A NOVEL WARM RED-EMISSION OF SRLA 0.9 EU 0.1 AlO 4 PHOSPHOR OBTAINED BY COMBUSTION METHOD (original) (raw)
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Displays, 2008
Eu2+, Dy3+ and Gd3+ co-doped strontium aluminate yellow-green phosphor was synthesized by combustion method using urea as reducer at 600 °C. The crystallization, particles size and luminescence properties of the sample have been investigated. The results are as follows: Eu2+, Dy3+ and Gd3+ doped into the phosphor do not change the crystalline structure of strontium aluminate. The average size of particles is about 100 nm. The excitation and emission spectra are broad bands with the peaks at 348 and 515 nm, respectively. Compared with SrAl2O4: Eu2+, Dy3+ phosphor, the initial brightness improved and the afterglow time prolonged.
Combustion Synthesis and Luminescent Properties of Red Emitting Sr4-xAl6MoO16:xEu3+ Phosphor
International Journal of Scientific Research in Science and Technology (IJSRST), 2018
In the present work, Sr 4-x Al 6 MoO 16 :xEu 3+ (x= 2,3,4 &5 %) red-emitting phosphors have been successfully synthesized by the combustion method and their photoluminescence characterization was performed. Photoluminescence spectra showed that the emission peaks at 593 (5 D 0 → 7 F 1) and 615 nm (5 D 0 → 7 F 2) for Eu 3+ are observed after excitation at 270 nm (i.e. Mo–O charge transfer band). Intense red emission of Eu 3+ in Sr 4-x Al 6 MoO 16 host lattice show the occupation of a non-centrosymmetric site by the rare earth ions in the host lattice. The emission intensity of Eu 3+ ions in the Sr 4-x Al 6 MoO 16 host largely enhanced with the concentration increasing of activator (Eu 3+). Intense characteristic emissions show no concentration quenching up to 3 mol% concentration of rare earth ion and the emission intensity reached the maximum at x=4%. Among these phosphors, Sr 4-x Al 6 MoO 16 :xEu 3+ synthesized at 750℃ exhibits the strongest red emission and appropriate CIE chromaticity coordinates (x=0.637, y=0.359) close to the NTSC standard value. It is shown that Sr 4-x Al 6 MoO 16 :xEu 3+ phosphors are demonstrating their potential suitability for application in solid state lighting.
Scientific Reports, 2023
In the present study, the Sr 1−x Al 2 O 4 :Eu x (x = 0.00, 0.01, 0.03, 0.05, 0.07, and 0.09) phosphor were synthesized by urea fuel combustion method at 580 °C temperature with very high brightness and long after glow. The structural studies carried out using XRD technique shows that the sample is single phased in nature and it gets crystallized into monoclinic phase with standard JCPDS 34-0379 card. The oxide formation was examined using FTIR technique. UV-Visible spectroscopy has been used to study the optical band gap of material, it's value in the current case, Sr 1−x Al 2 O 4 :Eu x (x = 0.05) is 3.78 eV. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirm the formation of nano particle, with average particle size around 6-25 nm. The elemental composition was confirmed by using Energy Dispersive X-ray (EDX) technique. The photo-luminescence study revealed that it gives broad emission spectra using excitation wavelength λ ex = 365 nm. It is observed that the Sr 1−x Al 2 O 4 :Eu x (x = 0.05) phosphor give maximum emission intensity and it can be regulated as green (0.23, 0.49) emission with the colour temperature 3224 K, CRI 78, and colour purity 60.69%. The spectra are intense and lie in the visible range. The green lights can regulate the circadian rhythm through melatonin, and it is also suitable for green LED and other optoelectronic devices. The Sr 1−x Al 2 O 4 :Eu x (x = 0.00 and 0.05) phosphor behaves like eco-materials, because nano particles of Sr 1−x Al 2 O 4 :Eu x (x = 0.05) does not show antimicrobial activity. Phosphor materials are being used more widely as a durable, cost-effective source of energy on a global basis. Light-emitting diodes (LEDs) are anticipated to reduce light energy use by 15% by 2020 and 40% by 2030, totalling 3.0 quads in 2030 alone, compared to today's estimates, according to the US Department of Energy, resulting in a $26 billion energy savings 1. As a result, there would be a nearly 190 million metric tonne decrease in carbon dioxide (greenhouse gas) emissions. Luminescence, which has revolutionised everything from overhead fluorescent tubes to incandescent light bulbs, may become extinct in the coming years, according to the United States Department of Energy 2. Because of their inherent qualities, such as low energy consumption, long life, high chemical stability, and environmental friendliness, phosphors converted white light-emitting diodes and other light-emitting diodes are outstanding materials for solid lighting technology and could be used in future lighting devices 3. Due to their outstanding luminous properties, rare earth and alkaline earth aluminates phosphorescent materials have a wide range of applications in solid-state lighting, display components, and other fields. Alkaline earth aluminates make the perfect chemical host material for enhancing luminescence in today's luminescence-based technologies. The host lattice's structure affects the luminescence, which can happen anywhere in the electromagnetic spectrum from ultraviolet to infrared. The long-lived luminescence property is demonstrated by the photoluminescence of rare-earth-doped alkaline earth aluminates, MAl 2 O 4 (M = Ca, Sr, Ba) 4. The researchers have gained interest in long afterglow characteristic of rare earth-doped alkaline earth aluminates phosphors. Luminescent paint, emergency device safety indicators, electronic instrument dial pads, vehicle
Journal of Non-crystalline Solids, 2009
Strong blue-green light emitting Eu doped SrAl 2 O 4 phosphor was synthesized by a low-temperature initiated, self-propagating and gas producing combustion process in a very short time (<5 min). The prepared powder was characterized by X-ray diffraction, Fourier-transform infrared spectrometry and scanning electron microscopy. The excitation spectrum shows a peak at 397 nm. Upon excitation at 397 nm, the emission spectrum exhibits a well defined broad band with maximum at 493 nm corresponding to 4f 6 5d ? 4f 7 transition. Electron paramagnetic resonance (EPR) measurements at X-band showed low field signals due to Eu 2+ ions in SrAl 2 O 4 :Eu.
