Analysis of Judd-Ofelt parameters and radioluminescence results of SrNb2O6:Dy3+phosphors synthesizedviamolten salt method
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2020
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Abstract
In this work, Dy3+-doped SrNb2O6phosphors were fabricated by the molten salt process, which avoids high sintering temperatures, prolonged reaction time and poor compositional homogeneity. All samples crystallized to the orthorhombic columbite structure with space group,P21/c, while a rod-like morphology was observed by scanning electron microscopy (SEM). PL (photoluminescence) and RL (radioluminescence) spectra of SrNb2O6:Dy3+exhibited a strong blue emission peak at 576.0 nm related to4F9/2→6H15/2transition of Dy. The high RL emission of the4F9/2→6H15/2(electric dipole) transition upon X-ray-induced excitation led to a decrease in Dy3+local environmental symmetry. The Judd-Ofelt (J-O) theory was applied to the PL excitation spectra for the calculation of optical data such asΩ2,Ω4, andΩ6parameters, radiative transition probability (Ar), branching ratios (β,βexp) and stimulated emission cross-section (σe). The quantum efficiencies (ηQE) varied between 35.47 and 31.93%, which are compatible with theoretical quantum efficiencies based on the Einstein relation. The CIE chromaticity coordinates (x,y) and CCT (correlated color temperature) parameter for 3 mol% phosphor were defined (0.385, 0.432) and 4209 K, respectively. © the Owner Societies 2020.
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Efficiency , Electric excitation , Judd-Ofelt theory , Light emission , Phosphors , Scanning electron microscopy , Semiconductor quantum wells , Columbite structure , Compositional homogeneity , Correlated color temperature , High sintering temperatures , Judd-Ofelt parameters , Radiative transition probabilities , Rod-like morphology , Stimulated emission cross section , Quantum efficiency