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1.
Eu3+‐doped polystyrene and polyvinylidene fluoride nanofibers made by electrospinning for photoluminescent fabric designing
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Sangeeta Gopichandra Itankar Manjusha Prafulla Dandekar Subhash Baburao Kondawar Bhaskar Marotrao Bahirwar 《Luminescence》2017,32(8):1535-1540
Eu3+‐doped polystyrene and polyvinylidene fluoride (PVDF/Eu3+ and PS/Eu3+) nanofibers were made using electrospinning. These fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT‐IR), energy dispersive spectroscopy (EDX) and photoluminescence (PL). Spectral analysis of PVDF/Eu3+ and PS/Eu3+ nanofibers was based on their emission spectra. A bright red emission was noticed from Eu3+ that was assigned to the hypersensitive 5D0 → 7F2 transition. The enhanced intensity ratios of 5D0 → 7F2 to 5D0 → 7F1 transitions in the nanofibers indicated a more polarized chemical environment for the Eu3+ ions and greater hypersensitivity for the 5D0 → 7F2 transition, which showed the potential for application in various polymer optoelectronic devices. The Eu3+‐doped polymer (PVDF/Eu3+ and PS/Eu3+) nanofibers are suitable for the photoluminescent white light fabric design of smart textiles. This paper focuses on the potential application of smart fabrics to address challenges in human life. 相似文献
2.
A series of Eu3+‐activated NaLi2PO4 novel phosphors was synthesized by the solid‐state reaction method. The X‐ray diffraction (XRD) and photoluminescence (PL) properties of these phosphors were investigated at room temperature. The excitation spectra indicate that these phosphors can be effectively excited by near‐UV (370–410 nm) light. The emission spectra exhibit strong reddish‐orange performance, which is due to the 5D0 → 7FJ transitions of Eu3+ ions. The orange emission from transition 5D0 → 7F1 is dominant over that of 5D0 → 7F2. The concentration quenching of Eu3+ was observed in NaLi2PO4:Eu3+ when the Eu concentration was at 1 mol%. The impact of doping Eu3+ and photoluminescence properties were investigated and we propose a feasible interpretation. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
3.
This study synthesized BaMoO4:Eu3+ red phosphors using the microwave method. In addition, the phase composition, morphology, and luminescence properties of the red phosphors were characterized using X-ray diffraction, field-scanning electron microscopy, and photoluminescence spectroscopy. The results revealed that doping red phosphors with different concentrations of Eu3+ does not change the crystal structure of the matrix material. The BaMoO4:Eu3+ phosphors exhibited micron-scale irregular polyhedra, which could be excited by ultraviolet light with a wavelength of 395 nm to induce red-light emission. The optimal dosage of Eu3+ was 0.08, and the chromaticity coordinates of BaMoO4:0.08Eu3+ phosphors were (0.5869, 0.3099). White light-emitting diode (w-LED) devices manufactured by using a combination of BaMoO4:0.08Eu3+ phosphor and commercially available phosphors exhibited good white-light emission under the excitation of an ultraviolet chip. The BaMoO4:0.08Eu3+ red phosphors that rapidly synthesized under the microwave field are expected to be used in w-LED devices. 相似文献
4.
Rare‐earth ions play an important role in eco‐friendly solid‐state lighting for the lighting industry. In the present study we were interested in Eu3+ ion‐doped inorganic phosphors for near ultraviolet (UV) excited light‐emitting diode (LED) applications. Eu3+ ion‐activated SrYAl3O7 phosphors were prepared using a solution combustion route at 550°C. Photoluminescence characterization of SrYAl3O7:Eu3+ phosphors showed a 612 nm emission peak in the red region of the spectrum due to the 5D0→7F2 transition of Eu3+ ions under excitation at 395 nm in the near‐UV region and at the 466 nm blue excitation wavelength. These red and blue emissions are supported for white light generation for LED lighting. Structure, bonding between each element of the sample and morphology of the sample were analysed using X‐ray diffraction (XRD) and scanning electron microscopy (SEM), which showed that the samples were crystallized in a well known structure. The phosphor was irradiated with a 60Co‐γ (gamma) source at a dose rate of 7.2 kGy/h. Thermoluminescence (TL) studies of these Eu3+‐doped SrYAl3O7 phosphors were performed using a Nucleonix TL 1009I TL reader. Trapping parameters of this phosphor such as activation energy (E), order of kinetics (b) and frequency factor (s) were calculated using Chen's peak shape method, the initial rise method and Ilich's method. 相似文献
5.
