Preparation and cathodoluminescence characteristics of rare earth activated BaAl2O4 phosphors
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Date
2018
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Abstract
Undoped and Pr, Sm and Tb activated BaAl2O4 phosphors have been synthesized by solid state reaction method and combustion method. The structure and morphological observation of the phosphor samples were monitored by X-ray powder diffraction (XRD) and environmental scanning electron microscope (ESEM) coupled to an energy dispersive X-ray spectrometer (EDS). The all diffraction peaks are well assigned to standard data card (PDF♯17–306). Emission properties of the samples were explored using light emission induced by an electron beam (i.e cathodoluminescence, CL) at room temperature (RT). Undoped BaAl2O4 sample exhibits a broad defect emission from 300 to 500 nm from the aluminate defect centres. CL spectra recorded at room temperature display that the as-prepared BaAl2O4:Ln (Ln=Pr, Sm and Tb) phosphors exhibit different luminescence colors coming from different rare earth activator ions. The transition 4G5/2 → 6H7/2 located at 606 and 610 nm for Sm3+ can occur as hypersensitive transition having the selection rule ΔJ = ± 1. For the Tb3+ doped samples, they exhibit D45 green line emissions. The proposed luminescent mechanisms of all doped rare earth ions are also discussed. © 2018 Elsevier Ltd
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Aluminum compounds , Cathodoluminescence , Defects , Diffraction , Metal ions , Phosphors , Praseodymium compounds , Rare earths , Samarium , Scanning electron microscopy , Sodium Aluminate , Solid state reactions , Spectrometers , X ray powder diffraction , X ray spectrometers , X rays , barium aluminate , barium derivative , lanthanide , unclassified drug , BaAl2O4 , Energy dispersive x-ray spectrometers , Environmental scanning electron microscopes , Hypersensitive transitions , Luminescent mechanism , Morphological observations , Rare-earth activators , Solid state reaction method , Article , cathodoluminescence , controlled study , electron beam , energy dispersive X ray spectroscopy , environmental scanning electron microscopy , luminescence , priority journal , room temperature , scanning electron microscopy , stoichiometry , synthesis , X ray powder diffraction , Barium compounds