Synthesis and Luminescent Properties of Violet-Ultraviolet Long Afterglow Phosphors

2010 ◽  
Vol 663-665 ◽  
pp. 170-176
Author(s):  
Hao Yi Wu ◽  
Yi Hua Hu ◽  
Yin Hai Wang ◽  
Chu Jun Fu ◽  
Feng Wen Kang ◽  
...  
Keyword(s):  
Solid State ◽  
Oxygen Vacancies ◽  
Trap Depth ◽  
Luminescent Properties ◽  
Solid State Reaction Method ◽  
Broad Emission Band ◽  
Suitable Model ◽  
Reaction Method ◽  
Long Afterglow ◽  
Broad Emission

The M1.99MgSi2O7: Ce3+0.01 (M: Ba, Sr, Ca) phosphors were prepared by the solid-state reaction method. All the samples emit the violet-ultraviolet light with a broad emission band from about 330 nm to 500 nm. All the phosphors samples show a long afterglow. The strongest afterglow intensity and the longest decay duration of the afterglow come from the Ca1.99MgSi2O7: Ce3+0.01 sample. It is attributed to the suitable trap depth and the high trap concentration of this sample. The traps of these phosphors are induced by the lattice defects. A suitable model involving the cation vacancies and the oxygen vacancies, which act as the hole traps and the electron traps respectively, is proposed.

Fabrication and Properties of Zinc Silicate Phosphors through Solid State Reaction

2010 ◽  
Vol 160-162 ◽  
pp. 594-598
Author(s):  
Guo Jian Jiang ◽  
Jia Yue Xu ◽  
Hui Shen ◽  
Yan Zhang ◽  
Lin He Xu ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Emission Peak ◽  
Zinc Silicate ◽  
Red Phosphor ◽  
Reaction Method ◽  
Long Afterglow ◽  
Luminescent Mechanism ◽  
Silicate Phosphors

Zinc silicate-based (Zn2SiO4:Eu3+) long afterglow phosphors were produced by solid state reaction method. The effects of borax and Eu2O3 additive on the properties of fabricated products have been studied. The results show that, there is not much difference in phase compositions within the borax additive amount; however, their SEM morphologies are different. Borax additive can increase the grain size of the product. Some sintering phenomena could be observed in the sample with Eu2O3 addition. The fluorescence spectroscopy results indicate that, the emission peak of the sample with Eu3+ additive located at 612nm, which may be a good candidate for red phosphor applications. The luminescent mechanism of Zn2SiO4:Eu3+ is also discussed.

scholarly journals Synthesis and luminescent properties of novel red-emitting M7Sn(PO4)6:Eu3+(M= Sr,Ba) phosphors

2018 ◽  
Vol 12 (1) ◽  
pp. 8-12
Author(s):  
Guo Feng ◽  
Weihui Jiang ◽  
Jianmin Liu ◽  
Cong Li ◽  
Quan Zhang
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Red Light ◽  
Luminescent Properties ◽  
Solid State Reaction Method ◽  
Formula Unit ◽  
Conventional Solid State Reaction ◽  
Light Emitting ◽  
Reaction Method ◽  
Uv Leds

Novel Eu3+-activated M7Sn(PO4)6 (where M = Sr, Ba) red-emitting phosphors were synthesized via conventional solid-state reaction method at 1200 ?C for 2 h. The luminescence properties of the prepared samples and quenching concentration of Sr7-xSn(PO4)6 :xEu3+ and Ba7-xSn(PO4)6 :xEu3+ were investigated. These phosphors can be efficiently excited by UV (395 nm) and visible blue (465 nm) light nicely matching the output wavelengths of the near-UV LEDs and InGaN blue LED chips and emit the red light. The critical concentrations of the Eu3+ activator were found to be 0.175mol and 0.21mol per formula unit for Sr7-xSn(PO4)6 :xEu3+ and Ba7-xSn(PO4)6 :xEu3+, respectively. The M7-xSn(PO4)6 :xEu3+ (M = Sr, Ba) phosphor may be a good candidate for light-emitting diodes application.

scholarly journals Anisotropic Ferro- and Dielectric Properties of Textured Bi4Ti3O12Ceramics Prepared by the Solid-State Reaction Based on Multiple Calcination

