Comparative study of Eu3+ -activated LnOCl (Ln=La and Gd) phosphors and their Judd-Ofelt analysis

Dhananjaya, N and Shivakumara, C and Saraf, Rohit and Behera, Sukanti and Nagabhushana, H (2015) Comparative study of Eu3+ -activated LnOCl (Ln=La and Gd) phosphors and their Judd-Ofelt analysis. In: JOURNAL OF RARE EARTHS, 33 (9). pp. 946-953.

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Abstract

Eu3+-activated layered LnOCl (Ln=La and Gd) phosphors were synthesized by the conventional solid-state method at relatively low temperature (700 degrees C) and shorter duration of 2 h. The structural parameters were refined by the Rietveld refinement analysis and confirmed by the high resolution transmission electron microscopy (HRTEM). Both the compounds were crystallized in the tetragonal structure with space group P4/nmm (No. 129). The homogeneity of the elements were analyzed by TEM mapping and found to be uniformly distributed. The photoluminescence spectra revealed that the intensity of D-5(0)-> F-7(2) transition (619 nm) was more intense in Eu3+-activated GdOCl compared to LaOCl. This was due to the property of Gd3+ ions to act as an intermediate sublattice to facilitate the energy transfer to Eu3+ ions. Intensity parameters and radiative properties such as transition probabilities, radiative lifetime and branching ratio were calculated using the Judd-Ofelt theory. The CIE color coordinates result revealed that the Eu3+-activated GdOCl (0.641, 0.354) phosphor was close to the commercial red phosphors like, Y2O3:Eu3+ (0.645, 0.347), (Y2OS)-S-2:Eu3+ (0.647, 0.343) and National Television System Committee (NTSC) (0.67, 0.33). The results suggest that the present GdOCl:Eu3+ compound acts as a potential candidate for red phosphor materials.

Item Type:	Journal Article
Publication:	JOURNAL OF RARE EARTHS
Publisher:	ELSEVIER SCIENCE BV
Additional Information:	Copy right for this article belongs to the ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Keywords:	LaOCl; GdOCl; phosphors; Judd-Ofelt; CIE; rare earths
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	30 Oct 2015 06:57
Last Modified:	30 Oct 2015 06:57
URI:	http://eprints.iisc.ac.in/id/eprint/52652

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