title: Study on low temperature solution combustion synthesized Sr(2)SiO(4):Dy(3+) nano phosphor for white LED.
abstract: A series of Dy(3+) (1-5mol.%) activated Sr2SiO4 nanophosphors were prepared by low temperature solution combustion method using oxalyl dihydrazide (ODH) as a fuel. The obtained phosphor was well characterized by powder X-ray diffraction, scanning electron microscopy, and UV-visible spectroscopy. The average crystallite sizes were estimated by Debye-Scherrer formula and Williamson-Hall plots and found to be in the range 20-32nm. Energy band gap was found to be widened with increase of Dy(3+) ion dopant. Photoluminescence spectra consist of three main groups of peaks in 460-500nm (blue), 555-610nm (yellow) and 677nm (red) respectively. These peaks were assigned to transition of (4)F9/2→(6)H15/2,13/2,11/2. The critical distance between Dy(3+) ions and quenching site was found to be ∼16.71Ǻ. The chromaticity co-ordinates of all the prepared phosphors were located in white light; as a result Dy(3+) activated Sr2SiO4 is a promising single phased phosphor for white light emitting diodes. Thermoluminescence (TL) of Dy(3+) doped Sr2SiO4 nanophosphors were investigated using γ-irradiation in the dose range 1-6kGy at a warming rate of 2.5°Cs(-1). The phosphors show a well resolved single glow peak at ∼145°C. The kinetic parameters were estimated by different methods and the results discussed. The TL intensity increases linearly with γ-dose at room temperature. The effect of fading with storage time was found to be ∼66% which is highly useful in radiation dosimetry.
authors.affiliation: Prof. C.N.R.Rao Centre for Advanced Materials, Tumkur University, Tumkur 572 103, India.
authors.forename: D V
authors.initials: DV
authors.lastname: Sunitha
authors.affiliation: Prof. C.N.R.Rao Centre for Advanced Materials, Tumkur University, Tumkur 572 103, India. Electronic address: bhushanvlc@gmail.com.
authors.forename: H
authors.initials: H
authors.lastname: Nagabhushana
authors.affiliation: Chhattisgarh Swamy Vivekananda Technical University, North Park Avenue, Sector - 8, Bhilai, Chhattisgarh 490 009, India.
authors.forename: S C
authors.initials: SC
authors.lastname: Sharma
authors.affiliation: Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054, India.
authors.forename: B M
authors.initials: BM
authors.lastname: Nagabhushana
authors.affiliation: Department of Physics, B.S. Narayan Centre of Excellence for Advanced Materials, B.M.S. Institute of Technology, Bangalore 560 064, India.
authors.forename: B
authors.initials: B
authors.lastname: Daruka Prasad
authors.affiliation: National Aerospace Laboratories (CSIR), Bangalore 560 017, India.
authors.forename: R P S
authors.initials: RP
authors.lastname: Chakradhar
mesh_terms: D049449:Luminescence; D053758:Nanoparticles / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D013324:Strontium / Q000737:chemistry*
chemical_list: D017640:Silicates; D013324:Strontium
keywords: Combustion method; Phosphor; Photoluminescence; Thermoluminescence; WLEDs