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Xiangyu Mao ◽  
Wei Wang ◽  
Hui Sun ◽  
Xiaobing Chen
Keyword(s):  
Activation Energy ◽  
Dielectric Properties ◽  
Solid State ◽  
Solid State Reaction ◽  
Oxygen Vacancies ◽  
Remanent Polarization ◽  
Domain Walls ◽  
Solid State Reaction Method ◽  
Dielectric Anomaly ◽  
Reaction Method

The grain-oriented Bi4Ti3O12(BIT) samples were prepared by the solid-state reaction method with a multicalcination process. The grain-oriented BIT samples exhibit anisotropic structural, ferroelectric, piezoelectric, and dielectric properties. The remanent polarization (2Pr) and the piezoelectric constant (d33) ofa/b- andc-direction BIT ceramics are 49.5 μC cm−2, 22.2 pC N−1and 6.7 μC cm−26.9 pC N−1, respectively. The dielectric anomalies of samples are observed around 157 K and 232 K. The dielectric anomalies at around 157 K are related to oxygen vacancies. The activation energy of the dielectric relaxation of this anomaly is estimated to be 1.36 eV. Another dielectric anomaly at around 232 K is related to polarizable domains and the viscous motion of domain walls.

Effects of Various Fluxes on Synthesis of Deep Red Emitting CaAl12O19:Mn4+ Phosphors

2016 ◽  
Vol 852 ◽  
pp. 454-460 ◽  
Author(s):  
Qiu Hong Zhang ◽  
Hai Yong Ni ◽  
Ling Li Wang ◽  
Fang Ming Xiao
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Luminescent Properties ◽  
Solid State Reaction Method ◽  
Luminescent Intensity ◽  
Reaction Method ◽  
Structure Morphology ◽  
Forming Temperature

Deep red emitting CaAl12-xO19:xMn4+ phosphors were synthesized by solid state reaction method. Various fluxes (BaF2, H3BO3, Na2CO3 and NH4Cl) were added in preparation of the phosphors. The influences of the various fluxes on the crystal structure, morphology and luminescent properties of CaAl12O19:Mn4+ phosphors were studied. The results show that the obtained phosphors with fluxes possessed better luminescent intensity than that of the phosphors without fluxes. The maximum luminescent intensities were found with the following order: H3BO3 (2.0 wt%) > Na2CO3 (0.5 wt%) > NH4Cl (0.3 wt%) > BaF2 (0.1 wt%) > no flux. The H3BO3 flux can decrease the single phase forming temperature of CaAl12O19:Mn4+ phosphors by about 150°C.

Largely enhanced piezoelectric and luminescent properties of Er doped BST ceramics

RSC Advances ◽  
2015 ◽  
Vol 5 (111) ◽  
pp. 91903-91907 ◽  
Author(s):  
Wei Li ◽  
Zhijun Xu ◽  
Ruiqing Chu ◽  
Zhihua Wu ◽  
Jigong Hao ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Luminescent Properties ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Bst Ceramics ◽  
Er Doped

Multifunctional Ba1−xTi0.96Sn0.04O3 + x mol% Er (BST-Er) ceramics were prepared using a solid state reaction method.

Influence of Flux on Morphological and Luminescent Properties of Y3Al5O12:Tb3+ Phosphor

2010 ◽  
Vol 663-665 ◽  
pp. 177-182
Author(s):  
Quan Mao Yu
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Luminescent Properties ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Morphology Characteristics

The Y3Al5O12: Tb3+ phosphors are synthesized by solid-state reaction method using fluxes of LiF, NaF, MgF2, AlF3, CaF2, SrF3, KH2PO4 and complex fluxes of LiF+AlF3, KH2PO4+LiF separately. The influence of fluxes on phosphors morphology and luminescent properties are investigated by SEM, HITACHI F-450 photometer and cathodoluminescent photometer. The results indicate that KH2PO4 can improve the morphology characteristics of the phosphors, but LiF, AlF3, NaF, MgF2, SrF3, CaF2 are unavailable. LiF, NaF, AlF3, KH2PO4 can improve the phosphors photoluminescent intensity more than 20 percent and cathodoluminescent intensity more than 10 percent. Using KH2PO4 as flux, excellent luminescent properties and well dispersed ~2 m spherical or sub-spherical YAG: Tb3+ phosphors can be synthesized under 1500 oC.

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