Dopant distribution and influence of sonication temperature on the pure red light emission of mixed oxide phosphor for solid state lighting

Som, Sudipta; Kumar, Vijay; Kumar, Vinod; Gohain, Mukut; Pandey, Anurag; Duvenhage, Mart‐Mari; Terblans, J.J.; Bezuindenhoud, B.C.B.; Swart, H.C.

doi:10.1016/j.ultsonch.2015.07.003

Cited by 26 publications

(7 citation statements)

References 60 publications

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“…Figure shows the UV–vis diffuse reflectance spectra of Gd 2 O 2 S:Eu 3+ nanophosphor powder prepared by microwave irradiation and γ‐irradiation methods against a reference standard compound (BaSO 4 ). Weak broad bands were observed at 325 nm and corresponded to the formation of metastable energy states between the valence band and the conduction band by the Eu 3+ ions . In addition, weak bands were observed from 350 to 600 nm; these were associated with the intraconfigurational f−f transition from ground state 7 F 0 to the higher excited states 5 L 6 (390 nm), 5 D 2 (465 nm), and 5 D 1 (538 nm) for both doped samples .…”

Section: Resultsmentioning

confidence: 92%

Physical and optical studies of Gd₂O₂S:Eu³⁺ nanophosphors by microwave irradiation and γ‐irradiation methods

et al. 2019

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Gd 2 O 2 S:Eu 3+ nanophosphors have been successfully synthesized using microwave irradiation and γ-irradiation methods with polyvinyl pyrrolidone as a stabilizer. The physical and luminescence spectra were compared. The morphologies of both Gd 2 O 2 S:Eu 3+ nanophosphors were in the hexagonal phase and mainly consisted of spherical nanostructures with diameters of~90 nm and~50 nm for both microwave irradiation and γ-irradiation methods. Upon 325 nm of ultraviolet (UV) light excitation, strong red emissions (626 nm) were observed for both methods; these emissions corresponded to the 5 D 0 → 7 F 2 transition of Eu 3+ ions. However, Gd 2 O 2 S:Eu 3+ nanophosphors following microwave treatment showed better luminescence intensity than Gd 2 O 2 S:Eu 3+ nanophosphors treated with γ-irradiation. This difference was attributed to the crystallinity phase and surface quenching effects of Gd 2 O 2 S: Eu 3+ nanophosphors. The reaction mechanisms of Gd 2 O 2 S:Eu 3+ nanophosphors in both methods are discussed in detail.

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Section: Resultsmentioning

confidence: 92%

Physical and optical studies of Gd₂O₂S:Eu³⁺ nanophosphors by microwave irradiation and γ‐irradiation methods

et al. 2019

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“…respectively. The lowering of the band gap of (Gd,Y)VO 4 as compared to YVO 4 is attributed to the fact that the Gd 3+ ions form some metastable states between the valence band and conduction band (Som et al, 2016).…”

Section: Band Gap Calculationsmentioning

confidence: 99%

“…have been synthesized and studied with the aim of achieving spectral conversion in solar cells (Heng et al, 2016;Zhydachevskii et al, 2014;Wegh et al, 1999;Wei et al, 2011). Out of these available materials, orthovanadates such as YVO 4 and GdVO 4 have received considerable attention owing to their unique spectral properties, including narrow emission bandwidths, large Stokes shifts, high luminescence efficiencies and longer lifetimes (Som et al, 2016). Although there are many reports on GdVO 4 and YVO 4 based phosphors, there are very few reports on the composite (Gd,Y)VO 4 based nanophosphors (Som et al, 2016;Kumari & Manam, 2015;Chen et al, 2011;Wang et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

“…Out of these available materials, orthovanadates such as YVO 4 and GdVO 4 have received considerable attention owing to their unique spectral properties, including narrow emission bandwidths, large Stokes shifts, high luminescence efficiencies and longer lifetimes (Som et al, 2016). Although there are many reports on GdVO 4 and YVO 4 based phosphors, there are very few reports on the composite (Gd,Y)VO 4 based nanophosphors (Som et al, 2016;Kumari & Manam, 2015;Chen et al, 2011;Wang et al, 2009). To the best of our knowledge, this is the first report on the synthesis, mechanism, and structural and photoluminescence (PL) characterization of Sm 3+ doped (Gd,Y)VO 4 based downconversion nanophosphors.…”

Section: Introductionmentioning

confidence: 99%

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Appearance of efficient luminescence energy transfer in doped orthovanadate nanocrystals

et al. 2017

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This paper reports the detailed synthesis mechanism and the structural, morphological and optical characterization of ultraviolet ($311 nm) excitable samarium doped gadolinium yttrium orthovanadate, (Gd,Y)VO 4 :Sm 3+ , nanocrystals. X-ray diffraction and Rietveld refinement studies confirmed that the synthesized samples crystallize in a tetragonal structure with I41/amd space group. The enhanced photoluminescence intensity of (Gd,Y) 3+ luminescence are discussed in detail. The optical band gap of the as-prepared nanocrystals has been estimated using UV-vis-NIR absorption spectroscopy, which reveals a slightly higher band gap (3.75 eV) for YVO 4 as compared to GdYVO 4 (3.50 eV). Furthermore, confocal microcopy, decay parameters and Commission Internationale de l'Eclairage chromatic coordinates have supplemented these studies, which established the suitability of these nanophosphors for achieving spectral conversion in silicon solar cells.

