Synthesis of narrow-band red-emitting SrLiAl3N4:Eu2+ phosphor and the study of its influencing factors on luminescence performance

2021 ◽  
pp. 2151035
Author(s):  
Yuxiao Yang ◽  
Zicheng Lu ◽  
Yiheng Liu ◽  
Chen Wang ◽  
Bing Yan ◽  
...  
Keyword(s):  
Calcination Temperature ◽  
Luminescence Intensity ◽  
Doping Concentration ◽  
Narrow Band ◽  
Red Light ◽  
Emission Peak ◽  
Doping Amount ◽  
Solid State Method ◽  
White Leds ◽  
Luminescence Performance

In this paper, safer raw materials were used to synthesize SrLiA13N4:Eu[Formula: see text] phosphors under high purity nitrogen gas by high-temperature solid-state method, and the effects of activator doping concentration, calcination temperature, calcination time and matrix lattice cation substitution on their luminescence performance were studied. All the samples can emit red light effectively excited by ultraviolet or blue light, and the narrow-band red emission peak is at [Formula: see text]651 nm. Energy Dispersive Spectroscopy (EDS) results show that the Eu[Formula: see text]element has been successfully doped and uniformly distributed. The X-ray powder diffraction (XRD) pattern showed that impurities of AlN and SrO were present in the synthesized samples, and the impurity phase was significantly reduced or eliminated with the increase of calcination temperature. The relationship between luminescence intensity of phosphor and Eu[Formula: see text] doping concentration indicates that with the increase of Eu[Formula: see text] doping concentration, the luminescence intensity of powder first increases and then decreases, and the optimal doping concentration is 0.02. Concentration quenching will occur if the doping amount of Eu[Formula: see text] continues to increase. The addition of Ca makes it replace Sr in the crystal lattice, resulting in the reduction of field force in the lattice expansion crystal, resulting in the reduction of luminescence intensity, the red shift of emission peak, and the increase of half height and width. The results exhibit that SrLiAl3N4:Eu[Formula: see text] may be a more suitable phosphor than CaLiAl3N4:Eu[Formula: see text] as a narrow-band red component in white LEDs.

Systematic investigation of Eu3+ activated Na2Ln4(MoO4)7 [Ln = La, Gd and Y] narrow band red emitting phosphors for hybrid white LEDs and plant growth

2020 ◽  
Vol 44 (35) ◽  
pp. 14823-14836 ◽  
Author(s):  
Marikumar Rajendran ◽  
Sivakumar Vaidyanathan
Keyword(s):  
Solid State ◽  
Plant Growth ◽  
Narrow Band ◽  
Systematic Investigation ◽  
Solid State Method ◽  
White Leds ◽  
Red Phosphors ◽  
Conventional Solid State Method ◽  
State Method

A sequence of Eu3+ activated Na2Ln4(MoO4)7 [Ln = La, Gd and Y] red phosphors has been synthesized using a conventional solid-state method.

Optical Properties of CaYAlO4: Eu3+ Phosphors

2011 ◽  
Vol 222 ◽  
pp. 231-234 ◽  
Author(s):  
Marilena Bartic ◽  
Hiroko Kominami ◽  
Yoichiro Nakanishi ◽  
Kazuhiko Hara
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Powder Diffraction ◽  
Doping Concentration ◽  
Synthesis Temperature ◽  
Emission Peak ◽  
Solid State Method ◽  
X Ray ◽  
Main Emission Peak ◽  
State Method

CaYAlO4:Eu3+ phosphors have been synthesized by a solid state method, and characterized by X-ray powder diffraction and photoluminescence (PL). Under the excitation of 147 nm, the synthesized phosphors indicated PL characteristics of the Eu3+ center with the main emission peak at a wavelength of 611.5 nm. The emission intensity depended on synthesis temperature and Eu3+ doping concentration. The highest PL intensity was found for the Ca0.97Eu0.03YAlO4 synthesized at 1400°C for 2 h.

