Cation substitution induced novel gehlenite Ca2GaAlSiO7:Eu2+/Ce3+phosphor with green/blue emission for UV-WLEDs

Langbeinite-type compounds are a large family that include phosphates, sulfates and arsenates, and which are accompanied by interesting physical properties. This work reports a new disordered langbeinite-type compound, K2GdHf(PO4)3 [dipotassium gadolinium hafnium tris(phosphate)], and its structure as determined by single-crystal X-ray diffraction. Theoretical studies reveal that K2GdHf(PO4)3 is an insulator with a direct band gap of 4.600 eV and that the optical transition originates from the O-2p→Hf-5d transition. A Ce3+-doped phosphor, K2Gd0.99Ce0.01Hf(PO4)3, was prepared and its luminescence properties studied. With 324 nm light excitation, a blue emission band was observed due to the 5d 1→4f 1 transition of Ce3+. The average luminescence lifetime was calculated to be 5.437 µs and the CIE chromaticity coordinates were (0.162, 0.035). One may expect that K2Gd0.99Ce0.01Hf(PO4)3 can be used as a good blue phosphor for three-colour white-light-emitting diodes (WLEDs).

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Structure and luminescence properties of Ce 3+ doped KBa 1 − x (Mg/Zn) x Y(BO 3 ) 2 and K 1 − y Na y BaY(BO 3 ) 2 phosphors evolved from cation substitution

Optics & Laser Technology ◽

10.1016/j.optlastec.2017.01.027 ◽

2017 ◽

Vol 93 ◽

pp. 41-48 ◽

Cited By ~ 2

Author(s):

Rui Xu ◽

Yujun Liang ◽

Shiqi Liu ◽

Yingli Zhu ◽

Xingya Wu ◽

...

Keyword(s):

Luminescence Properties ◽

Cation Substitution

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Synthesis and Luminescence Properties of La2O2S:RE3+ (RE3+ = Ce3+, Dy3+, Eu3+ and Tb3+) Submicron Size Phosphors for Lamp Industry

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.d1657.019420 ◽

2020 ◽

Vol 9 (4) ◽

pp. 1898-1907

Keyword(s):

Solid State ◽

Broad Band ◽

Blue Emission ◽

Luminescence Properties ◽

Excitation Spectra ◽

Yellow Band ◽

Broad Band Emission ◽

Band Emission ◽

Ft Ir ◽

Down Conversion

RE3+(RE3+ = Ce3+, Dy3+, Eu3+ and Tb3+) doped La2O2S phosphors was synthesized by solid state flux fusion method and their down conversion spectral properties were studied as a function different RE3+ concentrations and reported in this paper. The solid state flux fusion results in well crystallized hexagonal shaped phosphor particles. The samples were characterized by XRD, SEM, FT-IR photoluminescence (PL) and CIE colour co-ordinates techniques. The lanthanum oxysulphide (La2O2S) phosphor doped with Ce3+ shows broad band emission with peak at 390 nm and 415 nm when excited at 340 nm excitation. La2O2S:Dy3+ shows efficient blue and yellow band emissions at 480 nm and 572 nm. La2O2S:Eu3+ phosphor shows an orange and red emission at 590 nm and 615 nm. Whereas La2O2S:Tb3+ phosphor shows weak blue emission at 488 nm and strong green 545 nm. The excitation spectra used for the La2O2S:RE3+ (where RE3+ = Ce3+, Dy3+, Eu3+ and Tb3+) phosphors is in the near UV region extending from 350 to 400 nm, which is characteristics of near UV excited LED. The effect of the RE3+ (RE3+= Ce3+, Dy3+ , Eu3+ and Tb3+) concentration on the luminescence properties of La2O2S:RE3+ phosphors were also studied. The investigated prepared La2O2S phosphors may be suitable for a near UV excited W-LED. Keywords: Oxysulphide, SEM, FT-IR, PL, SSL, CIE.

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2,7-Carbazole Derived Organoboron Compounds: Synthesis and Molecular Fluorescence

Frontiers in Chemistry ◽

10.3389/fchem.2021.754298 ◽

2021 ◽

Vol 9 ◽

Author(s):

Minhui Chen ◽

Juan Wei ◽

Yufeng Zhang ◽

Lin Wu ◽

Leibo Tan ◽

...

