Crystal Structure and Luminescence Properties of Rare Earth Doped Ba2Bi2/3TeO6 Double Perovskites. (2017)

• Record Type: Journal Article
• Authors: Lal, Sariga C.; Rajan, Athira; Subodh, G.
• Is Part Of: Materials today. Volume 4:Number 2(2017)Part C
• Page Start: 4396
• Page End: 4402
• Publication Date: 2017
• Subjects: Double Perovskites -- host material -- Luminescent centers -- Chromaticity Diagram; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2017.04.011
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: Recently there has been an increase in demand for inorganic phosphors as it can be used in many of solid-state lighting devices. A number of perovskite materials especially vanadates, molybdates, and tungstates, can act as host lattices for rare earth ions. These host lattices can efficiently absorb ultraviolet light through the excitation of the charge-transfer state and can transfer the absorbed energy to the activator. In the present study, we investigate the crystal structure and luminescent properties of pure and rare earth doped Ba2 Bi2/3 TeO6 showing 1:1 rock salt ordering. The compounds were synthesised using solid-state ceramic route. Ba2 Bi2/3 TeO6 crystallises in Fm 3 ¯ m symmetry with lattice parameter of 8.48Å. FT Raman and FT IR spectroscopic studies also confirm a cubic perovskite structure for Ba2 Bi2/3 TeO6 with 1:1 ordering of Bi 3+ and Te 6+ ions. Optical band gap of Ba2 Bi2/3 TeO6 double perovskites obtained through using UV-Visible absorption spectroscopy is about 2.8 eV. Photo luminescence properties of Ba2 Bi2/3-x REx TeO6 (RE=Eu, Dy, x=0.025, and 0.05) were also investigated. Eu 3+ and Dy 3+ doped samples show emission in orange-red region of the electromagnetic spectrum.