scholarly journals Synthesis and Luminescence Properties of SrGd2O4:Eu3+ Red Phosphors

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Jun-Feng Wang ◽  
Hao Zu ◽  
Chuan-Wen Lin ◽  
Shou-Jun Ding ◽  
Peng-Yu Shao ◽  
...  
Keyword(s):  
Solid Phase ◽  
Raw Materials ◽  
Red Light ◽  
Luminescence Properties ◽  
Phase Method ◽  
Excitation Spectra ◽  
Phosphor Material ◽  
Red Phosphor ◽  
Red Phosphors ◽  
Near Ultraviolet

As one of the important raw materials for LED products, phosphors play an important role. At present, the spectrum of LED phosphors lacks red light, resulting in poor quality of white LED products and a low color rendering index (Ra <80), which affects lighting effects. To solve this problem, we synthesized the SrGd2O4:Eu3+ red phosphor by a high-temperature solid-phase method. The structure and luminescence properties of SrGd2O4:Eu3+ red phosphors were studied by means of X-ray diffraction (XRD) measurements of their emission and excitation spectra, and their spectra were analyzed. We also studied the Eu3+ doping concentration with the best luminous efficiency and the color coordinate of the SrGd2O4:Eu3+ phosphor. The experimental results show that SrGd2O4:Eu3+ is a new red phosphor material that can be used for near-ultraviolet or blue-light excitation and has good practicability.

A novel orange-red phosphor Ca3B2O6:Sm3+, A+(A = Li, Na, K) for white light emitting diodes

2014 ◽  
Vol 07 (03) ◽  
pp. 1450033 ◽  
Author(s):  
Qingbo Liu ◽  
Yufeng Liu ◽  
Fu Yang ◽  
Bing Han ◽  
Hao Feng ◽  
...  
Keyword(s):  
Emission Spectrum ◽  
Integral Intensity ◽  
Red Light ◽  
Red Phosphor ◽  
Light Emitting ◽  
Red Phosphors ◽  
Near Ultraviolet ◽  
Bright Orange ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

A novel orange-red phosphor Ca 3 B 2 O 6: Sm 3+, A+( A = Li , Na , K ) has been synthesized by solid-state reaction at 950°C. The phase purity and photoluminescence (PL) behavior of the phosphor are studied in detail using the powder X-ray diffraction (XRD) technique and PL measurements. Ca 3 B 2 O 6: Sm 3+ phosphor can be efficiently excited by near ultraviolet (n-UV) and blue light, and the emission spectrum consists of four emission peaks at 563, 599, 646 and 709 nm, generating bright orange-red light. When a cation A+ is introduced into Ca 3 B 2 O 6: Sm 3+ as charge compensator, the emission intensity of Ca 3 B 2 O 6: Sm 3+ is evidently enhanced, but the PL spectral profile is unchanged. The integral intensity of the emission spectrum of Ca 2.96 Sm 0.02 Na 0.02 B 2 O 6 excited at 401 nm is about 1.2 times than that of Y 2 O 2 S : Eu 3+ commercial red phosphor. The CIE chromaticity coordinates of Ca 2.96 Sm 0.02 Na 0.02 B 2 O 6 phosphor were (0.608, 0.365), which are close to that of the commercial red phosphors Y 2 O 3: Eu 3+ (0.655, 0.345), Y 2 O 2 S : Eu 3+ (0.622, 0.351) and Sr 2 Si 5 N 8: Eu 2+ (0.620, 0.370).

Preparation of YVO4:Eu3+ Red Phosphor by Combustion Synthesis and its Luminescence Properties

2010 ◽  
Vol 663-665 ◽  
pp. 45-49
Author(s):  
Zhen Hua Liang ◽  
Feng Qi Lu ◽  
Xiao Xia Liu ◽  
Gui Hua Peng
Keyword(s):  
Combustion Synthesis ◽  
Raw Materials ◽  
Red Light ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Post Heat Treatment ◽  
Red Phosphor ◽  
X Ray ◽  
Metal Nitrates ◽  
Ultraviolet Light Irradiation

YVO4:Eu3+ red phosphor was prepared by combustion synthesis without any post heat treatment at 700 oC-900 oC, using urea, oxalate acid and metal nitrates as raw materials. The product can emit bright red light under ultraviolet light irradiation. The phase compositions and luminescence properties were studied via X-ray diffraction (XRD) and photoluminescence spectra. The experimental results indicated that addition of appropriate amount of fuel and oxalate acid is favorable for the improvement of luminescence intensity.