Effects of Charge Compensators on Structure and Luminescent Properties of Microwave Synthesized CaMoO4:Eu3+ Red Phosphors

2017 ◽  
Vol 727 ◽  
pp. 592-597
Author(s):  
Ying Han ◽  
Zhi Lin Li ◽  
Wan Zhang ◽  
Yan Jie Yin ◽  
Yan Mei Li ◽  
...  
Keyword(s):  
Broad Band ◽  
Luminescent Properties ◽  
Emission Peak ◽  
Luminous Intensity ◽  
Main Peak ◽  
Doping Amount ◽  
X Ray ◽  
Red Phosphors ◽  
Charge Compensator ◽  
Pure Phase

Red phosphors CaMoO4:Eu3+ were synthesized by microwave method with MnO2 as microwave absorbent. The phase structure and luminescent properties of the as-synthesized phosphors were investigated by X-ray powder diffraction and Fluorescence spectrophotometer. The results show that when the reaction time was 40 min, microwave power was medium-high fire (~560 W), we got the tetragonal CaMoO4:Eu3+ pure phase. The excitation spectrum of CaMoO4:Eu3+ was composed by a broad band between 200 nm and 350 nm and a series of peaks from 350 nm to 500 nm. The main peak was at 305 nm. The emission spectrum was composed of a series of peaks in the range of 550~750 nm and the main peak was at 617 nm due to the 5D0→7F2 transition of Eu3+. Doping charge compensator Li+, Na+ or K+ could improve the luminous intensity of the sample. When the doping amount of Li+, Na+ or K+ were 8 mol%, the luminous intensity of the sample reached the maximum. The intensity of the emission peak at 617 nm was 4.04, 3.42, 3.48 times of sample without doping charge compensator.

scholarly journals Structure, Defects and Microwave Dielectric Properties of Al-doped and Al/Nd Co-doped Ba4Nd9.33Ti18O54 Ceramics

2021 ◽  
Author(s):  
Weijia Guo ◽  
Zhiyu Ma ◽  
Yu Luo ◽  
Yugu Chen ◽  
Zhenxing Yue ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Resonant Frequency ◽  
Microwave Dielectric Properties ◽  
Relative Dielectric Constant ◽  
Doping Amount ◽  
Solid State Method ◽  
Depolarization Current ◽  
Structure Defects ◽  
Microwave Dielectric ◽  
Co Doped

Abstract Ba4Nd9.33Ti18-zAl4z/3O54 (BNT-A, 0 ≤ z ≤ 2) and Ba4Nd9.33+z/3Ti18-zAlzO54 (BNT-AN, 0 ≤ z ≤ 2) ceramics were prepared by solid state method, and the effects of the two doping methods on microwave dielectric properties were compared. As the doping amount z increased, the relative dielectric constant (εr) and the temperature coefficient of resonant frequency (τf) values of the ceramics decreased, and the quality factor (Q, usually expressed by Q×f, where f is the resonant frequency) of the ceramics obviously increased when z ≤ 1.5. With the same z value, the εr and Q×f values of Al/Nd co-doped ceramics are both higher than those of Al-doped ceramics. Rietveld refinement, Raman spectroscopy and thermally stimulated depolarization current (TSDC) technique were applied to clarify the relationship among the structure, defects and microwave dielectric properties. It is shown that the Q×f values of those ceramics were closely related to the strength of the A-site cation vibration and the concentration of oxygen vacancies (B). Excellent microwave dielectric properties of εr = 72.2, Q×f = 16480 GHz, and τf = +14.3 ppm/℃ were achieved in BNT-AN ceramics with z = 1.25.

Enhanced Photoluminescence of YInGe2O7:Eu3+,Li+ Phosphor Prepared Using the Solid-State Method

2013 ◽  
Vol 684 ◽  
pp. 274-278
Author(s):  
Huang Yu Chen ◽  
Ru Yuan Yang ◽  
Shoou Jinn Chang
Keyword(s):  
Solid State ◽  
Red Light ◽  
Broad Band ◽  
Lithium Carbonate ◽  
Ion Concentration ◽  
Photoluminescence Intensity ◽  
Photoluminescence Properties ◽  
Solid State Method ◽  
Enhanced Photoluminescence ◽  
Transfer State

A Eu3+ activated YInGe2O7phosphor was synthesized by solid-state reaction and lithium carbonate was added to change the morphology and photoluminescence properties. Scanning electron microscopy showed large particle size and necking shape were obtained as the concentrations of Li+ ions increase. In the PL studies, the excitation spectrum of YInGe2O7:Eu3+ phosphors exhibited a broad band in the UV region centered at about 272 nm attributed to charge transfer state (CTS) band, which has a little shift after Li+ ion was added. As the Li+ ion concentration increased, the photoluminescence intensity of the red emission at 620 nm of Eu3+ ions was enhanced, and the optimized concentration of of added Li+ ion is 0.05. The results showed that addition of Li+ ion allows YInGe2O7:Eu3+ phosphors emitting relatively pure red light.