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“…Multi-cation material provides flexibility to engineer its physical and/ or chemical behavior by varying the composition [ 21 ]. The n-type bi-cation transparent conducting oxide such as ZnO-In 2 O 3 has revealed change in its work function, bandgap energy, resistivity and acid etching rate as the function of Zn/In content [ 22 ].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Behavior of Cetyltrimethyl Ammonium Bromide Stabilized Zn1+xSnO3+x (0 ≤ x ≤1) Nano-Crystallites

2016

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We report synthesis of cetyltrimethyl ammonium bromide (CTAB) stabilized Zn1+xSnO3+x (0 ≤ x ≤1) nano-crystallites by facile cost-effective wet chemistry route. The X-ray diffraction patterns of as-synthesized powders at the Zn/Sn ratio of 1 exhibited formation of ZnSn(OH)6. Increasing the Zn/Sn ratio further resulted in the precipitation of an additional phase corresponding to Zn(OH)2. The decomposition of these powders at 650°C for 3h led to the formation of the orthorhombic phase of ZnSnO3 and tetragonal SnO2-type phase of Zn2SnO4 at the Zn/Sn ratio of 1 and 2, respectively, with the formation of their mixed phases at intermediate compositions, i.e., at Zn/Sn ratio of 1.25, 1.50 and 1.75, respectively. The lattice parameters of orthorhombic and tetragonal phases were a ~ 3.6203 Å, b ~ 4.2646 Å and c ~ 12.8291Å (for ZnSnO3) and a = b ~ 5.0136 Å and c ~ 3.3055Å (for Zn2SnO4). The transmission electron micrographs revealed the formation of nano-crystallites with aspect ratio ~ 2; the length and thickness being 24, 13 nm (for ZnSnO3) and 47, 22 nm (for Zn2SnO4), respectively. The estimated direct bandgap values for the ZnSnO3 and Zn2SnO4 were found to be 4.21 eV and 4.12 eV, respectively. The ac conductivity values at room temperature (at 10 kHz) for the ZnSnO3 and Zn2SnO4 samples were 8.02 × 10−8 Ω-1 cm-1 and 6.77 × 10−8 Ω-1 cm-1, respectively. The relative permittivity was found to increase with increase in temperature, the room temperature values being 14.24 and 25.22 for the samples ZnSnO3 and Zn2SnO4, respectively. Both the samples, i.e., ZnSnO3 and Zn2SnO4, exhibited low values of loss tangent up to 300 K, the room temperature values being 0.89 and 0.72, respectively. A dye-sensitized solar cell has been fabricated using the optimized sample of zinc stannate photo-anode, i.e., Zn2SnO4. The cyclic voltammetry revealed oxidation and reduction around 0.40 V (current density ~ 11.1 mA/cm2) and 0.57 V (current density– 11.7 mA/cm2) for Zn2SnO4 photo-anode in presence of light.

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Dopant distribution and influence of sonication temperature on the pure red light emission of mixed oxide phosphor for solid state lighting

Cited by 26 publications

References 60 publications

Physical and optical studies of Gd₂O₂S:Eu³⁺ nanophosphors by microwave irradiation and γ‐irradiation methods

Physical and optical studies of Gd₂O₂S:Eu³⁺ nanophosphors by microwave irradiation and γ‐irradiation methods

Appearance of efficient luminescence energy transfer in doped orthovanadate nanocrystals

Synthesis and Behavior of Cetyltrimethyl Ammonium Bromide Stabilized Zn1+xSnO3+x (0 ≤ x ≤1) Nano-Crystallites

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Dopant distribution and influence of sonication temperature on the pure red light emission of mixed oxide phosphor for solid state lighting

Cited by 26 publications

References 60 publications

Physical and optical studies of Gd2O2S:Eu3+ nanophosphors by microwave irradiation and γ‐irradiation methods

Physical and optical studies of Gd2O2S:Eu3+ nanophosphors by microwave irradiation and γ‐irradiation methods

Appearance of efficient luminescence energy transfer in doped orthovanadate nanocrystals

Synthesis and Behavior of Cetyltrimethyl Ammonium Bromide Stabilized Zn1+xSnO3+x (0 ≤ x ≤1) Nano-Crystallites

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Physical and optical studies of Gd₂O₂S:Eu³⁺ nanophosphors by microwave irradiation and γ‐irradiation methods

Physical and optical studies of Gd₂O₂S:Eu³⁺ nanophosphors by microwave irradiation and γ‐irradiation methods