The Structure and Photoluminescence Properties of Ca3Si2O7: Eu2+ Phosphor

2012 ◽  
Vol 509 ◽  
pp. 192-196
Author(s):  
Xing Hua Zhang ◽  
Zun Ming Lu ◽  
Fan Bin Meng ◽  
Long Hu ◽  
Xue Wen Xu ◽  
...  

A series of yellow-emitting phosphors based on a silicate host matrix, Ca3-xSi2O7: xEu2+, were prepared by solid-state reaction method. The structure and photoluminescent properties of the phosphors were investigated. The XRD results show that the Eu2+ substitution of Ca2+ does not change the structure of Ca3Si2O7 host. The SEM images display that phosphors aggregate obviously and the shape of the phosphor particle is irregular. The EDX results reveal that the phosphors consist of Ca, Si, O, and Eu elements. The Ca3-xSi2O7: xEu2+ phosphors can be excited at wavelength of 300-490 nm, which is suitable for the emission band of near ultraviolet or blue light-emitting-diode (LED) chips. The phosphors exhibit a broad emission region from 520 to 650 nm and the emission peak centered at 568 nm. The phosphor for has the strongest excitation and emission intensity, and the energy transfer style between Eu2+ ions is quadrupole-quadrupole interaction for higher concentration Eu2+ doped Ca3Si2O7 phosphor. The Ca3-xSi2O7: xEu2+ phosphors can be used as candidates for white LEDs.

Author(s):  
Zhiyuan Li ◽  
Xuhui Zhang ◽  
Ji Wu ◽  
Rui Guo ◽  
Lan Luo ◽  
...  

Non-rare-earth Mn4+-doped oxide red phosphors received increasing attention in the white light-emitting diode (LED) field for their admirable chemical stability and spectral properties. Here, a new inequivalent double-site substituted Mn4+-doped...


2021 ◽  
Author(s):  
Chao Yang ◽  
Guohua Song ◽  
Jianwen Miao ◽  
Tingting Fan

Abstract The YAG: Eu 3+ fluorescent glass for NUV(near ultraviolet) white LEDs was obtained firstly by synthesizing Y 3 Al 5 O 12 (YAG): Eu 3+ precursors through a simple co-precipitation method, and then mixing precursor with B 2 O 3 -Al 2 O 3 -SiO 2 -Na 2 O-BaO glass powder calcined at 1400°C for 2.5 hours. The as-prepared YAG glass-ceramic phosphor was investigated by DTA, XRD, SEM, and photoluminescence (PL). Influence of YAG: Eu 3+ precursor and Eu 3+ doping on excitation and emission spectra also have been studied. The results show that: the phosphor's emission peak located at 393nm is correspond to the 7 F 0 - 5 L 6 transition of Eu 3+ ions, which matches good with UV LED chips; the phosphor gives intense emission at 593nm originating from the 5 D 0 - 7 F 1 transition of Eu 3+ ions. When the YAG precursor is 0.9g and amount of Eu 3+ doped is 0.08, the fluorescence excitation spectra of glass and emission spectra of the peak intensity reach its maximum value. The YAG: Eu 3+ fluorescence glass could be a promising material for the production of near ultraviolet chip white light-emitting diode.


2011 ◽  
Vol 295-297 ◽  
pp. 547-550
Author(s):  
Jia Yue Sun ◽  
Jin Li Lai ◽  
Hai Yan Du

A series of new Na3CaB5O10:Eu3+ phosphor was synthesized by a solid-state reaction method, and its luminescent properties were investigated. The phase formation of phosphors was confirmed by X-ray powder diffraction (XRD). The excitation spectra exhibited that the phosphors could be effectively excited by near ultraviolet (392 nm) and blue (464 nm) light, which perfectly match the emission wavelength of near-UV light-emitting diodes (LEDs). The emission spectra showed that two characteristic red emission lines peaking at 592 and 613 nm can be obtained upon 394 and 463 excitation with the chromaticity coordinates of (0.6347, 0.3649), which are due to 5D0- 7F1 and 5D0-7F2transitions of Eu3+ ions. The effect of Eu3+ concentration on the emission spectrum of Na3CaB5O10:Eu3+ phosphor was studied. The results showed that the emission intensity increased with increasing Eu3+ concentration, and then decreased because of concentration quenching. The obtained results indicated that this phosphor could be a promising candidate for near-UV white LEDs.


Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2240
Author(s):  
Haggeo Desirena ◽  
Jorge Molina-González ◽  
Octavio Meza ◽  
Priscilla Castillo ◽  
Juan Bujdud-Pérez

A series of Tb3+/Eu3+-codoped phosphor ceramic plates with a high color rendering index (CRI) for a near-ultraviolet light emitting diode (LED) were fabricated. Color emission can be tuned from green to reddish as a function of Eu3+ concentration. By doping only 0.15 mol% of Eu3+ concentration, a comfortable warm white emission is promoted as a result of simultaneous emissions of Tb3+ and Eu3+ ions. A theoretical model is proposed to calculate the contributions of the emitted color of the donor (Tb3+) and acceptor (Eu3+) ions in terms of europium concentration. The energy transfer from Tb3+ to Eu3+ ions is corroborated by the luminescence spectra and decay time of Tb3+, with a maximum energy transfer efficiency of 76% for 28 mol% of Tb3+ and 14 mol% of Eu3+. Warm white LEDs were constructed using a 380 nm UV chip and showed a CRI of 82.5, which was one of highest values reported for Tb3+/Eu3+-codoped samples. Color-correlated temperature (CCT), color coordinate (CC), and luminous efficacy (LE) were utilized to know the potentials as a phosphor converter in solid-state lighting.


Author(s):  
Qianqian Zhang ◽  
Guogang Li ◽  
Peipei Dang ◽  
Dongjie Liu ◽  
Dayu Huang ◽  
...  

Near-infrared emitting phosphor-converted light-emitting diode (NIR pc-LED) attracts much attention as the promising applications in night vision, biosensor, food composition and freshness measurement area and so on, while the discovery...


Author(s):  
Yan Zhang ◽  
Yanjie Liang ◽  
Shihai Miao ◽  
Dongxun Chen ◽  
Shao Yan ◽  
...  

A series of Cr3+-doped BaMSi3O9 (M = Zr, Sn, Hf) near-infrared emitting phosphors with tunable luminescence properties have been successfully synthesized by using a simple solid-state reaction method. The developed...


2008 ◽  
Vol 45 (4) ◽  
pp. 25-32 ◽  
Author(s):  
L. Dimitrocenko ◽  
J. Grube ◽  
P. Kulis ◽  
G. Marcins ◽  
B. Polyakov ◽  
...  

AlGaN-InGaN-GaN Near Ultraviolet Light Emitting DiodeA 382-nm InGaN/AlGaN light-emitting diode (LED) was made on a sapphire substrate by metal-organic vapour phase deposition (MOCVD) technique. Growing of the undoped and Si-doped GaN and AlxGa1-xN monocrystalline layers with a surface roughness of < 1 nm required for making light emitting devices has been carried out. To enhance the LED emission efficiency, a modified symmetric composition of an active single quantum well (SQW) structure was proposed. In addition to the conventional p-doped AlGaN:Mg electron overflow blocking barrier, ann-doped AlGaN:Si SQW barrier layer in the structure was formed that was meant to act as an additional electron tunneling barrier.


2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744058
Author(s):  
Rong Yang ◽  
Huidong Tang

A novel phosphor, K2MgSiO4:Eu[Formula: see text], was synthesized by a solid-state reaction method. The phase formation was checked by X-ray powder diffraction. The photoluminescence excitation, emission spectra, decay curve and CIE coordinates of samples with different Eu[Formula: see text] ion concentrations were investigated in detail. The excitation spectra show a broad wavelength range of 225–470 nm. The K2MgSiO4:Eu[Formula: see text] phosphors exhibit highly red emission peaking at about 616 nm which is assigned to the 5D[Formula: see text]F2 transition of Eu[Formula: see text]ions under the excitation of near-ultraviolet (NUV) (394 nm) light. The critical quenching concentration of Eu[Formula: see text] doped in the K2MgSiO4: Eu[Formula: see text] phosphors was about 10 mol.% and the concentration quenching mechanism was dipole–dipole interactions between Eu[Formula: see text] ions. The results indicate that K2MgSiO4:Eu[Formula: see text] is a potential red phosphor candidate for NUV-pumped white light emitting diodes.


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