Energy transfer in single phase Eu3+-doped Y2WO6 phosphors

Llanos, Jaime; Espinoza, Darío; Castillo, Rodrigo

doi:10.1039/c7ra00886d

Cited by 26 publications

(6 citation statements)

References 35 publications

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“…asymmetry ratio can be used as an index to assess the site symmetry around the Eu 3+ ions. 40,[50][51][52] The (ED) 5 D 0 / 7 F 2 transition is a hypersensitive transition as this type of transition is really sensitive to the local environment, while the (MD) 5 D 0 / 7 F 1 transition is insensitive to the local environment at Eu 3+ site. 53,54 The calculated R value for Ba 2 Lu 4.48 Eu 0.5 La 0.02 B 5 O 17 phosphor was determined to be 2.88.…”

Section: View Article Onlinementioning

confidence: 99%

Photoluminescence properties of novel Ba₂Lu₅B₅O₁₇:Eu³⁺ red emitting phosphors with high color purity for near-UV excited white light emitting diodes

et al. 2018

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A series of new red-emitting Ba 2 Lu 4.98Àx Eu x La 0.02 B 5 O 17 (0.1 # x # 1.0) phosphors were synthesized via the high-temperature solid-state reaction method. The phase formation of the as-synthesized Ba 2 Lu 4.48 Eu 0.5 La 0.02 B 5 O 17 phosphor was confirmed by powder X-ray diffraction analysis. It was found that La 3+ doping resulted in the reduction of LuBO 3 impurities and thus pure phase Ba 2 Lu 5 B 5 O 17 was realised. The morphology of Ba 2 Lu 4.48 Eu 0.5 La 0.02 B 5 O 17 phosphors was studied by field emission scanning electron microscopy (FE-SEM). As a function of Eu 3+ concentration the photoluminescence spectra and decay lifetimes were investigated in detail. Under excitation at 396 nm, a dominant red emission peak located at 616 nm ( 5 D 0 / 7 F 2 ) indicated that Eu 3+ ions mainly occupied low symmetry sites with a noninversion center in Ba 2 Lu 4.48 Eu 0.5 La 0.02 B 5 O 17 . The optimal Eu 3+ ion concentration was found to be x ¼ 0.5 and the critical distance of Eu 3+ was determined to be 6.55Å. In addition, the concentration quenching takes place via dipole-dipole interactions. The phosphors exhibited good CIE (Commission International de I'Eclairage) color coordinates (x ¼ 0.643, y ¼ 0.356) situated in the red region and a high color purity of 97.8%. Furthermore, the internal quantum efficiency and the thermal stability of Ba 2 Lu 4.48 Eu 0.5 La 0.02 B 5 O 17 phosphors were also investigated systematically. The results suggest that Ba 2 Lu 4.48 Eu 0.5 La 0.02 B 5 O 17 may be a potential red phosphor for white light-emitting diodes.

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Section: View Article Onlinementioning

confidence: 99%

Photoluminescence properties of novel Ba₂Lu₅B₅O₁₇:Eu³⁺ red emitting phosphors with high color purity for near-UV excited white light emitting diodes

et al. 2018

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“…The apparent preference of Sm for the Y1 and Y3 sites at concentrations < 9% of Sm may have implications for the optical properties of this material, since the interatomic distance Y1 -Y3 is the shortest of all the possible Y -Y lengths in this crystal structure (see Table 3) and Y3 -Y3 is only slightly longer. The substitution pattern seems to be somewhat different to similar systems such as Eu 3+ -doped Y2WO6, in which Eu 3+ seems to occupy Y1 and Y2 sites at low concentrations while at higher concentrations Y3 is gradually also occupied [42] despite the similarity of the ionic radii of Sm 3+ and Eu 3+ . In La 3+ -doped Y2WO6, the larger La 3+ (eightfold 1.16 Å) mainly occupies the Y2 and Y3 sites [43].…”

Section: X-ray Diffractionmentioning

confidence: 57%

“…The intercept on the vertical axis in Figure 7 is not equal to zero, which could indicate the Sm 3+ ions cluster at all compositions, a result in line with the analysis obtained from the calculation of the critical distance. A quite different situation is observed in the Eudoped phosphors, which follow the Inokuti-Hirayama model [42].…”

Section: Luminescence Spectramentioning

confidence: 93%

Energy transfer, structural and luminescent properties of the color tunable phosphor Y2WO6:Sm3+

Espinoza

Allan

Castillo

et al. 2020

Journal of Alloys and Compounds

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Inorganic phosphors based on monoclinic Y2WO6 doped with Sm 3+ ions were prepared via conventional solid-state reactions at high temperature. A total of six samples were obtained with different Sm 3+ concentrations (0-9%). The purity of the as-prepared phases was checked by powder X-ray diffraction (PXRD). The excitation, emission, and time-resolved emission spectra were examined in detail. The experimental decay curves were fitted to the Inokuti-Hirayama model, showing that the Sm 3+ ions form clusters at all compositions.Periodic hybrid density functional theory calculations were also carried out on the undoped material and on 144-atom supercells of stoichiometry Y1.9375Sm0.0625WO6 and Y1.875Sm0.125WO6. The different coordination environments at the Y1, Y2 and Y3 sites are analysed in detail. The calculated structure and band gap of Y2WO6 are in good agreement with experiment with one potentially important discrepancy in a Y3-O bond length. The thermodynamically favoured substitution sites for Sm, Y2 and Y3, in the supercell are not those observed under the preparation conditions used here, since the experimental Rietveld analysis suggests occupation of Y1 at all concentrations. Analogous calculations for the Eu-doped system highlight marked differences between Eu and Sm despite their similar ionic sizes. The calculated densities of states show the position of the 4f levels in the band gap depend on the 2 sites occupied by the dopants and thus expect marked differences in the luminescence spectra, opening up possibilities for tuning device performance.