Synthesis,PL characterizations and concentration quenching effect in Dy3+ and Eu3+ activated LiCaBO3 phosphor
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LiCaBO3:Dy3+/Eu3+ phosphors were synthesized by a solid‐state reaction. The synthesized materials were characterized using powder X‐ray diffraction pattern (XRD) for confirmation. All the structural parameters were calculated from the XRD data. Scanning electron microscopy (SEM) images showed rod‐like morphology. Photoluminescence (PL) emission spectra showed two emissions (484 and 577 nm) in Dy3+‐doped LiCaBO3:Dy3+phosphors with the concentration quenching effect and the critical distance was calculated to be about 22.76 Å. LiCaBO3:Eu3+ phosphor was effectively excited by a near‐UV light of 392 nm. The emission spectra exhibited the transition from 5D0 level to 7FJ (J = 0–2) with main emission at 614 nm, which comes from the electrodipole transition because of the asymmetric point group. The quenching concentration of Eu3+ is about 0.2 mol%, and the critical distance was calculated to be about 38.93 Å. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
6.
In this paper, we have reported the photoluminescence (PL) properties of the Ba2Mg(PO4)2:Eu3+ phosphor synthesized using a wet chemical method. The preliminary scanning electron microscopy (SEM) investigation of the sample revealed irregular surface morphology with particle sizes in the 10–50 μm range. The strongest PL excitation peak was observed at 396 nm. The emission spectra indicated that this phosphor can be effectively excited by the 396 nm wavelength. Upon 396 nm excitation, the emission spectrum showed characteristics peaks located at 592 nm and 615 nm. These intense orange‐red emission peaks were obtained due to f→f transitions of Eu3+ ions. The emission peak at 592 nm is referred to as the magnetic dipole 5D0→7F1 transition and the emission peak at 615 nm corresponded to the electric dipole 5D0→7F2 transition of Eu3+. The Commission Internationale de l’Eclairage (CIE) coordinates of the Ba2Mg(PO4)2:Eu3+ phosphor were found to be (0.586, 0.412) for wavelength 592 nm and (0.680, 0.319) for wavelength 615 nm situated at the edge of the CIE diagram, indicating high colour purity of phosphors. Due to the high emission intensity and a good excitation profile, Eu3+‐doped Ba2Mg(PO4)2 phosphor may be a promising orange‐red phosphor candidate for solid‐state lighting applications. 相似文献
7.
Junjun Zhang Linlin Li Wenwen Zi Lianchun Zou Shucai Gan Guijuan Ji 《Luminescence》2015,30(3):280-289
Almost monodisperse three‐dimensional (3D) BaMoO4, BaMoO4:Eu3+ micron‐octahedrons and micron‐flowers were successfully prepared via a large‐scale and facile sonochemical route without using any catalysts or templates. X‐Ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), energy dispersion X‐ray (EDS), Fourier transform infrared (FTIR) and photoluminescence (PL) spectroscopy were employed to characterize the as‐obtained products. It was found that size modulation could be easily realized by changing the concentrations of reactants and the pH value of precursors. The formation mechanism for micron‐octahedrons and micron‐flowers was proposed on the basis of time‐dependent experiments. Using excitation wavelengths of 396 or 466 nm for BaMoO4:Eu3+ phosphors, an intense emission line at 614 nm was observed. These phosphors might be promising components with possible application in the fields of near UV‐ and blue‐excited white light‐emitting diodes. Simultaneously, this novel and efficient pathway could open new opportunities for further investigating the properties of molybdate materials. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
8.
M. Bhushana Reddy S. Sailaja K. Vemasevana Raju C. Nageswara Raju P. Giridhar B. Vengala Rao B. Sudhakar Reddy 《Luminescence》2011,26(6):680-684
Rare earth ions (Eu3+ or Tb3+)‐activated Ca3 Ga2 Si3O12 (CaGaSi) phosphors were synthesized by using a sol–gel method. Photoluminescence spectra of Eu3+:CaGaSi phosphors exhibited five emission bands at 578, 592, 612, 652 and 701 nm, which were assigned to the transitions (5D0 → 7F0, 7F1, 7F2, 7F3 and 7F4), respectively, with an excitation wavelength of λexci = 392 nm. Among these, the transition 5D0 → 7F2 (612 nm) displayed bright red emission. In the case of Tb3+:CaGaSi phosphors, four emission bands were observed at 488 (5D4 → 7F6), 543 (5D4 → 7F5), 584 (5D4 → 7F4) and 614 nm (5D4 → 7F3) from the measurement of PL spectra with λexci = 376 nm. Among these, the transition 5D4 → 7F5 at 543 nm displayed bright green emission. The structure and morphology of the phosphors were studied from the measurements of X‐ray diffraction (XRD), scanning electron microscopy (SEM) and energy‐dispersive X‐ray analysis (EDAX) results. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
9.
