Preparation of Y4MgSi3O13:Tb3+,Ce3+ Green Emitting Phosphor for White Light Emitting Diodes and its Luminescence Study

2011 ◽  
Vol 415-417 ◽  
pp. 1333-1339
Author(s):  
Guo Hua Song ◽  
Bin Jiang ◽  
Jian Wen Miao ◽  
Bang Dong Ding
Keyword(s):  
Sol Gel ◽  
Emission Spectra ◽  
Green Emission ◽  
Green Phosphor ◽  
Preparation Temperature ◽  
Light Emitting ◽  
Optimal Doping ◽  
Optimal Doping Concentration ◽  
White Light Emitting Diodes ◽  
Luminescence Characteristics

The Y4MgSi3O13:Tb3+,Ce3+green phosphors are synthesized by sol-gel method, the preparation temperature, reduction atmosphere and luminescence characteristics of Y4MgSi3O13doped with single Ce3+ions and Ce3+,Tb3+ions have been studied. The excitation and emission spectra of phosphors is determined by fluorescence spectrophotometer. The results show that: luminous intensity of Y4MgSi3O13:Tb3+phosphors increased after doped with Ce3+ions and the optimal doping concentration of Ce3+is 0.04. Y3.94MgSi3O13: 0.02Tb3+,0.04Ce3+green phosphor has the best luminescence characteristics under reduction atmosphere(H2:N2=1:3) at 1000°C, the phosphor gives intense green emission at 550nm originating from the5D4→7F5transition of Tb3+ions.

Effects of removing temperature of reduction gas on the luminescence characteristics of Li2BaSiO4:0.003EU2+ green phosphor

2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040159
Author(s):  
Jie Li ◽  
Yang-Ming Lu ◽  
Qing-Hao Yang ◽  
Cheng-Fu Yang
Keyword(s):  
Red Light ◽  
Green Light ◽  
Emission Spectra ◽  
Solid State Reaction Method ◽  
Green Phosphor ◽  
Xrd Pattern ◽  
Light Emitting ◽  
Reducing Gas ◽  
White Light Emitting Diodes ◽  
Luminescence Characteristics

We had successfully synthesized green-emitting phosphors based on Li2BaSiO4 material activated by bivalent europium ions (Eu[Formula: see text]) using a solid-state reaction method in a reducing gas environment and investigated their luminescence properties. The Li2BaSiO4:0.003Eu[Formula: see text] (LSB-Eu) phosphors were synthesized at 850[Formula: see text]C for 1 h, and the reduction gas was removed at 500[Formula: see text]C, 600[Formula: see text]C, 700[Formula: see text]C and 800[Formula: see text]C, respectively. XRD pattern showed that the Li2BaSiO4, Ba2SiO4 and Li4SiO4 phases were observed in the synthesized Li2BaSiO4 composition. As the reduction gas was removed at 800[Formula: see text]C, the LSB-Eu phosphor emitted a weak red light rather than a green light. Two weak emission peaks were found at about 588 nm and 613 nm corresponding to [Formula: see text] and [Formula: see text] transitions. As temperature to remove the reduction gas was lower than 800[Formula: see text]C, the emission spectra of LSB-Eu phosphors reveled a broad peak centered at 501 nm, which emitted a green color. The intensity of photoluminescence excitation (PLE) photoluminescence emission (PL) spectra increased as the removing temperature was decreased from 700[Formula: see text]C to 500[Formula: see text]C and saturated at 500[Formula: see text]C. These results show that LSB-Eu can be a noteworthy candidate of green-emitting phosphor for the investigation of white light-emitting diodes (WLEDs).

Insights into a novel garnet-based yellowish-green phosphor: structure, luminescence properties and application for warm white light-emitting diodes

CrystEngComm ◽  
2019 ◽  
Vol 21 (40) ◽  
pp. 6100-6108 ◽  
Author(s):  
Xicheng Wang ◽  
Yaxin Cao ◽  
Qi Wei ◽  
Xiao Liu ◽  
Xiaoyu Liao ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Green Emission ◽  
Luminescence Properties ◽  
Green Phosphor ◽  
Light Emitting ◽  
Yellowish Green ◽  
Warm White Light ◽  
White Light Emitting Diodes

Efficient and stable yellowish-green emission has been achieved in the garnet-based phosphor CYAS:Ce3+.

