ZnGa2-xEuxO4 nanoparticles

10 minutes microwave synthesis, thermal tuning of Eu3+ site distribution and photophysical properties

Deepak Hebbar N., K. S. Choudhari, Nimai Pathak, S. A. Shivashankar, Suresh D. Kulkarni

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Microwave-assisted synthesis of red-emitting ZnGa2-xEuxO4 (x = 0.005, 0.008, 0.010, 0.012, 0.015) nanoparticles is reported. Salient features of this method are: 10 min are sufficient to obtain well-crystallized, phase-pure nanoparticles; synthesis upto 2 g/batch can be accomplished with high yields (>90%) at a low temperature of 200 °C; the obtained nanoparticles are near-spherical and of ∼7 nm size as seen by HR-TEM; as-prepared nanoparticles show intense red emission at 615 nm due to the 5D07F2 transition, when excited at 395 nm. The structural and optical properties of the ZnGa2-xEuxO4 were studied by XRD, HR-TEM, FE-SEM, FT-IR and time-resolved photoluminescence (PL) spectroscopy. ZnGa1.99Eu0.01O4 nanoparticles, which showed the most intense red emission, were studied for the effect of annealing (in air) on their optical properties. Annealing at up to 1000 °C (i) enhanced crystallinity and the crystallite size increased from ∼7 nm in the as-prepared material to ∼46 nm (ii) enhanced emission intensity, and moved the CIE coordinates towards red. Photoluminescence decay curves displayed two lifetimes, implying the distribution of Eu3+ (i) on particle surface (ii) within the host lattice; the distribution gradually changes with annealing. The peak fitting of the emission spectra implies C2v site symmetry around Eu3+. A detailed Judd–Ofelt analysis has been presented. The samples annealed at 600–800 °C showed ∼58% quantum efficiency. The color purity could be increased to 87% by varying the Eu3+ content. Our report demonstrates the efficacy of swift microwave-assisted synthesis (10 min) in providing a red phosphor of high color purity suitable for LEDs and display applications.

Original languageEnglish
Pages (from-to)676-685
Number of pages10
JournalJournal of Alloys and Compounds
Volume768
DOIs
Publication statusPublished - 05-11-2018

Fingerprint

Tuning
Microwaves
Nanoparticles
Annealing
Optical properties
Transmission electron microscopy
Color
Photoluminescence spectroscopy
Crystallite size
Quantum efficiency
Phosphors
Light emitting diodes
Structural properties
Photoluminescence
Display devices
Hot Temperature
Scanning electron microscopy
Air
Temperature

All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Cite this

@article{4f082de659a54a89969c75635d27ca90,
title = "ZnGa2-xEuxO4 nanoparticles: 10 minutes microwave synthesis, thermal tuning of Eu3+ site distribution and photophysical properties",
abstract = "Microwave-assisted synthesis of red-emitting ZnGa2-xEuxO4 (x = 0.005, 0.008, 0.010, 0.012, 0.015) nanoparticles is reported. Salient features of this method are: 10 min are sufficient to obtain well-crystallized, phase-pure nanoparticles; synthesis upto 2 g/batch can be accomplished with high yields (>90{\%}) at a low temperature of 200 °C; the obtained nanoparticles are near-spherical and of ∼7 nm size as seen by HR-TEM; as-prepared nanoparticles show intense red emission at 615 nm due to the 5D0 → 7F2 transition, when excited at 395 nm. The structural and optical properties of the ZnGa2-xEuxO4 were studied by XRD, HR-TEM, FE-SEM, FT-IR and time-resolved photoluminescence (PL) spectroscopy. ZnGa1.99Eu0.01O4 nanoparticles, which showed the most intense red emission, were studied for the effect of annealing (in air) on their optical properties. Annealing at up to 1000 °C (i) enhanced crystallinity and the crystallite size increased from ∼7 nm in the as-prepared material to ∼46 nm (ii) enhanced emission intensity, and moved the CIE coordinates towards red. Photoluminescence decay curves displayed two lifetimes, implying the distribution of Eu3+ (i) on particle surface (ii) within the host lattice; the distribution gradually changes with annealing. The peak fitting of the emission spectra implies C2v site symmetry around Eu3+. A detailed Judd–Ofelt analysis has been presented. The samples annealed at 600–800 °C showed ∼58{\%} quantum efficiency. The color purity could be increased to 87{\%} by varying the Eu3+ content. Our report demonstrates the efficacy of swift microwave-assisted synthesis (10 min) in providing a red phosphor of high color purity suitable for LEDs and display applications.",
author = "{Hebbar N.}, Deepak and Choudhari, {K. S.} and Nimai Pathak and Shivashankar, {S. A.} and Kulkarni, {Suresh D.}",
year = "2018",
month = "11",
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doi = "10.1016/j.jallcom.2018.07.308",
language = "English",
volume = "768",
pages = "676--685",
journal = "Journal of Alloys and Compounds",
issn = "0925-8388",
publisher = "Elsevier BV",

}

ZnGa2-xEuxO4 nanoparticles : 10 minutes microwave synthesis, thermal tuning of Eu3+ site distribution and photophysical properties. / Hebbar N., Deepak; Choudhari, K. S.; Pathak, Nimai; Shivashankar, S. A.; Kulkarni, Suresh D.