The Eu2+/Eu3+ mixed valence phosphor Ca2SiO2F2:Eu2+/Eu3+ was prepared using a solid‐state reaction synthesis method in a CO atmosphere, and the optical properties were investigated. The spectroscopic properties revealed that Ca2+ ions were occupied by both Eu2+ and Eu3+ ions in Ca2SiO2F2, and both ions were able to generate their characteristic emissions. A broad 5d → 4f Eu2+ band at ~470 nm and narrow 4f → 4f Eu3+ peaks upon excitation with n‐UV light were observed. The ratio between Eu2+ and Eu3+ emissions changed regularly, and the relative intensity of the red component from Eu3+ became systematically stronger with increasing overall Eu content. As a result, the emission color of these phosphors can be tunable from blue to pink under n‐UV light excitation. 相似文献
10.
Photoluminescence properties of Ca2Al2O5:RE3+ (RE = Eu,Dy and Tb) phosphors for solid state lighting
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Atul N. Yerpude Vishal R. Panse Sanjay J. Dhoble Namdeo S. Kokode Mudavath Srinivas 《Luminescence》2017,32(7):1361-1364
Ca2Al2O5:Eu3+, Ca2Al2O5:Dy3+ and Ca2Al2O5:Tb3+ phosphors were synthesized using a combustion synthesis method. The prepared phosphors were characterized by X‐ray powder diffraction for phase purity, by scanning electron microscopy for morphology, and by photoluminescence for emission and excitation measurements. The Ca2Al2O5:Eu3+ phosphors could be efficiently excited at 396 nm and showed red emission at 594 nm and 616 nm due to 5D0 → 7F1 and 5D0 → 7F2 transitions. Dy3+‐doped phosphors showed blue emission at 482 nm and yellow emission at 573 nm. Ca2Al2O5:Tb3+ phosphors showed emission at 545 nm when excited at 352 nm. Concentration quenching occurred in both Eu3+ and Dy3+phosphors at 0.5 mol%. Photoluminescence results suggested that the aluminate‐based phosphor could be a potential candidate for application in environmentally friendly based lighting technologies. 相似文献
11.
Zn‐doped CaTiO3:Eu3+ red phosphors for enhanced photoluminescence in white light‐emitting diodes (LEDs) were synthesized by a solid‐state method. The structure and morphology of the obtained phosphor samples were observed by X‐ray diffraction (XRD) and scanning electron microscopy (SEM), and the impact of Ca, Zn and Eu content on their photoluminescence properties was studied. The results indicated that Zn not only participates in the formation of defects in suitable lattice matrices but also has a role in flux in the transformation from ZnO to Zn2TiO4, which is beneficial for the enhancement of photoluminescence properties. Photoluminescence test data showed that the Zn‐doped phosphor is excited efficiently by near‐ultraviolet (NUV) light at wavelengths around 398 nm and emits an intense red light with a broad peak around 616 nm corresponding to the 5D0→7F2 transition of Eu3+. The intensity of this phosphor emission is three times stronger than that without Zn‐doping. Furthermore, this phosphor has very good thermal stability, high color purity and a low sintered temperature, all of which suggest its potential as a promising red phosphor for white LEDs. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
12.
Photoluminescence properties of LiBaPO4:M3+ phosphor for near‐UV light‐emitting diode (M = Eu and Dy)
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A novel phosphor LiBaPO4 doped with rare earths Eu and Dy prepared by high temperature solid‐state reaction method is reported. The phosphors were characterized by X‐ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL). The emission and excitation spectra of these materials were measured at room temperature with a spectrofluorophotometer. The excitation spectra of LiBaPO4:Eu3+ phosphor can be efficiently excited by 394 nm, which is matched well with the emission wavelength of near‐UV light‐emitting diode (LED) chip. PL properties of Eu3+‐doped LiBaPO4 exhibited the characteristic red emission coming from 5D0 → 7 F1 (593 nm) and 5D0 → 7 F2 (617 nm) electronic transitions with color co‐ordinations of (0.680, 0.315). The results demonstrated that LiBaPO4:Eu3+ is a potential red‐emitting phosphor for near‐UV LEDs. Emission spectra of LiBaPO4:Dy3+ phosphors showed efficient blue (481 nm) and yellow (574 nm) bands, which originated from 4 F9/2 → 6H15/2 and 4 F9/2 → 6H13/2 transitions of the Dy3+ ion, respectively. The 574 nm line is more intense than the 481 nm lines, which indicates that the site Dy3+ is located with low symmetry. This article summarizes fundamentals and possible applications of optically useful inorganic phosphates with visible photoluminescence of Eu3+ and Dy3+ ions. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
13.