Energy Transfer and Spectroscopic Characterization of New Green Emitting Li3Ba2Gd3(WO4)8:Tb3+ Phosphor

2018 ◽  
Vol 281 ◽  
pp. 686-691 ◽  
Author(s):  
Wen Lei Guo ◽  
Yan Ting Jiao ◽  
Ping Shun Wang ◽  
Qi Liu ◽  
Shan Liu ◽  
...  
Keyword(s):  
Critical Concentration ◽  
Green Emission ◽  
Spectroscopic Characterization ◽  
Solid State Method ◽  
Light Emitting ◽  
X Ray ◽  
Optimal Doping Concentration ◽  
White Light Emitting Diodes ◽  
Ray Patterns

A new tungstate family, Li3Ba2Gd3(WO4)8doped with Tb3+is synthesized by using a conventional high-temperature solid-state method to explore new pure green phosphors for white light-emitting diodes (WLEDs). The results from the X-Ray patterns show that the crystal structures of the hosts are composed of tungstate zigzags and the Gd3+-Gd3+units, which are isolated by the [WO4]2-groups. The critical concentration of Tb3+is up to x=2.0 in the singly doped phosphors, which is ascribed to the interaction of the isolated Gd3+ions being mitigated by [WO4]2-groups. The characteristic green emission peaks at around 547 nm are also observed, which result from the5D4→7F5transition of Tb3+ions, and the optimal doping concentration is x=2.0.

Synthesis and Luminescent Properties of Gd2MoO6:Eu3+

2015 ◽  
Vol 15 (10) ◽  
pp. 7765-7769 ◽  
Author(s):  
Sook Hyun Kwon ◽  
Byung Kee Moon ◽  
Jung Hyun Jeong ◽  
Hyun Kyoung Yang ◽  
Jung Hwan Kim
Keyword(s):  
Charge Transfer Band ◽  
Sol Gel ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Light Emitting ◽  
Diffraction Patterns ◽  
White Light Emitting Diodes ◽  
Electron Microscope Image

A series of 6 mol% Eu3+ doped Gd2MoO6 samples were prepared by using the sol–gel method. The X-ray diffraction patterns of the samples confirmed their monoclinic structure after they were annealed at 1300 °C, and a scanning electron microscope image revealed closely packed particles. The excitation spectra showed that the intensity of the excitation band decreased and the charge transfer band shifted from 370 to 350 nm with decreasing sintering temperature. The emission spectra are dominated by the hypersensitive forced electron dipolar transition 5D0 → 7F2 at 612 nm. The as synthesized phosphor can be used as a red phosphor in white light emitting diodes.

Synthesis and Luminescent Properties of Red Phosphor BaY2O4: Eu3+ for White Light-Emitting Diodes

2013 ◽  
Vol 811 ◽  
pp. 181-185 ◽  
Author(s):  
Lan Tu Ya Wu
Keyword(s):  
Sol Gel ◽  
Red Light ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Electric Dipole Transition ◽  
Excitation Spectra ◽  
Excitation Peak ◽  
Red Phosphor ◽  
Light Emitting ◽  
White Light Emitting Diodes

The rare-earth Eu3+doped BaY2O4red phosphor synthesized by citric acid sol-gel method. The structure, morphology and composition of the red phosphor were characterized by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. The results show that the distribution of the pure phase BaY2O4: Eu3+particles after annealing at 800 °C was irregular, small size of particle is 0.2 μm to 0.4 μm. The excitation spectra of synthesized phosphor at 610 nm monitoring were composed of a broadband and a series of sharp peaks, the strongest excitation peak at 466 nm, the secondly at 395nm. It was indicated that BaY2O4: Eu3+phosphor matching with the widespread applied the output wavelengths of UV LED and blue LED chips. The main emission spectra of samples under blue light excitation is Eu3+ions5D07F2electric dipole transition with a strong red light, so that the BaY2O: Eu3+phosphor may be a better candidate for red component for white LED.