The combustion synthesis method was employed for the synthesis of red-emitting monoclinic SrAl2O4:Eu 3+ phosphors. Structural characterization of annealed samples was carried out via X-ray Diffraction (XRD). XRD patterns reveal that strontium aluminate samples were cubic spinel nanoparticles and the grain size determined by the Debye-Scherrer formula is 35.34 nm. The vibrational stretching frequencies corresponding to the composites were confirmed by FT-IR spectroscopy. The PL spectra show the strongest emission at 612 nm corresponds to the 5 D0 → 7 F2 transition of Eu 3+ , which results in bright red color emitting phosphor used for display devices and lamp industries.
International Journal of Sciences: Basic and Applied Research, 2015
We report here a single-phased Sr 3 Al 2 O 6 :Tb 3+ , Eu 3+ as a candidate for white light emitting phosphor for the application in fluorescent lamps. The Sr 3 Al 2 O 6 :Tb 3+ , Eu 3+ phosphor exhibits emission over blue, green and red region of the visible spectrum. The phosphor when excited by 254 nm shows sharp lines peaked in 400-550nm due to 5 D 3 - 7 F J transitions and 5 D 4 - 7 F J transitions of Tb 3+ ions and sharp peaks in the orange–red region (580–700 nm) originating from 5 D 0 - 7 F J transitions of Eu 3+ ions. The energy transfer phenomenon in Sr 3 Al 2 O 6 :Tb 3+ , Eu 3+ system were observed as a result of increasing concentration of europium in Sr 3 Al 2 O 6 :Tb 3+ system. Varying concentration of Tb 3+ and Eu 3+ are studied in detail for attaining the white light emission from this host lattice. The thermoluminescence study was performed on the β- irradiated Sr 3 Al 2 O 6 :Tb 3+ , Eu 3+ phosphor to study its change in trap depths due to addition of europium as co...
Effect of Al/Sr ratio on the luminescence properties of SrAl2O4:Eu2+, Dy3+ phosphors
Recent studies have brought out many phosphors like Eu 2+ , Dy 3+ -doped alkaline earth aluminates. The trivalent Dy 3+ ions as co-dopants greatly enhance the duration and intensity of persistent luminescence. These phosphors show excellent properties, such as high quantum efficiency, long persistence of phosphorescence, good stability and suitable color emission.
JOURNAL OF CHARACTERIZATION
Using the combustion method, red emitting Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors were synthesized. The properties of photoluminescence were also studied. The red (614 nm) emission from Sr4Al14O25:Eu 3+ phosphor, at excitation 394 nm. The excitation peak was around 404 nm and was attributed to 6 H5/2→ 4 F7/2, while the emission spectrum had emission peaks at 565 nm and 603 nm for Sr4Al14O25:Sm 3+ phosphor. Furthermore, the chromaticity coordinates of Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors were found in the red region (0.677, 0.322) and (0.640, 0.359) by the Commission International de l'Eclairage respectively. According to the current findings, Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors can be used as a red emitting phosphor in near-ultraviolet (n-UV) based w-LEDs.
Journal of Characterization, 2022
Using the combustion method, red emitting Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors were synthesized. The properties of photoluminescence were also studied. The red (614 nm) emission from Sr4Al14O25:Eu 3+ phosphor, at excitation 394 nm. The excitation peak was around 404 nm and was attributed to 6 H5/2→ 4 F7/2, while the emission spectrum had emission peaks at 565 nm and 603 nm for Sr4Al14O25:Sm 3+ phosphor. Furthermore, the chromaticity coordinates of Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors were found in the red region (0.677, 0.322) and (0.640, 0.359) by the Commission International de l'Eclairage respectively. According to the current findings, Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors can be used as a red emitting phosphor in near-ultraviolet (n-UV) based w-LEDs.
Synthesis and Photoluminescence Properties of Red Emitting SrLiB9O15:Eu 3+ Phosphor
isara solutions, 2022
A series of Sr(1-x) LiB9O15:xEu 3+ (x= 0.01, 0.03, 0.05, and 0.07 mole) red emitting phosphors have been successfully synthesized by combustion method and characterized by photoluminescence (PL). The luminescence properties of all Eu 3+-doped samples were investigated by excitation and emission spectra. The excitation spectra of SrLiB9O15:Eu 3+ phosphors show characteristic peak at 395 nm in addition to other characteristic peaks of Eu 3+ under emission at 615 nm. The emission spectra of Eu 3+-doped samples indicated most intensive red emission band dominated at 615 nm belonging to 5 D0→ 7 F2 electric dipole transition. Furthermore, the optimum or quenching concentration of Eu 3+ ion has been determined as x = 0.05 showed the maximum emission intensity when it was excited at 395 nm.