Study of luminescence properties of dysprosium-doped CaAl12 O19 phosphor for white light-emitting diodes.

ABSTRACT

Dy3+ -doped CaAl12 O19 phosphors were synthesized utilizing a combustion method. Crystal structure and morphological examinations were performed respectively using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques to identify the phase and morphology of the synthesized samples. Fourier transform infrared spectroscopy (FTIR) estimations were carried out using the KBr method. Photoluminescence properties (excitation and emission) were recorded at room temperature. CaAl12 O19Dy3+ phosphor showed two emission peaks respectively under a 350-nm excitation wavelength, centered at 477 nm and 573 nm. Dipole-dipole interaction via nonradiative energy shifting has been considered as the major cause of concentration quenching when Dy3+ concentration was more than 3 mol%. The CIE chromaticity coordinates positioned at (0.3185, 0.3580) for the CaAl12 O190.03Dy3+ phosphor had a correlated color temperature (CCT) of 6057 K, which is situated in the cool white area. Existing results point out that the CaAl12 O190.03Dy3+ phosphor could be a favorable candidate for use in white light-emitting diodes (WLEDs).