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“…Consistent with the recorded excitation and emission spectra (Figure c) of BaSO 4 reference and sample (λ ex = 394 nm) and using the above equation, the IQE of NLW:0.8Eu 3+ red phosphor is calculated and found to be 83.76%. This IQE value is a lot higher when contrasted with that of the commercial phosphor Y 2 O 3 :Eu 3+ (12%) and some other Eu 3+ -activated red phosphors, for instance LiGd(WO 4 ) 2 :Eu 3+ (69%), Y 2 WO 6 :Eu 3+ (63.1%), and Y 2 SiWO 8 :Eu 3+ (14.8%) . Moreover, with the help of absorption efficiency (ε), the external quantum efficiency (EQE) was calculated for Na 2 La 3.2 (WO 4 ) 7 :0.8Eu 3+ phosphor by utilizing the subsequent equation: ε = ∫ E normalR − prefix∫ E normalS ∫ E normalR …”

Section: Resultsmentioning

confidence: 98%

Oxide-Based Red Emitting Phosphors with High Color Purity and Their Versatile Applications: Synthesis, Structure, and Luminescence Properties

Pradhan

Singh

Maram

et al. 2022

ACS Appl. Opt. Mater.

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The oxide-based narrow band red emitting phosphor is critical and assumes a fundamental part to upgrade the overall efficiency of the white LED. In this regard, a series of Eu3+-activated Na2La4(WO4)7 (NLW) red emitting phosphors were synthesized employing a solid state approach, and we examined their optical properties in detail. All of the compositions crystallize in tetragonal structure with a I41/a space group. Sharp red emission was exhibited by all the NLW:Eu3+ phosphors ∼616 nm owing to the ED transition (5D0 → 7F2), under the excitation of 394 nm and observed concentration quenching when x = 0.8. In addition, color purity and IQE of Na2La3.2(WO4)7:0.8Eu3+ phosphor is found to be 96.79% and 83.76%, respectively. A temperature-dependent PL study reveals the thermal stability of the phosphor as 69.75% at 423 K. Red and white LEDs were fabricated utilizing the synthesized phosphor to understand their practical applicability. EL spectra of the red LED displayed intense red emission, whereas white LED exhibited warm white light with high CRI (80) and low CCT (5730K) values. These Eu3+-doped red phosphors can also be used for latent fingerprint application. Moreover, a series of Sm3+ and simultaneous activation of both Sm3+ and Eu3+ in NLW phosphors were synthesized, and investigated their optical properties. By using the Sm3+-codoped Eu3+-activated phosphor, a red/deep red LED is fabricated for the plant growth purpose. These outcomes suggested that the synthesized phosphors could be promising phosphors for the WLED, security, and plant growth applications.

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Energy transfer in single phase Eu³⁺-doped Y₂WO₆ phosphors

Abstract: Inorganic phosphors based on monoclinic Y2WO6 doped with Eu3+ ions were prepared via conventional solid-state reactions at high temperature.

Cited by 26 publications

References 35 publications

Photoluminescence properties of novel Ba₂Lu₅B₅O₁₇:Eu³⁺ red emitting phosphors with high color purity for near-UV excited white light emitting diodes

Photoluminescence properties of novel Ba₂Lu₅B₅O₁₇:Eu³⁺ red emitting phosphors with high color purity for near-UV excited white light emitting diodes

Energy transfer, structural and luminescent properties of the color tunable phosphor Y2WO6:Sm3+

Oxide-Based Red Emitting Phosphors with High Color Purity and Their Versatile Applications: Synthesis, Structure, and Luminescence Properties

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Energy transfer in single phase Eu3+-doped Y2WO6 phosphors

Abstract: Inorganic phosphors based on monoclinic Y2WO6 doped with Eu3+ ions were prepared via conventional solid-state reactions at high temperature.

Cited by 26 publications

References 35 publications

Photoluminescence properties of novel Ba2Lu5B5O17:Eu3+ red emitting phosphors with high color purity for near-UV excited white light emitting diodes

Photoluminescence properties of novel Ba2Lu5B5O17:Eu3+ red emitting phosphors with high color purity for near-UV excited white light emitting diodes

Energy transfer, structural and luminescent properties of the color tunable phosphor Y2WO6:Sm3+

Oxide-Based Red Emitting Phosphors with High Color Purity and Their Versatile Applications: Synthesis, Structure, and Luminescence Properties

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Energy transfer in single phase Eu³⁺-doped Y₂WO₆ phosphors

Photoluminescence properties of novel Ba₂Lu₅B₅O₁₇:Eu³⁺ red emitting phosphors with high color purity for near-UV excited white light emitting diodes

Photoluminescence properties of novel Ba₂Lu₅B₅O₁₇:Eu³⁺ red emitting phosphors with high color purity for near-UV excited white light emitting diodes