.1051/e3sconf/202018504044 ◽

2020 ◽

Vol 185 ◽

pp. 04044

Author(s):

Mingyang Qu ◽

Xiyan Zhang ◽

Xiaoyun Mi ◽

Quansheng Liu ◽

Shaoqiu Xu

Keyword(s):

Emission Spectra ◽

Dipole Interaction ◽

X Ray Diffraction ◽

Excitation Spectra ◽

Chromaticity Coordinate ◽

Chromaticity Coordinates ◽

Optimal Doping Concentration ◽

Cie Chromaticity ◽

First Time ◽

High Color Purity

In this work, a series of red emitting Lu3Te2Li3O12: Eu3+ phosphors were synthesized for the first time by high temperature solid state reaction. The structure was characterized by X-ray diffraction. The excitation spectra, emission spectra and CIE chromaticity coordinate were studied. The phosphors show strong red emission at 611 nm due to the 5D0-7F2 transition of Eu3+ ions. The optimal doping concentration of Eu3+ in LTL host is x = 0.5 due to the concentration quenching mechanism of dipole-dipole interaction. The CIE chromaticity coordinates of the LTL: 0.5Eu3++ phosphor is (0.644,0.355), and the purity of the color is up to 93.61%. The phosphor can be considered as a potential red-emitting candidate for near UV WLEDs.

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Synthesis and Characterization of a Novel Sm+3 Activated NaCdVO4 Phosphors for Red Emitting Material

10.21203/rs.3.rs-478437/v1 ◽

2021 ◽

Author(s):

Marwa Enneffati ◽

Mohammed Rasheed ◽

Narjes Aouani ◽

Bassem Louati ◽

Kamel Guidara ◽

...

Keyword(s):

Solid State Reaction Method ◽

Synthesis And Characterization ◽

X Ray Diffraction ◽

X Ray ◽

White Leds ◽

Chromaticity Coordinates ◽

Cie Chromaticity ◽

Simple Solid State Reaction ◽

Reflectance Data

Abstract Sm3+ activated NaCdVO4 phosphors were prepared by the simple solid-state reaction method. X-ray diffraction, dispersive energy (EDS), scanning electron microscope (SEM), infrared as well as photoluminescence (PL) techniques were used to characterize obtained samples. Irregular and non-uniform structures were observed by SEM. EDS spectra confirmed the presence of Na, Cd, V, O and Sm elements in each sample. Uuder 405nm excitation, the NaCd1 − xVO4: xSm (x = 0.01, 0.03 and 0.05) exhibits a bright red emission consisting mainly of four wavelength peaks at 556, 593, 650 and 700 nm. The highest emission intensity was found with a composition of x = 0.05. The analysis of PL spectra suggest that studied samples can be used as a red emitting phosphors candidates for fabrication of white LEDs. The CIE chromaticity coordinates of prepared samples were close to the blue-emitting phosphors for NaCdVO4 and red-emitting ones for NaCd0.99Sm0.01VO4, NaCd0.97Sm0.03VO4, and NaCd0.95Sm0.05VO4. The band gap energies of phosphors were calculated from reflectance data using K-M function.

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Photoluminescence characteristics and energy transfer phenomena in Ce3+-doped YVO4 single crystal

Science and Engineering of Composite Materials ◽

10.1515/secm-2021-0019 ◽

2021 ◽

Vol 28 (1) ◽

pp. 205-214

Author(s):

Shuai Wang ◽

Pengfei Wang ◽

Yongfeng Ruan ◽

Youfa Wang ◽

Shouchao Zhang

Keyword(s):

Energy Transfer ◽

Single Crystals ◽

Emission Spectra ◽

Czochralski Method ◽

Color Temperature ◽

X Ray Diffraction ◽

Excitation Spectra ◽

Chromaticity Coordinates ◽

Diffraction Patterns ◽

Cie Chromaticity

Abstract The undoped YVO4 and Ce3+-doped YVO4 single crystals have been successfully grown by the Czochralski method in a medium frequency induction furnace. The X-ray diffraction patterns testified that all samples exhibited the pure tetragonal YVO4 crystalline phase without any parasitic phases. The optical properties of Ce3+-doped YVO4 single crystals with different doping concentrations were investigated via a combination of absorption, emission, and excitation spectra. Dependence of luminescence and absorption intensity on Ce3+ doping concentration was discussed at different excitation wavelengths. The typical transitions of Ce3+ ions and the unusual intrinsic luminescent phenomena of VO 4 3 − {\text{VO}}_{4}^{3-} groups were observed and investigated in Ce3+-doped YVO4 crystals. More attentions were paid to ascertaining the corresponding transition states, analyzing luminescent mechanism, and revealing the energy transfer from VO 4 3 − {\text{VO}}_{4}^{3-} to Ce3+ ions. In addition, the CIE chromaticity coordinates and correlated color temperature were calculated on a basis of emission spectra under different excitation wavelengths.

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