LaNbO₄:RE3+ (RE = Dy, Dy/Sm, Sm) 형광체의 구조, 표면, 광학 특성

The effects of activator ion on the structural, morphological, and optical properties of LaNbO4:RE3+ (RE = Dy, Dy/Sm, Sm) phosphors were investigated. X-ray diffraction patterns exhibited that all the phosphors showed a monoclinic system with a main (112) diffraction peak, irrespective of the concentration and type of activator ions. The grain size showed a slightly decreasing tendency as the concentration of Sm3+ ions increased. The excitation spectra of the LaNbO4:Dy3+, Sm3+ phosphor powders consisted of a strong charge transfer band centered at 259 nm in the range of 220–290 nm and five weak peaks. The emission spectra of the La0.95NbO4:5 mol% Dy3+ phosphors exhibited an intense two yellow and blue bands centered at 575 nm and 479 nm respectively, which resulted from the 4F9/2→6H13/2 and 4F9/2→6H15/2 transitions of Dy3+. As the concentration of Sm3+ was increased, the intensity of the yellow emission band was gradually decreased, while those of orange and red emission bands centered at 604 and 646 nm began to appear and reached maxima at 5 mol%, and then decreased rapidly with further increases in the Sm3+ concentration. These results indicated that white light emission could be realized by controlling the concentrations of the Dy3+ and Sm3+ ions incorporated into the LaNbO4 host crystal. KCI Citation Count: 0