Red-Emitting Phosphor Ca2MgSi2O7: Sm3+, Eu3+ for UV White Light-Emitting Diodes

2021 ◽  
Author(s):  
Ayinuremu Tuerxun ◽  
Subiyinuer Jilili ◽  
Lei Wang ◽  
Aierken Sidike
Keyword(s):  
Energy Transfer ◽  
White Light ◽  
Light Emission ◽  
Solid Phase ◽  
Red Light ◽  
Critical Distance ◽  
Color Temperature ◽  
Phase Method ◽  
Excitation Peak ◽  
Red Phosphors

Abstract In this research, a series of Ca2MgSi2O7: 2% Sm3+, x% Eu3+ (x=4, 5, 6, 7, 8) red phosphors were synthesized using the high-temperature solid-phase method. The phase and luminescence properties of the samples were investigated using an X-ray diffractometer and a photoluminescence spectrometer. The results showed that the synthesized samples were of pure phase, and the introduction of small amounts of Sm3+ and Eu3+ had no significant impact on the crystal structure of the phosphors. It is observed from the phosphor spectra that the co-doped samples exhibited intense red-light emission corresponding to that of Eu3+ at 613 nm when excited at the strongest excitation peak of Sm3+ (401 nm); here, the emission peak intensity of Eu3+ increased by a factor of 5.3. It is found that resonant nonradiative energy transfer occurs from Sm3+ to Eu3+ in the sample, and the energy transfer efficiency reaches up to 44%. The calculated critical distance for energy transfer is 16.117 Å and the concentration interrupt mechanism is an electric dipole-dipole (d-d) interaction. The color coordinates of the samples are all located in the red region (0.6319, 0.3676) with a color purity of ~ 89.3%. The samples exhibited thermal stability of up to 68.6% of that at room temperature when heated to 150˚C . The LED samples packaged with the phosphors emitted warm white-light with a color temperature (CCT) of 5553 K and a color rendering index (Ra) of 84.8. The magnesium yellow feldspar silicate phosphor is suitable as the red component in white LED trichromatic phosphors and has potential applications in solid-state lighting.

scholarly journals Fe3O4@C Nanoparticles Synthesized by In Situ Solid-Phase Method for Removal of Methylene Blue

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 330
Author(s):  
Hengli Xiang ◽  
Genkuan Ren ◽  
Yanjun Zhong ◽  
Dehua Xu ◽  
Zhiye Zhang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Solid Phase ◽  
Raw Materials ◽  
Phase Method ◽  
Maximum Adsorption Capacity ◽  
High Catalytic Activity ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
High Concentrations

Fe3O4@C nanoparticles were prepared by an in situ, solid-phase reaction, without any precursor, using FeSO4, FeS2, and PVP K30 as raw materials. The nanoparticles were utilized to decolorize high concentrations methylene blue (MB). The results indicated that the maximum adsorption capacity of the Fe3O4@C nanoparticles was 18.52 mg/g, and that the adsorption process was exothermic. Additionally, by employing H2O2 as the initiator of a Fenton-like reaction, the removal efficiency of 100 mg/L MB reached ~99% with Fe3O4@C nanoparticles, while that of MB was only ~34% using pure Fe3O4 nanoparticles. The mechanism of H2O2 activated on the Fe3O4@C nanoparticles and the possible degradation pathways of MB are discussed. The Fe3O4@C nanoparticles retained high catalytic activity after five usage cycles. This work describes a facile method for producing Fe3O4@C nanoparticles with excellent catalytic reactivity, and therefore, represents a promising approach for the industrial production of Fe3O4@C nanoparticles for the treatment of high concentrations of dyes in wastewater.

