Photoluminescence and Energy Transfer from Sm3+ to Eu3+ in Na3YSi2O7 Phosphor for Light-Emitting Diodes

2014 ◽  
Vol 597 ◽  
pp. 117-120 ◽  
Author(s):  
Jia Yue Sun ◽  
Dian Peng Cui ◽  
Qiu Mei Di ◽  
Qi Guang Xu ◽  
Liu Han
Keyword(s):  
Energy Transfer ◽  
Uv Light ◽  
Red Light ◽  
Emission Spectra ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
Light Emitting ◽  
X Ray ◽  
Effective Energy Transfer ◽  
Light Excitation

A series of Na3YSi2O7: Eu3+, Sm3+ samples have been synthesized via solid-state reaction technique. The phase structure and luminescence properties are characterized using powder X-ray diffraction, photoluminescence excitation and emission spectra. Effective energy transfer occurs from Sm3+ to Eu3+ and Sm3+/Eu3+-codoped Na3YSi2O7 shows more intense red light compared to that of Eu3+-doped sample under UV light excitation.

Photoluminescence and Energy Transfer of Ce3+ and Tb3+ Co-Doped Ba5(PO4)3Cl Phosphor for Light-Emitting Diodes

2013 ◽  
Vol 401-403 ◽  
pp. 796-799 ◽  
Author(s):  
Jia Yue Sun ◽  
Dian Peng Cui ◽  
Bing Xue ◽  
Guang Chao Sun
Keyword(s):  
Energy Transfer ◽  
Single Phase ◽  
Uv Light ◽  
Green Light ◽  
Emission Spectra ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Effective Energy Transfer ◽  
Light Excitation

Single-phase Ba5(PO4)3Cl:Ce3+,Tb3+ (BPCl:Ce3+,Tb3+) samples have been synthesized via solid-state reaction method. The phase structure and luminescence properties are characterized using powder X-ray diffraction (XRD), photoluminescence excitation and emission spectra. Effective energy transfer occurs from Ce3+ to Tb3+ due to the observed spectral overlap between the emission band of Ce3+ and the excitation band of Tb3+. Ce3+/Tb3+-codoped Ba5(PO4)3Cl shows more intense yellowish-green light compared to that of Tb3+-doped sample under UV light excitation.

scholarly journals A novel UV pumped yellow-emitting phosphor Ba2YAlO5:Dy3+ for white light-emitting diodes

2019 ◽  
Vol 79 ◽  
pp. 03005
Author(s):  
Bin Deng ◽  
Jun Chen ◽  
Chong-song Zhou ◽  
Hui Liu
Keyword(s):  
Dopant Concentration ◽  
Uv Light ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Solid State Route ◽  
Light Excitation ◽  
Diffraction Patterns ◽  
White Light Emitting Diodes ◽  
Uv Leds

A series of novel Dy3+ activated aluminate Ba2Y1-xDyxAlO5 (x = 0.01–0.30) red-emitting phosphors were synthesized through a high-temperature solid-state route at 1380°C. The X-ray diffraction patterns revealed that the samples were well crystallized in the space group P21/c (No. 14). The spectrum analysis revealed that under UV light excitation, Ba2YAlO5:Dy3+ phosphor exhibited blue and yellow peaks corresponding to 4F9/2–6H15/2 transition and 4F9/2–6H13/2 transition, respectively. The optimum dopant concentration of Dy3+ ions is around 2 mol% and the critical transfer distance of Dy3+ is calculated as 29 Å. The concentration quenching mechanism between Dy3+ has been investigated. Results indicate that Ba2YAlO5:Dy3+ offers the excellent optical properties as a potential yellow-emitting phosphor candidate for n-UV LEDs.

ROOM TEMPERATURE PHOTOLUMINESCENCE OF POLYCRYSTALLINE SIC PREPARED FROM CARBON-SATURATED SI MELT

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Composition And Structure ◽  
Light Excitation ◽  
Scanning Electron

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.