Sonika Kadyan Kuldeep Singh Sitender Singh Suman Sheoran Jasbir Singh Devender Singh 《Luminescence》2020,35(5):673-683
The solution combustion technique was used to synthesize MLaAl3O7 (M = Ba, Ca, Mg, and Sr) nanophosphors‐doped with Eu3+ using metal nitrates as precursors. The photoluminescence (PL) emission spectra exhibited three peaks at 587–591, 610–616, and 653–654 corresponding to 5D0→7F1, 5D0→7F2, and 5D0→7F3 transitions, respectively. Upon excitation at 254 nm, these nanophosphors displayed strong red emission with the dominant peak attributed to the 5D0→7F2 transition of Eu3+. The materials were further heated at 900 and 1050°C for 2 h to examine the consequence of temperature on crystal lattice and PL emission intensity. X‐ray diffraction (XRD) analysis proved that all the synthesized materials were of a crystalline nature. CaLaAl3O7 material has a tetragonal crystal structure with space group P421m. Scherer's equation was used to calculate the crystallite size of synthesized phosphors using XRD data. A Fourier transformation infrared study was used to observe the stretching vibrations of metal–oxygen bonds. Infrared peaks for stretching vibrations corresponding to lanthanum–oxygen and aluminium–oxygen bonds were found at 582 and 777 cm–1 respectively for CaLaAl3O7 phosphor material. Transmission electron microscopy images were used to determine the size of particles (18–37 nm for the as‐prepared materials) and also to analyze the three‐dimensional view of these materials. The experimental data indicate that these materials may be promising red‐emitting nanophosphors for use in white light‐emitting diodes. 相似文献
14.
Effect of replacement of Ca by Zn on the structure and optical property of CaTiO3:Eu3+ red phosphor prepared by sol‐gel method
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Eu3+‐doped calcium titanate red phosphors, Ca1‐xZnxTiO3:Eu3+, were prepared by the sol‐gel method. The structure of prepared Ca1‐xZnxTiO3:Eu3+ phosphors were investigated by X‐ray diffraction and infrared spectra. Due to the 5D0 → 7F1–3 electron transitions of Eu3+ ions, photoluminescence spectra showed a red emission at about 619 nm under excitation of 397 nm and 465 nm, respectively. When zinc was added to the host, the luminescent intensity of Ca1‐xZnxTiO3:Eu3+ was markedly improved several fold compared with that of CaTiO3:Eu3+. Ca0.9Zn0.1TiO3:Eu3+ also had higher luminescence intensity than the commercially available Y2O3:Eu3+ phosphors under UV light excitation. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
15.
Eu3+‐activated MAl(SO4)2Br phosphors (where M = Mg or Sr) are successfully prepared using a wet chemical reaction technique. The samples are characterized by X‐ray diffraction (XRD) and photoluminescence (PL) spectroscopies. The XRD pattern revealed that both the samples are microcrystalline in nature. PL of Eu3+‐doped SrAl(SO4)2Br and MgAl(SO4)2Br phosphors exhibited characteristic red emission coming from the 5D0 → 7F2 (616 nm) electron transition, when excited by 396 nm wavelength of light. The maximum intensity of luminescence was observed at a concentration of 1 mol% Eu3+. The intensity of the electric dipole transition at 616 nm is greater than that of the magnetic dipole transition at 594 nm. The results showed that MAl(SO4)2Br:Eu3+, (M = Mg, Sr) phosphors have potential application in near‐UV light‐emitting diodes as efficient red‐emitting phosphor. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
16.
Feng‐Nian Wu Hua‐Jian Yu Yan‐Yan Hu Hua‐Di Zhang Rui Zhang Jing Li Bing Liu Xu‐Ping Wang Yu‐Guo Yang Lei Wei 《Luminescence》2021,36(1):237-246
(Ca1‐xEux)WO4 (x = 0–21 mol%) phosphors were prepared using the classical solid‐state reaction method. The influence of Eu3+ ion doping on lattice structure was observed using powder X‐ray diffraction and Fourier transform infrared spectroscopy. Furthermore, under this influence, the luminescence properties of all samples were analyzed. The results clearly illustrated that the element europium was successfully incorporated into the CaWO4 lattice with a scheelite structure in the form of a Eu3+ ion, which introduced a slight lattice distortion into the CaWO4 matrix. These lattice distortions had no effect on phase purity, but had regular effects on the intrinsic luminescence of the matrix and the f–f excitation transitions of Eu3+ activators. When the Eu3+ concentration was increased to 21 mol%, a local luminescence centre of [WO4]2? groups was detected in the matrix and manifested as the decay curves of [WO4]2? groups and luminescence changed from single exponential to double exponential fitting. Furthermore, the excitation transitions of Eu3+ between different energy levels (such as 7F0→5L6, 7F0→5D2) also produced interesting changes. Based on analysis of photoluminescence spectra and the chromaticity coordinates in this study, it could be verified that the nonreversing energy transfer of [WO4]2?→Eu3+ was efficient and incomplete. 相似文献
17.