Keyword(s):

Solid State ◽

Electron Donor ◽

Electron Acceptor ◽

Blue Emission ◽

Luminescence Properties ◽

Quantum Yields ◽

Organoboron Compounds ◽

High Quantum ◽

Molecular Fluorescence ◽

State Luminescence

Triarylboranes have drawn much attention in OLEDs owing to their remarkable solid-state luminescence properties. Here two new A-D-A type compounds, 2,7-bis(dimesitylboryl)-N-ethyl-carbazole (BCz) using triarylborane as electron acceptor and carbazole as electron donor while 2,7-bis((4-(dimesitylboryl)phenyl)ethynyl)-9-ethyl-carbazole (BPACz) using phenylacetylene as extra conjugated bridge, have been synthesized and their photoluminescence related properties in various states have been investigated both experimentally and theoretically. Both compounds show blue emission with high quantum yields, being potential candidates for blue OLED materials.

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Cation substitution and luminescence properties of Eu2+/Ga3+-codoped Na2ZrSi2O7

Journal of Physics D Applied Physics ◽

10.1088/1361-6463/abba5c ◽

2020 ◽

Vol 54 (2) ◽

pp. 025103

Author(s):

Huidong Tang ◽

Longzhu Li ◽

Rong Yang ◽

Yuwei Chen ◽

Hyo Jin Seo

Keyword(s):

Luminescence Properties ◽

Cation Substitution

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Preparation and Luminescence Properties of Dy3+ Doped Sr3Lu(PO4)3 as a New Single Phase White Light Emitting Phosphor

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.727.612 ◽

2017 ◽

Vol 727 ◽

pp. 612-617 ◽

Cited By ~ 1

Author(s):

Jiang Nan Du ◽

Deng Hui Xu ◽

Zai Fa Yang ◽

Xue Dong Gao ◽

Jia Yue Sun

Keyword(s):

White Light ◽

Blue Emission ◽

Solid State Reaction Method ◽

Luminescence Properties ◽

Yellow Emission ◽

The Novel ◽

Light Emitting ◽

Chromaticity Coordinate ◽

Uv Excitation ◽

Optimum Doping Concentration

The novel white light emitting phosphors Sr3Lu(1-x)Dyx(PO4)3 (x = 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized via a conventional high-temperature solid-state reaction method at 1250°C. The excitation spectrum indicated that these phosphors had a strong absorption in near UV region in the range from 260 to 460 nm. And under 350 nm excitation, the blue emission at 483nm (4F9/2→6H15/2) and yellow emission at 576 nm (4F9/2→6H13/2) were observed in the phosphors, respectively. We studied the effect of different doping concentrations of Dy3+ activator on the luminescence properties and found that the optimum doping concentration is 6 mol%. According to the Dexter’s theory, this quenching behavior is ascribed to be electric d-d interaction. Furthermore, the chromaticity coordinate (x = 0.28, y = 0.32) of Sr3Lu (PO4)3:0.06Dy3+ phosphor was very close to the “ideal white” (x = 0.33, y = 0.33) in the chromaticity diagram. Our results indicate that the Sr3Lu (PO4)3:Dy3+ phosphor can serve as a promising candidate for single-component white light emitting phosphor under near UV excitation.

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Luminescence properties and first principles calculations of Dy3+ activated Sr3B2O6 phosphors

Functional Materials Letters ◽

10.1142/s1793604715500228 ◽

2015 ◽

Vol 08 (02) ◽

pp. 1550022 ◽

Cited By ~ 7

Author(s):

Lihan Cai ◽

Xiaodan Li ◽

Qijin Cheng ◽

Jianghui Zheng ◽

Baodian Fan ◽

...

Keyword(s):

White Light ◽

Density Functional ◽

Theoretical Calculations ◽

Blue Emission ◽

Concentration Quenching ◽

Solid State Reactions ◽

Luminescence Properties ◽

Yellow Emission ◽

Light Emitting ◽

Cie Chromaticity

A novel white-light-emitting Sr 3 B 2 O 6: Dy 3+ phosphor was prepared by solid-state reactions and its luminescence properties were investigated. The excitation spectrum of obtained phosphor monitored at 479 nm covers a very broad spectral region from 320 nm to 460 nm with peaks at 323, 349, 363, 386, 427 and 456 nm. Under excitation at 349 nm, the phosphor exhibits a blue emission centered at 479 nm and a yellow emission centered at 574 nm. The optimal doping concentration of Dy 3+ is obtained to be 7 mol%, and the concentration quenching is observed when the concentration of Dy 3+ exceeds 7 mol%. This concentration quenching is due to the enhanced energy exchange among Dy 3+ ions. The CIE chromaticity coordinate (0.289, 0.302) of Sr 3-0.07 B 2 O 6:0.07 Dy 3+ located in the white-light region can be achieved. Theoretical calculations of electronic properties for Sr 3 B 2 O 6: Dy 3+ phosphor in the framework of the density functional theory (DFT) were carried out. Our results suggest that the Sr 3 B 2 O 6: Dy 3+ phosphor is a promising single-component white-light-emitting material.