A novel green phosphor LaMgAl11O19:Ho3+ for near-UV/blue light-pumped white light-emitting diodes

2015 ◽  
Vol 618 ◽  
pp. 182-185 ◽  
Author(s):  
Xin Min ◽  
Minghao Fang ◽  
Zhaohui Huang ◽  
Hao Liu ◽  
Yan’gai Liu ◽  
...  
Keyword(s):  
Blue Light ◽  
White Light ◽  
Light Emitting Diodes ◽  
Green Phosphor ◽  
Light Emitting ◽  
White Light Emitting Diodes

scholarly journals Broad near-ultraviolet and blue excitation band induced dazzling red emissions in Eu3+-activated Gd2MoO6 phosphors for white light-emitting diodes

RSC Advances ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 3170-3178 ◽  
Author(s):  
Peng Du ◽  
Yue Guo ◽  
Soo Hyun Lee ◽  
Jae Su Yu
Keyword(s):  
Citric Acid ◽  
White Light ◽  
Light Emitting Diodes ◽  
Sol Gel ◽  
Excitation Band ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Blue Excitation ◽  
White Light Emitting Diodes

A series of Eu3+-activated Gd2MoO6 phosphors were synthesized via a citric acid-assisted sol–gel route.

scholarly journals Luminescence of SiO2-BaF2:Tb3+, Eu3+ Nano-Glass-Ceramics Made from Sol–Gel Method at Low Temperature

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 259
Author(s):  
Natalia Pawlik ◽  
Barbara Szpikowska-Sroka ◽  
Tomasz Goryczka ◽  
Ewa Pietrasik ◽  
Wojciech A. Pisarski
Keyword(s):  
Sol Gel ◽  
Three Dimensional ◽  
Glass Ceramics ◽  
Emission Spectra ◽  
Scanning Calorimetry ◽  
Light Emitting ◽  
Co Doping ◽  
Dsc Measurements ◽  
Decay Times

The synthesis and characterization of multicolor light-emitting nanomaterials based on rare earths (RE3+) are of great importance due to their possible use in optoelectronic devices, such as LEDs or displays. In the present work, oxyfluoride glass-ceramics containing BaF2 nanocrystals co-doped with Tb3+, Eu3+ ions were fabricated from amorphous xerogels at 350 °C. The analysis of the thermal behavior of fabricated xerogels was performed using TG/DSC measurements (thermogravimetry (TG), differential scanning calorimetry (DSC)). The crystallization of BaF2 phase at the nanoscale was confirmed by X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM), and the changes in silicate sol–gel host were determined by attenuated total reflectance infrared (ATR-IR) spectroscopy. The luminescent characterization of prepared sol–gel materials was carried out by excitation and emission spectra along with decay analysis from the 5D4 level of Tb3+. As a result, the visible light according to the electronic transitions of Tb3+ (5D4 → 7FJ (J = 6–3)) and Eu3+ (5D0 → 7FJ (J = 0–4)) was recorded. It was also observed that co-doping with Eu3+ caused the shortening in decay times of the 5D4 state from 1.11 ms to 0.88 ms (for xerogels) and from 6.56 ms to 4.06 ms (for glass-ceramics). Thus, based on lifetime values, the Tb3+/Eu3+ energy transfer (ET) efficiencies were estimated to be almost 21% for xerogels and 38% for nano-glass-ceramics. Therefore, such materials could be successfully predisposed for laser technologies, spectral converters, and three-dimensional displays.

Synthesis and Characterization of CaMgSi2O6 Activated by Eu2+

2016 ◽  
Vol 881 ◽  
pp. 30-34
Author(s):  
Agatha Matos Misso ◽  
Hermi F. Brito ◽  
Lucas C.V. Rodrigues ◽  
Vinicius R. Morais ◽  
Chieko Yamagata
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Sol Gel ◽  
Solid State Reactions ◽  
Phase Identification ◽  
Molten Salt Method ◽  
Persistent Luminescence ◽  
Light Emitting ◽  
Fluorescent Lamps ◽  
White Light Emitting Diodes

Rare earth silicate based MnMgSi2O5+n (M = Ca, Sr or Ba and n=1-2) phosphors, have attracted interest of researchers due to their high efficiency as a host, excellent thermal and chemical stability and high brightness adding to their low cost. These phosphors showed great potential in various applications such as fluorescent lamps, white light emitting diodes, and display components. High temperature solid-state reactions are usually employed to synthesize those compounds. This paper proposes an alternative method of obtaining nanophosphor host based on Eu-doped CaMgSi2O6 (CMS:Eu), persistent luminescence phosphor. Sol gel technique combined to a modified molten salt method was used. The resulted powder was calcined for 3h under an atmosphere of 5% H2 and 95% Ar2. Phase identification by XRD and the measurements of photoluminescence (PL) and photoluminescence excitation (PLE) were performed. Single phased CMS:Eu with persistent luminescence characteristics was prepared.

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