Synthesis and luminescence properties of red-emitting K2MgSiO4:Eu3+ phosphors

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744058
Author(s):  
Rong Yang ◽  
Huidong Tang
Keyword(s):  
Decay Curve ◽  
Emission Spectra ◽  
Solid State Reaction Method ◽  
Excitation Spectra ◽  
Red Phosphor ◽  
Light Emitting ◽  
X Ray ◽  
Dipole Interactions ◽  
Near Ultraviolet ◽  
White Light Emitting Diodes

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.

Research on Electrochemical Properties of LiMnPO4 Synthesized by High Temperature Solid-Phase Method

2012 ◽  
Vol 487 ◽  
pp. 714-718 ◽  
Author(s):  
Sheng Kui Zhong ◽  
Ying Mei Zhang ◽  
Wei Li ◽  
Yue Bin Xu
Keyword(s):  
High Temperature ◽  
Solid Phase ◽  
Raw Materials ◽  
Particle Surface ◽  
Lithium Ion ◽  
Xrd Analysis ◽  
Spherical Particles ◽  
Phase Method ◽  
Solid Phase Method ◽  
Olivine Structure

LiMnPO4cathode material for lithium ion batteries was synthesized by high temperature solid-phase method using MnCO3, Li2CO3, NH4H2PO4as raw materials. The structure of samples was identified by XRD analysis and the particle surface morphology was examined by SEM. The results of XRD showed that the LiMnPO4sample sintered at 700°C for 20h had single ordered olivine structure. The SEM pattern showed that spherical particles distributed uniformly. Respectively, it figured out that the initial charge and discharge capacities of the samples at 0.05C rate were 133.9 and 66.4mAh•g-1.

scholarly journals Effect of Waste Glass Powder on Phase, Microstructure and Mechanical Properties of Mullite Based Porous Ceramics with Coal-series Solid Waste as Raw Materials

2020 ◽  
Author(s):  
Wei Lian ◽  
Yan Liu ◽  
Wenjie Wang ◽  
Yangtao Dong ◽  
Sheng Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Powder ◽  
Solid Phase ◽  
Raw Materials ◽  
Porous Ceramics ◽  
Volume Density ◽  
Synthesis Temperature ◽  
Phase Method ◽  
Microstructure And Mechanical Properties ◽  
Solid Phase Method

Abstract Mullite based porous ceramics were successfully prepared by using a solid-phase method with gangue, slime and sawdust as raw materials. The effects of the content of glass powder and calcining temperature on microstructure and mechanical properties of the samples were systematically studied. It is found that glass powder can prevent the formation of Kyanite and reduce the synthesis temperature of mullite. The samples with 4% glass powder have a large amount of mullite calcined at 1150°C for 3h. Meanwhile, alumina in the sample is completely converted into mullite at 1180°C for 3h. Mullite content reaches 64.2wt%. The minimum apparent porosity is 31.22%, while the maximum volume density and diameter shrinkage are 1.74g/cm 3 and 8.48%, respectively. The ratio of pores of <8μm to those of 8~20μm is varied from 7:2 to 2:7, due to the addition of the glass powder. With increasing content of mullite, the flexural properties of the samples are increased from 7.7MPa to 28.36MPa. Therefore, with solid wastes as the resource, the porous ceramics have a bright prospect.

scholarly journals Structural and luminescent characteristic of Sm3+ doped magnesium sulfide borate red phosphor for white LED

2017 ◽  
Vol 13 (4) ◽  
pp. 807-811
Author(s):  
Saddiq Abubakar Dalhatu ◽  
Rosli Hussin ◽  
Karim Deraman ◽  
Bulus Ibrahim ◽  
Yamusa Abdullahi ◽  
...  
Keyword(s):  
Red Light ◽  
Spectral Studies ◽  
White Led ◽  
Excitation Spectra ◽  
Structural Units ◽  
Red Phosphor ◽  
Red Led ◽  
Raman Spectral ◽  
Ir And Raman ◽  
Magnesium Sulfide