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Luminescence Properties of Silicon Nanocrystals

MRS Proceedings ◽

10.1557/proc-452-141 ◽

1996 ◽

Vol 452 ◽

Cited By ~ 1

Author(s):

Shoutian Li ◽

Stuart J. Silvers ◽

M. Samy El-Shall

Keyword(s):

Quantum Confinement ◽

Blue Emission ◽

Emission Wavelength ◽

Luminescence Properties ◽

Raman Shift ◽

Laser Vaporization ◽

Emission Characteristic ◽

Red Emission ◽

Si Nanocrystals ◽

Si Nanoparticles

AbstractWeblike aggregates of coalesced Si nanocrystals are produced by a laser vaporization -controlled condensation technique. SEM micrographs show particles with ∼ 10 nm diameters but the Raman shift suggests the presence of particles as small as ∼ 4 nm. FTIR of the freshly prepared particles shows weak peaks due to the stretching, bending and rocking vibrations of the Si-O-Si bonds indicating the presence of a surface oxidized layer SiOx (x<2).The particles show luminescence properties that are similar to those of porous Si and Si nanoparticles produced by other techniques. The nanoparticles do not luminesce unless, by exposure to air, they acquire the SiOx passivated coating. They show a short-lived blue emission characteristic of the SiO2 coating and a biexponential longer-lived red emission. The short lifetime component of the red emission, about 12 μs, does not depend on emission wavelength. The longer-lived component has a lifetime that ranges from 90 to over 130 μs (at 300 K), increasing with emission wavelength. The results are consistent with the quantum confinement mechanism as the source of the red photoluminescence.

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Host-sensitized luminescence properties of KLa5O5(VO4)2:Eu3+ for solid-state lighting applications

Journal of Materials Chemistry C ◽

10.1039/c6tc02258h ◽

2016 ◽

Vol 4 (30) ◽

pp. 7277-7285 ◽

Cited By ~ 23

Author(s):

Marie Colmont ◽

Sébastien Saitzek ◽

Arturas Katelnikovas ◽

Houria Kabbour ◽

Jacob Olchowka ◽

...

Keyword(s):

Solid State ◽

Blue Emission ◽

Solid State Synthesis ◽

Solid State Lighting ◽

Luminescence Properties ◽

Sensitized Luminescence ◽

Synthesis Route ◽

Uv Excitation

K1La5−xEuxO5(VO4)2 compounds were prepared by a solid state synthesis route. Their luminescence properties were studied. The non-substituted sample that exhibits blue emission under UV excitation switched to orange/red as soon as a small amount of europium is inserted in the phosphor.

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Analysis of emission of Eu3+ and Dy3+ doped Magnesium Boro-Tellurite (MBT) ceramics

Materials Science-Poland ◽

10.1515/msp-2015-0018 ◽

2015 ◽

Vol 33 (1) ◽

pp. 122-125

Author(s):

Nur Zu Ira Bohari ◽

R. Hussin ◽

Zuhairi Ibrahim ◽

Hendrik O. Lintang

Keyword(s):

Rare Earth ◽

Blue Emission ◽

Emission Spectra ◽

Solid State Reaction Method ◽

Luminescence Properties ◽

Luminescence Spectroscopy ◽

Yellow Emission ◽

X Ray Diffraction ◽

Crystalline Phases ◽

Fluorescent Lamps

AbstractRare earth (RE) ions play an important role in the improvement of the optical properties of ceramics. Rare-earth ceramics are commonly used in display panels, fluorescent lamps and lasers. The luminescence properties of Magnesium Boro-Tellurite (MBT) Eu3+ and Dy3+ doped ceramics have not been reported before. Therefore, the aim of this paper is to determine the effect of different compositions on the luminescence properties of the MBT material. A series of xTeO2-(70-x)B2O3-30MgO ceramics with 10 ≤ x ≤ 40 mol % doped with 1 mol % of Eu3+ and Dy3+ ions was prepared via the solid-state reaction method. The influence of various compositions on the crystalline phase and photoluminescence properties of the samples were investigated by X-ray diffraction (XRD) and luminescence spectroscopy. The crystalline phases obtained in this study are Mg3(BO3)2, MgB4O7, Mg2B2O5, Mg(Te2O5) and MgTe3O6. It was stated that the crystalline phases have not changed as a result of doping with Eu3+ and Dy3+ ions. The emission spectra of Eu3+: MBT ceramics showed strong red emission at 612 nm due to the transition of 5D0 → 7F2 and meanwhile, the Dy3+: MBT ceramics showed a blue emission at 480 nm due to 4F9/2 → 6H15/2 transition and yellow emission at 576 nm due to 4F9/2→6H13/2 transition. Both the rare-earth doped phosphors showed bright emission.

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