Photoluminescence Properties and Energy Transfer in a Novel Yellow Emitting Phosphor GdTaO4:Dy3+

2016 ◽  
Vol 16 (4) ◽  
pp. 3994-3997 ◽  
Author(s):  
Huijuan Zhang ◽  
Xinyu Tan ◽  
Yuhua Wang

The phosphor Dy3+ doped M type gadolinium orthotantalate GdTaO4 was prepared successfully by traditional solid state reaction and the photoluminescence of GdTaO4: xDy3+ (0.01 ≤ x ≤ 0.10) has been investigated under ultraviolet and vacuum ultraviolet excitation. In the excitation spectra of GdTaO4:Dy3+, the overlap appears between the host lattice excitation, the excitation lines of Gd3+ and the f–f transitions of Dy3+, which indicates that the energy transfer could occur from the host to the Dy3+ ions. In the emission spectra of the samples, the intense emissions of Dy3+ have been expectably revealed both upon excitation at 365 nm and 147 nm. And the chromaticity coordinates of GdTaO4: xDy3+ have been correspondingly calculated. The results indicate that GdTaO4:Dy3+ would be a novel yellow emitting phosphor applied in light emitting diodes (LEDs), plasma display panels (PDPs) and mercury-free fluorescent tubes.

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.


2013 ◽  
Vol 341-342 ◽  
pp. 229-232
Author(s):  
Bi Tao Liu ◽  
Lin Lin Peng

The photoluminescent properties of Na, Bi co-doped CaWO4:Eu3+ phosphor under vacuum ultraviolet (VUV) region excited was investigated. A red emission of CaWO4:Eu3+ can be observed under 147 nm excitation. It was also found that the photoluminescence intensity of Na doped CaWO4:Eu3+ would be enhanced than the un-doped phosphors due to Na+ ions would act as a charge compensator and it can restrict the generation of defects in CaWO4:Eu3+. Additionally, the photoluminescence enhancement of Na+, Bi3+ co-doped CaWO4:Eu3+ should due to the energy transfer between WO42-, Bi3+ and Eu3+, and Bi3+ ions would act as a medium for the energy transfer, via WO42-Bi3+Eu3+. These are expected to be applying in plasma display panels.


2021 ◽  
Vol 28 (1) ◽  
pp. 205-214
Author(s):  
Shuai Wang ◽  
Pengfei Wang ◽  
Yongfeng Ruan ◽  
Youfa Wang ◽  
Shouchao Zhang

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.


2014 ◽  
Vol 1052 ◽  
pp. 203-206
Author(s):  
Zhi Long Wang ◽  
Shi Qin Wang ◽  
Nin Yao ◽  
Xing Min Wei

(Gd,La)2-x O2CO3:Eux3+(0.01 ≤x≤0.04) were synthesized via a flux method at 400°C, and their photoluminescence properties under vacuum ultraviolet (VUV) excitation were examined. The excitation spectra showed two bands in the region from 125 nm to 300 nm, the first band centered at 190 nm was ascribed to absorption of related CO32- complex, and the second broad band centered at 246nm and 278nm in Gd2O2CO3:Eu3+ was ascribed to the charge transfer band of O2-→ Eu3+. Series samples exhibited red emission at around 611 nm under vacuum ultraviolet excitation corresponding to the 5D0→ 7F2.transition of Eu3+.


2021 ◽  
Vol 1167 ◽  
pp. 57-66
Author(s):  
Muhammad Khurram ◽  
Florian Baur ◽  
Thomas Juestel

Red emitting Mn4+ doped oxides are a promising class of materials to improve the colour rendering and luminous efficacy of phosphor-converted light-emitting diodes (pcLEDs). For pcLEDs, the optical properties are crucial w.r.t commercial acceptance. In this work, luminescence spectra and decay curves of Sr2YNbO6, Sr2YTaO6 and Sr2LaNbO6 have been recorded, other Mn4+ doped phosphors show that quenching occurs through thermally activated crossover between the 4T2 excited state and 4A2 ground state. The quenching temperature can be optimized by designing the host lattice in which Mn4+ has a high 4T2 state energy. The main target is to study the influence of the above-mentioned host materials on the emission spectra, PL quenching, and quantum yield of the deep red Mn4+ ion. The present study provides detailed insights into temperature and concentration quenching of Mn4+ emission and can be used to realize superior narrow-band red Mn4+ phosphors for horticultural lighting.


1999 ◽  
Vol 598 ◽  
Author(s):  
J. Morgado ◽  
R. Iqbal ◽  
G. Yahioglu ◽  
L. R. Milgrom ◽  
S. C. Moratti ◽  
...  

ABSTRACTThe solid state luminescent properties of new statistical copolymers of 2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene and a porphyrin-substituted phenylene vinylene are reported. The photoluminescence, PL, emission shows an efficient energy transfer to the porphyrin, in spite of the small absorption coefficient of the porphyrin in the wavelength range of the poly [2-methoxy-5-(2'- ethylhexyloxy)-1,4-phenylene vinylene], MEH-PPV, emission. At a porphyrin content of 0.25%, by weight, the emission is already dominated by the porphyrin. The PL efficiency of these copolymers is significantly reduced from the value of 13% for MEH-PPV down to 3% for the copolymer with 10.84% of porphyrin. Efficient energy transfer is also observed in the emission spectra of light-emitting diodes.


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.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Jing Gou ◽  
Dongyang Zhang ◽  
Binxun Yu ◽  
Jing Wang ◽  
Shengzhong Liu

A novel reddish orange phosphor CaIn2O4:Sm3+codoped with Zn2+or Al3+ions was prepared by solid state reaction and their luminescence properties were investigated under near ultraviolet excitation. The strategy of Zn2+or Al3+ions codoping was used with the aim to improve the luminescence properties of CaIn2O4:Sm3+, but the concrete effects of the two ions is different. The introduction of Zn2+ions can produceZnIn'defects that favor charge balance in CaIn2O4:Sm3+to facilitate its photoluminescence. The effect of Al3+ions codoping can effectively transfer energy from charge-transfer absorption band to characteristic transition of Sm3+ions, utilizing more energy from host absorption for the photoluminescence of Sm3+ions. Based on these mechanisms, the luminescence intensity of CaIn2O4:0.6%Sm3+was enhanced to 1.59 times and 1.51 times when codoping amount of Zn2+and Al3+ions reached 0.6%. However, the chromaticity coordinates of CaIn2O4:0.6%Sm3+almost did not have any changes after Zn2+ions or Al3+ions codoping; those are still located at reddish orange region. The excellent luminescence properties of CaIn2O4:0.6%Sm3+,0.6%Zn2+and CaIn2O4:0.6%Sm3+,0.6%Al3+demonstrate that they both have potential application value as new-style reddish orange phosphors on light-emitting diode.


2013 ◽  
Vol 401-403 ◽  
pp. 796-799 ◽  
Author(s):  
Jia Yue Sun ◽  
Dian Peng Cui ◽  
Bing Xue ◽  
Guang Chao Sun

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.


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