Polycrystalline compositions based on MgO, SO3 and B2O3 have both scientific and technological importance because of their useful applications. Doping with rare earth elements not only due to a rearrangement in the structure, but also to variation in the luminescence properties. Magnesium sulfide borate doped samarium oxide (MgSBO3:Sm3+) phosphors were prepared by solid state reaction and their structural and luminescence characteristic were studied and reported. IR and Raman spectral studies have been made to explore the presence of functional groups and various structural units in the prepared Polycrystalline. The formation of SO4, BO4, BO3, B-O-B and S-O-B structural units have been investigated. The emission and excitation properties were studied. And the results show that the emission and excitation spectra of these phosphors can be excited by ultraviolet (UV) 341, 370 and 409 nm light, and emit green, yellow and red light with intense peak at 601 nm, which are nicely in accordance with the widely applied near- UV LED chip. The emission intensities of these phosphors were increased with increases doping concentration. Therefore, these phosphors are the promising luminescent material towards white red LED applications.

Hydrothermal Synthesis and Size-Enhanced Chromaticity of Sr2ZnSi2O7:Eu3+ Nanoparticles

2008 ◽  
Vol 8 (3) ◽  
pp. 1449-1453 ◽  
Author(s):  
Junxi Wan ◽  
Youwei Yao ◽  
Guoyi Tang ◽  
Yitai Qian
Keyword(s):  
Bulk Material ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Blue Shift ◽  
Average Diameter ◽  
Hydrothermal Route ◽  
Excitation Spectra ◽  
Red Phosphor ◽  
Red Phosphors ◽  
20 Nm

Red phosphor Sr2ZnSi2O7:Eu3+ nanoparticles with an average diameter of 20 nm were successfully synthesized via a low-temperature hydrothermal route in order to understand the underlying relationship between size and luminescent properties. The nanometer-sized particles result in a distinct improvement in chromaticity and a high quenching concentration. According to emission spectra, the relative intensity of the 5D0 → 7F2 to 5D0 → 7F1 transitions in nanometer-sized phosphors is higher than that of the corresponding bulk material. The better chromaticity results from the more distorted lattices and relatively lower crystal symmetry around the Eu3+ ions, which is ascribed to the large surface area due to the nanometer size of the phosphor. Moreover, the nanometer-sized Sr2ZnSi2O7:Eu3+ red phosphor exhibits a shorter fluorescent lifetime and a blue-shift in excitation spectra compared to that of its bulk counterpart. These results indicate that size-induced enhancement of luminescent properties is an efficient way to obtain red phosphors with better chromaticity.

Research on Grafted Chitosan in Heterogeneous System

2011 ◽  
Vol 239-242 ◽  
pp. 3275-3278
Author(s):  
Juan Qin Xue ◽  
Dan Dan Wen ◽  
Wei Bo Mao ◽  
Yun Feng Xue ◽  
Ye Wei Du
Keyword(s):  
Reaction Time ◽  
Solid Phase ◽  
Raw Materials ◽  
Sodium Thiosulfate ◽  
Ammonium Molybdate ◽  
Phase Method ◽  
Cobalt Metal ◽  
Experimental Conditions ◽  
Metallic Salt ◽  
Solid Phase Method

With phthalic anhydride, urea, metallic salt and ammonium molybdate as raw materials, Cobalt metal phthalocyanines is prepared by solid-phase method, and the cobalt metal phthalocyanine is modified by the shun dl-aspartic acid anhydride. In the homogeneous conditions, the effects of the reaction temperature, the reaction time, phthalocyanine dosage and initiator dosage are studied. The experimental results show that the grafting polymerization products with the highest grafted rate can be prepared under the optimal experimental conditions, which are found to be 60°C for the temperature, 3h for the reaction time, 0.08g for the potassium persulfate and sodium thiosulfate. The product is analyzed by means of IR, the results show that the chitosan is grafted successfully, and the reaction may occurs on the amino and the hydroxyl of chitosan.

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