Ashish Akojwar K. N. Shinde Roshani Singh S. J. Dhoble N. S. Kokode 《Luminescence》2016,31(1):305-308
A series of phosphors KAl1‐xPO4Cl:Eux3+ (0.1 ≤ x ≤ 1.0) was synthesized using a facile combustion method using urea as a fuel and their structural, morphological and photoluminescence properties were investigated. It was found that the particle size was in the range of 1–2 µm with an irregular shape. The f–f transitions of Eu3+ in the host lattice were assigned and discussed. The excitation and emission spectra indicated that this phosphor can be efficiently excited by ultraviolet (395 nm), and exhibit reddish orange emission corresponding to the 5D0→7FJ (J = 0, 1, 2) transitions of Eu3+. The impact of the Eu3+ concentration on the relative emission intensity was investigated, and the best doping concentration is 0.5. The present study suggests that the KAl0.5PO4Cl: Eu0.53+ phosphor is a strong candidate as a red component for phosphor‐ converted white light‐emitting diodes (LEDs). Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
18.
The wet chemical synthesis, X‐ray diffraction and photoluminescence characteristics in alkaline halosulfate phosphors such as LiMgSO4Cl:Eu and LiZnSO4Cl:Eu are reported in this paper. The effect of Li ion on Eu3+ luminescence (5D0 → 7F2 electronic transition) and incorporation of Eu3+ ion in lithium base alkaline halosulfate phosphor has been studied. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
19.
Eu3+‐doped 6LaPO4–3La3PO7–2La7P3O18 red luminescent phosphors were synthesized by co‐deposition and high‐temperature solid‐state methods and its polyphase state was confirmed by X‐ray diffraction analysis. Transmission electron microscopy showed the grain morphology as a mixture of rods and spheres. Luminescence properties of the phosphor were investigated and its red emission parameters were evaluated as a function of Eu3+ concentration (3.00–6.00 mol%). Excitation spectra of 6LaPO4–3La3PO7–2La7P3O18:Eu3+ showed strong absorption bands at 280, 395, and 466 nm, while the luminescence spectra exhibited prominent red emission peak centred at 615 nm (5D0→7F2) in the red region. CIE chromaticity coordinates of the 6LaPO4–3La3PO7–2La7P3O18:5%Eu3+ phosphor were (0.668, 0.313) in the red region, and defined its potential application as a red phosphor. 相似文献
20.
KLaSiO4:Tb3+ phosphors were synthesized using the sol–gel method. The structure and luminescence properties of the materials were characterized using X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, thermogravimetry–differential thermal analysis, fluorescence spectra and calculated Commission Internationale de l'éclairage coordinates. The results showed that the material had a hexagonal structure, and that doping of Tb3+ did not change the crystal structure of KLaSiO4. FTIR spectroscopy confirmed the existence of stretching vibrations of Si–O, bending vibrations of Si–O–Si, and asymmetric tensile vibrations of Si–O in KLaSiO4. The excitation spectrum of the sample consisted of 4f7→5d1 broadband absorption and the characteristic excitation peak of Tb3+, the excitation peak at 232 nm belongs to the spin allowed 7FJ→7DJ transition of Tb3+, the excitation peak at 268 nm belongs to the spin forbidden 7FJ→9DJ transition of Tb3+, and the absorption band of 7FJ→7DJ transition is split. Under excitation at 232 nm, the emission peak of the sample was composed of the 5D4→7FJ (J = 6, 5, 4, 3) energy level transition of Tb3+. The highest emission peak is located at 543 nm, which belongs to the 5D4→7F5 transition and emits green light. Concentration quenching occurred when the Tb3+ doping concentration was greater than 1% mol, the quenching mechanism was an electric dipole–electric dipole action. When the ratio of citric acid to total metal ions was 1:1 and the annealing temperature was 800°C, the surface defects of the phosphors were greatly reduced, the quenching effect was reduced, and the luminous intensity reached the maximum. 相似文献