Luminescent properties of Dy3+ activated LaMgAl11O19 yellow emitting phosphors for application in white-LEDs

Abstract A series of Dy3+-doped LaMgAl11O19 (Dy: LMA) phosphors were prepared by the solid state reaction method. The band structure and density of states of LaMgAl11O19 were calculated. The crystalline structures were investigated by X-ray diffraction and transmission electron microscopy. The chemical elements of Dy: LMA phosphors were characterized by energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. All the Dy: LMA phosphors exhibit intense yellow emissions at 573 nm under the excitation of 449 nm. Based on the measured absorption, emission spectra and the fluorescence decay curves, as well as the discussion and comparison of their spectral parameters, the optimal doping concentration of Dy3+ in LMA is confirmed to be 4 at.%. The Commission International del’Eclairage (CIE) 1931 chromaticity coordinates of all the samples were located in the yellow region. The mechanism of concentration quenching of Dy3+ in LMA was discussed.