Luminescence Properties of Self-Activated M3(VO4)2 (M = Mg, Ca, Sr, and Ba) Phosphors Synthesized by Solid-State Reaction Method

2016 ◽  
Vol 16 (4) ◽  
pp. 3684-3689 ◽  
Author(s):  
Xin Min ◽  
Zhaohui Huang ◽  
Minghao Fang ◽  
Yan’gai Liu ◽  
Chao Tang ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Uv Light ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Reaction Method ◽  
X Ray ◽  
Yield Decrease

In this paper, M3(VO4)2 (M = Mg, Ca, Sr, and Ba) self-activated phosphors were prepared by a solid-state reaction method at 1,000 °C for 5 h. The phase formation and micrographs were analyzed by X-ray diffraction and scanning electron microscopy. The Ca3(VO4)2 phosphor does not show any emission peaks under excitation with ultraviolet (UV) light. However, the M3(VO4)2 (M = Mg, Sr, and Ba) samples are effectively excited by UV light chips ranging from 200 nm to 400 nm and exhibit broad emission bands due to the charge transfer from the oxygen 2p orbital to the vacant 3d orbital of the vanadium in the VO4. The color of these phosphors changes from yellow to light blue via blue-green with increasing ionic radius from Mg to Sr to Ba. The luminescence lifetimes and quantum yield decrease with the increasing unit cell volume and V–V distance, in the order of Mg3(VO4)2 to Sr3(VO4)2 to Ba3(VO4)2. The emission intensity decreases with the increase of temperatures, but presents no color shift. This confirms that these self-activated M3(VO4)2 phosphors can be suggested as candidates of the single-phase phosphors for light using UV light emitting diodes (LEDs).

scholarly journals Preparation and Up-Conversion Luminescence of Yb3+/Er3+/GZO Ceramics

2018 ◽  
Vol 20 (3) ◽  
pp. 15-19
Author(s):  
Guomin Li ◽  
Bing Wang ◽  
Rui Wang ◽  
Huiling Liu
Keyword(s):  
Red Light ◽  
Emission Spectra ◽  
Green Emission ◽  
Power Curve ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Green Is ◽  
Xrd Pattern ◽  
X Ray ◽  
State Method

Abstract Yb3+/Er3+/GZO ceramics have been synthesized with high temperature solid-state method. The phase and structure of the Yb3+/Er3+/GZO ceramics were characterized by X-ray diffraction (XRD). The XRD pattern that following ions Yb3+, Er3+ and Ga3+ were well doped into the ZnO lattice. Effi cient visible up-conversion (UC) red and green emission were observed under 980 nm excitation. The mechanism of the UC luminescence is investigated on the basis of the UC luminescence emission spectra, the power curve and energy level diagram. The infl uence of doping ions to the intensity ratio of red to green is analyzed and high purity of red light (red/green = 29.9) is fi nally obtained.

scholarly journals The Role of Bismuth on the Best Red Light Emitting Nanophosphors

2021 ◽  
Vol 9 (6) ◽  
pp. 55-59
Author(s):  
Vini. K ◽  
Padmakumar H. ◽  
K.M. Nissamudeen
Keyword(s):  
Rare Earths ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Combustion Method ◽  
Processing Temperature ◽  
X Ray Diffraction ◽  
Luminescence Enhancement ◽  
Light Emitting ◽  
X Ray

This paper explains the role of bismuth in the luminescence enhancement of Y2O3 :Eu nanophosphors prepared by Combustion method. Bi ions serve as effective sensitizers for visible emitting rare earths for Light Emitting Diodes. From the X-ray diffraction studies, bismuth co-activated nanophosphors exhibit an early crystallization. Bismuth incorporation not only results in the luminescence enhancement at 612 nm, due to 5D0 to 7F2 transition but also reduces the processing temperature for intense photoemission.

A novel stibium phosphate, LiBa(SbO)2(PO4)3: synthesis, crystal structure and RE3+-activated (RE = Tb3+ and Eu3+) fluorescence performance

2019 ◽  
Vol 75 (9) ◽  
pp. 1234-1242
Author(s):  
Shi-Rui Zhang ◽  
Dan Zhao ◽  
Rui-Juan Zhang ◽  
Lin-Ying Shi ◽  
Shao-Jie Dai ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Red Light ◽  
Three Dimensional ◽  
Emission Spectra ◽  
Antimony Oxide ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
Host Matrix ◽  
Rietveld Refinements ◽  
Light Emitting

