Synthesis and characterization of physical properties of Gd2O2S:Pr3+ semi-nanoflower phosphor

Bagheri, Alireza; Saraee, Kh. Rezaee Ebrahim; Shakur, H.R.; Zeinali, H. Zamani

doi:10.1007/s00339-016-0058-z

Cited by 20 publications

(19 citation statements)

References 23 publications

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“…Ln 2 O 2 S nanoparticles are synthesized either in an aqueous or organic medium, which requires two different sulfidation methods. In water, sulfidation is performed in a subsequent step by heating the precursors at high temperature (T>600 °C) using either sulfur vapor, CS 2 formed in situ (S 8 in carbon), or H 2 S . In organic medium, sulfidation is achieved at milder temperatures and in a single step.…”

Section: Introductionmentioning

confidence: 99%

Thermal Stability of Oleate‐Stabilized Gd₂O₂S Nanoplates in Inert and Oxidizing Atmospheres

et al. 2019

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Capping ligands play an important role in the chemistry of nanoparticles synthesized with organic surfactants. This is relevant to a number of device applications where heating may cause major modifications of crystalline nanoparticles including amorphization, surface rearrangements or sintering. Ultrathin monodisperse Ln 2 O 2 S x oxysulfide nanoparticles (Ln = lanthanide) obtained in a mixture of oleylamine, oleic acid and 1-octadecene show promising luminescence and light absorption properties. In view of applications, one open question concerns the thermal behavior and the role of the ligands on the thermal reactivity of the nanoparticles. In this report, we show that the thermal stability of Gd 2 O 2 S x nanocrystals is limited because of their non-stoichiometric composition and strongly depends on the annealing atmosphere. The sintering temperature of the nanoparticles is lower in air than in inert atmosphere because of a rapid degradation of the ligands. Annealing the nanoparticles in air enables removing the ligands without altering the nanocrystals structure. The decomposition of the Gd 2 O 2 S x nanocrystals in inert atmosphere exhibits a complex multistep behavior that was precisely modeled. This work gives a comprehensive description of the stability conditions of lanthanide oxysulfide nanoparticles. It establishes the conditions for their practical use and opens the way to major improvements of the surface activity of Ln 2 O 2 S nanoparticles and related nanocrystals.

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Section: Introductionmentioning

confidence: 99%

Thermal Stability of Oleate‐Stabilized Gd₂O₂S Nanoplates in Inert and Oxidizing Atmospheres

et al. 2019

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“…The quality of a phosphor/scintillator powder is related not only to chemical and phase purity but also to the size/size distribution and morphology of the particles . For example, ~3‐10 μm sized particles were reported to provide an optimal packing condition and match the required scintillator features in planar X‐ray applications .…”

Section: Introductionmentioning

confidence: 99%

“…The quality of a phosphor/scintillator powder is related not only to chemical and phase purity but also to the size/ size distribution and morphology of the particles. 24 For example,~3-10 lm sized particles were reported to provide an optimal packing condition and match the required scintillator features in planar X-ray applications. 23 The synthesis of RE 2 O 2 S with high purity is, first of all, rather challenging, since RE has a much lower affinity toward S than O according to the hard and soft acid and base (HSAB) theory.…”

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confidence: 99%

Photo/cathodoluminescence and stability of Gd₂O₂S:Tb,Pr green phosphor hexagons calcined from layered hydroxide sulfate

Wang

et al. 2018

J Am Ceram Soc

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Hydrothermal reaction at 150°C and pH = 10 for 24 hours crystallized (Gd,RE)2(OH)4SO4 layered hydroxide sulfate (monoclinic structure; RE = Pr, Tb), from which Gd2O2S:RE (hexagonal structure) green phosphor hexagons were derived via facile dehydration in flowing H2 at 1200°C. Rietveld refinement of the XRD patterns yielded cell dimensions that confirmed the direct crystallization of solid solution. Photoluminescence (PL) study at room temperature found absolute quantum yields of ~25.1% and 28.4%, CIE chromaticity coordinates of (0.145, 0.679) and (0.326, 0.566), and fluorescence lifetimes of ~2.36 μs and 1.21 ms for Pr3+ and Tb3+ under 300 and 275 nm UV excitations, respectively. Temperature‐dependent PL analysis (25‐200°C) indicated that both the Pr3+‐ and Tb3+‐doped phosphors have favorably good thermal stability and retained ~65% and 80% at 100°C and ~41% and 47% at 200°C of their initial emission intensities, respectively. The activation energy for the thermal quenching of PL was determined to be ~0.221 (Pr3+) and 0.314 eV (Tb3+). Cathodoluminescence (CL) found that both the phosphors exhibit increasingly higher emission intensity/brightness at a higher acceleration voltage (up to 7 kV) or beam current (up to 50 μA) and are stable under electron bombardment in the studied range. Raising beam current was suggested to be more effective to enhance CL.

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“…reaction (Bagheri et al, 2016). However, the sulfidation process is a solid-solid reaction with S 8 at 900 • C for 1 h.…”

Section: Urea-based Synthesesmentioning

confidence: 99%

Metal Oxysulfides: From Bulk Compounds to Nanomaterials

Larquet

Carenco

2020

Front. Chem.

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This review summarizes the syntheses and applications of metal oxysulfides. Bulk compounds of rare earth and transition metals are discussed in the section Introduction. After a presentation of their main properties and applications, their structures are presented and their syntheses are discussed. The section Bulk Materials and Their Main Applications is dedicated to the growing field of nanoscaled metal oxysulfides. Synthesis and applications of lanthanide-based nanoparticles are more mature and are discussed first. Then, works on transition-metal based nanoparticles are presented and discussed. Altogether, this review highlights the opportunities offered by metal oxysulfides for application in a range of technological fields, in relation with the most advanced synthetic routes and characterization techniques.

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Synthesis and characterization of physical properties of Gd2O2S:Pr3+ semi-nanoflower phosphor

Cited by 20 publications

References 23 publications

Thermal Stability of Oleate‐Stabilized Gd₂O₂S Nanoplates in Inert and Oxidizing Atmospheres

Thermal Stability of Oleate‐Stabilized Gd₂O₂S Nanoplates in Inert and Oxidizing Atmospheres

Photo/cathodoluminescence and stability of Gd₂O₂S:Tb,Pr green phosphor hexagons calcined from layered hydroxide sulfate

Metal Oxysulfides: From Bulk Compounds to Nanomaterials

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Synthesis and characterization of physical properties of Gd2O2S:Pr3+ semi-nanoflower phosphor

Cited by 20 publications

References 23 publications

Thermal Stability of Oleate‐Stabilized Gd2O2S Nanoplates in Inert and Oxidizing Atmospheres

Thermal Stability of Oleate‐Stabilized Gd2O2S Nanoplates in Inert and Oxidizing Atmospheres

Photo/cathodoluminescence and stability of Gd2O2S:Tb,Pr green phosphor hexagons calcined from layered hydroxide sulfate

Metal Oxysulfides: From Bulk Compounds to Nanomaterials

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Product

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About

Thermal Stability of Oleate‐Stabilized Gd₂O₂S Nanoplates in Inert and Oxidizing Atmospheres

Thermal Stability of Oleate‐Stabilized Gd₂O₂S Nanoplates in Inert and Oxidizing Atmospheres

Photo/cathodoluminescence and stability of Gd₂O₂S:Tb,Pr green phosphor hexagons calcined from layered hydroxide sulfate