Growth and Light Properties of Fluorescent SiC for White LEDs

2012 ◽  
Vol 717-720 ◽  
pp. 87-92
Author(s):  
Mikael Syväjärvi ◽  
Rositza Yakimova ◽  
Motoaki Iwaya ◽  
Tetsuya Takeuchi ◽  
Isamu Akasaki ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
White Light ◽  
Energy Savings ◽  
Red Light ◽  
Visible Range ◽  
White Led ◽  
Light Emitting ◽  
Blue Led ◽  
White Leds ◽  
New Type

The LED technology started to developed many years ago with red light emitting diodes. To achieve the blue LED, novel growth technologies and process steps were explored, and made it possible to demonstrate efficient blue LED performance from nitrides. The efficiency was further developed and blue LEDs were commercially introduced in the 1990’s. The white LED became possible by the use of the blue LED and a phosphor that converts a part of the blue light to other colors in the visible range to combine into white light. However, even today there are limitations in the phosphor-based white LED technology, in particular for general lighting, and new solutions should be explored to speed the pace when white LEDs will be able to make substantial energy savings. In this paper we overview gallium nitride materials evolution and growth concepts for LEDs. We describe the fluorescent silicon carbide material prepared by a novel growth technology for a new type of white LED in general lighting with pure white light. This paper introduces an interesting research in fundamental growth and optical properties of light emitting silicon carbide.

Synthesis, photoluminescence and Judd–Ofelt analysis of red LiGd5P2O13 : Eu3+ phosphors for white LEDs

RSC Advances ◽  
2015 ◽  
Vol 5 (67) ◽  
pp. 54622-54628 ◽  
Author(s):  
Xinguo Zhang ◽  
Liya Zhou ◽  
Qi Pang ◽  
Menglian Gong
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Quantum Yield ◽  
Solid State Reaction ◽  
Red Light ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
White Leds ◽  
Good Thermal Stability ◽  
Red Phosphors

LiGd5P2O13 : Eu3+ red phosphors were prepared by solid-state reaction method. Phosphors could be efficiently excited by NUV/blue light and emit pure-red light. LiGd5P2O13 : Eu3+ shows good thermal stability with quantum yield of 46.5%.

Improvement the thermal stability of bluish-cyan emitting phosphor Y2MgAl4SiO12:Eu2+ using substitution cations (Zn, Ca, Sr) for white LEDs

CrystEngComm ◽  
2021 ◽  
Author(s):  
Huifang Yang ◽  
Panlai Li ◽  
Zejun Ye ◽  
Xiaoxue Huo ◽  
Yu Wang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Solid State Method ◽  
White Leds ◽  
State Method ◽  
Thermal Stability Of

A series of bluish-cyan color adjustable phosphors Y2MgAl4SiO12:xEu2+(YMAS) and Y2(Mg1-y,My)Al4SiO12:Eu2+ (M=Zn, Ca, Sr) were synthesized by the solid-state method. The thermal stability can be improved by modifying cation, especially, the...

Synthesis and Characterization of Lightweight Beryllium Chloro Silicate Phosphor

2022 ◽  
pp. 89-100
Author(s):  
Khushbu Sharma
Keyword(s):  
Blue Emission ◽  
Emission Peak ◽  
Excitation Band ◽  
Photoluminescence Spectra ◽  
Strong Emission ◽  
White Leds ◽  
Long Afterglow ◽  
Silicate Phosphor ◽  
Low Weight

In this chapter, low weight barium-based cholorsilicate Ba5Cl6Si2O6:Eu2+ is prepared through a solid-state reaction. To confirm the structure of the synthesized phosphors, powder photographs were obtained using an x-ray diffractometer. Photoluminescence spectra and FTIR spectra were recorded. Photoluminescence spectra are studied. The emission peak is observed at 407 nm at excitation 275 nm. The intense violet-blue emission is obtained. The broad excitation band and strong emission indicate that Ba5Cl6Si2O6:Eu2+could be a good phosphor candidate for blue LED and white LEDs. Decay curve indicates the phosphor has a long afterglow feature.

Taguchi method-assisted optimization of multiple effects on the optical and luminescence performance of Ce:YAG transparent ceramics for high power white LEDs

2019 ◽  
Vol 7 (37) ◽  
pp. 11431-11440 ◽  
Author(s):  
Le Zhang ◽  
Qing Yao ◽  
Yuelong Ma ◽  
Bingheng Sun ◽  
Cen Shao ◽  
...  
Keyword(s):  
Taguchi Method ◽  
Thermal Performance ◽  
High Power ◽  
Transparent Ceramics ◽  
Packaging Technology ◽  
White Leds ◽  
Luminescence Performance

Ce:YAG transparent ceramics have great potential in white LEDs, especially under high power packaging technology, due to their superior thermal performance.

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