A new stibium phosphate, lithium barium bis(antimony oxide) tris(phosphate), LiBa(SbO)2(PO4)3, was prepared by the molten salt method with LiF as the flux. The crystal structure consists of an original three-dimensional anionic framework of [(SbO)2(PO4)3]∞ built from PO4 tetrahedra sharing their corners with SbO6 octahedra. This framework delimits one-dimensional tunnels where the lithium(I) and barium(II) ions are located. The UV–Vis spectrum shows that LiBa(SbO)2(PO4)3 was transparent from 350 to 800 nm, and is thus suitable as a luminescent host matrix. We then used Tb3+ and Eu3+ activators to test its luminous performance and the purities of the prepared phosphors were studied by powder X-ray diffraction analysis with Rietveld refinements. Photoluminescence (PL) studies reveal that the emission spectra of 1 mol% RE3+-doped (RE = Tb and Eu) samples can be excited by 371 and 394 nm light, emitting green and orange–red light, respectively, for Tb3+ and Eu3+. The CIE coordinates were measured to be (0.295, 0.571) and (0.6027, 0.3967), and the luminescent lifetimes were calculated as 0.178 and 1.159 ms, respectively.

New red phosphor Na3EuB8O15 with an open-window tubular structure

2021 ◽  
Vol 77 (5) ◽  
pp. 235-239
Author(s):  
Wen-Yan Bi ◽  
Wei Wang ◽  
Rui-Juan Zhang
Keyword(s):  
Uv Light ◽  
Emission Spectra ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Triclinic Space Group ◽  
Chromaticity Index ◽  
Open Window ◽  
Light Excitation ◽  
Cie Chromaticity

A new rare-earth polyborate, trisodium europium octaborate, Na3EuB8O15, was prepared using the high-temperature molten-salt method and structurally determined by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic space group P\overline{1} and contains a one-dimensional [B8O15]∞ tube structure that is constructed from BO3 and BO4 polyhedra. The Eu3+ and Na+ cations reside in this structure to ensure cohesion and neutrality. The excitation spectra, emission spectra, decay time and Commission Internationale de l'Éclairage (CIE) chromaticity index of Na3EuB8O15 were studied. Under near-UV light excitation (393 nm), the polyborate shows an intense red emission, which mainly originates from the highest intensities of the 5D0→7F1 and 5D0→7F2 transitions.

scholarly journals Tunable Yellow-Red Emission via Energy Transfer in Dy3+, Mn4+: NaLaMgWO6 Phosphors for UV-Excited LED

2021 ◽  
Author(s):  
yonghua wu ◽  
Fugui Yang ◽  
Fengpo Yan ◽  
Ruijuan Zuo
Keyword(s):  
Energy Transfer ◽  
Solid State ◽  
Solid State Reaction ◽  
Red Light ◽  
Emission Spectra ◽  
Excitation Source ◽  
Red Emission ◽  
Phase Purity ◽  
Emission Performance ◽  
Light Excitation

Abstract The Dy3+, Mn4+: NaLaMgWO6 phosphors are synthesized successfully using the technique of solid-state reaction at 1150 ℃. The XRD and SEM-EDS are measured to analyze the phase purity. The concentrations of Dy3+, Mn4+, Mg2+, Na+, La3+ and W6+ are measured by ICP. The absorption and excited spectra are presented, which indicate the 390 nm is suitable for the tunable yellow-red light excitation. Using the 390 nm LED as the excitation source, the emission spectra with different doped concentrations ratios of Dy3+to Mn4+ are obtained, which shows good tunable yellow-red emission performance.

scholarly journals Towards a Correlation between Structural, Magnetic, and Luminescence Properties of CeF3:Tb3+ Nanocrystals

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2980
Author(s):  
Cristina Bartha ◽  
Corina Secu ◽  
Elena Matei ◽  
Catalin Negrila ◽  
Aurel Leca ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Susceptibility ◽  
Uv Light ◽  
Nanocrystalline Phase ◽  
Magnetization Curves ◽  
X Ray Diffraction ◽  
Green Luminescence ◽  
X Ray ◽  
Light Excitation ◽  
Paramagnetic Properties

In this study, we report on the structural, magnetic, and optical properties of Tb3+-doped CeF3 nanocrystals prepared via a polyol-assisted route, followed by calcination. X-ray diffraction analysis and electron microscopy investigations have shown the formation of a dominant Ce0.75F3 nanocrystalline phase (of about 99%), with a relatively uniform distribution of nanocrystals about 15 nm in size. Magnetization curves showed typical paramagnetic properties related to the presence of Ce3+ and Tb3+ ions. The magnetic susceptibility showed a weak inflexion at about 150 K, assigned to the cerium ions’ crystal field splitting. Under UV light excitation of the Ce3+ ions, we observed Tb3+ green luminescence with a quantum yield of about 20%.

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