In: Journal of Alloys and Compounds, Vol. 768, 05.11.2018, p. 676-685.

Research output: Contribution to journalArticle

TY - JOUR

T1 - ZnGa2-xEuxO4 nanoparticles

T2 - 10 minutes microwave synthesis, thermal tuning of Eu3+ site distribution and photophysical properties

AU - Hebbar N., Deepak

AU - Choudhari, K. S.

AU - Pathak, Nimai

AU - Shivashankar, S. A.

AU - Kulkarni, Suresh D.

PY - 2018/11/5

Y1 - 2018/11/5

N2 - Microwave-assisted synthesis of red-emitting ZnGa2-xEuxO4 (x = 0.005, 0.008, 0.010, 0.012, 0.015) nanoparticles is reported. Salient features of this method are: 10 min are sufficient to obtain well-crystallized, phase-pure nanoparticles; synthesis upto 2 g/batch can be accomplished with high yields (>90%) at a low temperature of 200 °C; the obtained nanoparticles are near-spherical and of ∼7 nm size as seen by HR-TEM; as-prepared nanoparticles show intense red emission at 615 nm due to the 5D0 → 7F2 transition, when excited at 395 nm. The structural and optical properties of the ZnGa2-xEuxO4 were studied by XRD, HR-TEM, FE-SEM, FT-IR and time-resolved photoluminescence (PL) spectroscopy. ZnGa1.99Eu0.01O4 nanoparticles, which showed the most intense red emission, were studied for the effect of annealing (in air) on their optical properties. Annealing at up to 1000 °C (i) enhanced crystallinity and the crystallite size increased from ∼7 nm in the as-prepared material to ∼46 nm (ii) enhanced emission intensity, and moved the CIE coordinates towards red. Photoluminescence decay curves displayed two lifetimes, implying the distribution of Eu3+ (i) on particle surface (ii) within the host lattice; the distribution gradually changes with annealing. The peak fitting of the emission spectra implies C2v site symmetry around Eu3+. A detailed Judd–Ofelt analysis has been presented. The samples annealed at 600–800 °C showed ∼58% quantum efficiency. The color purity could be increased to 87% by varying the Eu3+ content. Our report demonstrates the efficacy of swift microwave-assisted synthesis (10 min) in providing a red phosphor of high color purity suitable for LEDs and display applications.

AB - Microwave-assisted synthesis of red-emitting ZnGa2-xEuxO4 (x = 0.005, 0.008, 0.010, 0.012, 0.015) nanoparticles is reported. Salient features of this method are: 10 min are sufficient to obtain well-crystallized, phase-pure nanoparticles; synthesis upto 2 g/batch can be accomplished with high yields (>90%) at a low temperature of 200 °C; the obtained nanoparticles are near-spherical and of ∼7 nm size as seen by HR-TEM; as-prepared nanoparticles show intense red emission at 615 nm due to the 5D0 → 7F2 transition, when excited at 395 nm. The structural and optical properties of the ZnGa2-xEuxO4 were studied by XRD, HR-TEM, FE-SEM, FT-IR and time-resolved photoluminescence (PL) spectroscopy. ZnGa1.99Eu0.01O4 nanoparticles, which showed the most intense red emission, were studied for the effect of annealing (in air) on their optical properties. Annealing at up to 1000 °C (i) enhanced crystallinity and the crystallite size increased from ∼7 nm in the as-prepared material to ∼46 nm (ii) enhanced emission intensity, and moved the CIE coordinates towards red. Photoluminescence decay curves displayed two lifetimes, implying the distribution of Eu3+ (i) on particle surface (ii) within the host lattice; the distribution gradually changes with annealing. The peak fitting of the emission spectra implies C2v site symmetry around Eu3+. A detailed Judd–Ofelt analysis has been presented. The samples annealed at 600–800 °C showed ∼58% quantum efficiency. The color purity could be increased to 87% by varying the Eu3+ content. Our report demonstrates the efficacy of swift microwave-assisted synthesis (10 min) in providing a red phosphor of high color purity suitable for LEDs and display applications.

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