Spectral and surface investigations of Ca2V2O 7:Eu3+ nanophosphors prepared by citrate-gel combustion method: A potential red-emitting phosphor for near-UV light-emitting diodes

Vinay Kumar, A. K. Bedyal, J. Sharma, V. Kumar, O. M. Ntwaeaborwa, H. C. Swart

Research output: Contribution to journalArticlepeer-review

30 Citations (Scopus)

Abstract

In the present work, red-emitting Ca2V2O 7:xEu3+ (x = 0.5-6.0 mol%) nanophosphors, in the form of powders, were synthesized by the citrate-gel combustion method using metal nitrates as precursors and citric acid as fuel. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy, photoluminescence (PL) and cathodoluminescence (CL) spectroscopy were used to study the structure, morphology and spectral properties of the samples. The chemical compositions and electronic states of the powders were analyzed with X-ray photoelectron spectroscopy. The average crystallite sizes estimated using the XRD data were found to be in the range of 30-45 nm, and were cross verified by TEM. The lattice parameters determined by the POWD program were approximated as a = 7.242 Å, b = 6.674 Å, c = 6.932 Å and V = 291.24 Å3, respectively. Under UV (395 nm) (PL) and electron (CL) excitation, the nanophosphors show characteristic emission from the Eu 3+ ion (5D07Fj, j = 1-5) with the main peaks at 612 and 616 nm. The maximum emission intensity was recorded from the sample with an Eu3+ concentration of 4 mol% and a critical energy distance of 19.084 Å between the donor and the acceptor. Above this concentration, there was a reduction in the intensity due to dipole-dipole induced concentration quenching effects. The potential applications of this phosphor as a high color-purity phosphor in light-emitting diodes are evaluated.

Original languageEnglish
Pages (from-to)1785-1792
Number of pages8
JournalApplied Physics A: Materials Science and Processing
Volume116
Issue number4
DOIs
Publication statusPublished - Sept 2014
Externally publishedYes

ASJC Scopus subject areas

  • General Chemistry
  • General Materials Science

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