Synthesis of novel Dy 3+ activated Ba 2 CaZn 2 Si 6 O 17 phosphors for white light-emitting diodes.

Dysprosium ion (Dy3+ ) activated Ba2 CaZn2 Si6 O17 phosphors were synthesized using high temperature solid-state reaction method. Powder X-ray diffraction (PXRD) analysis confirmed the phase formation of the as-prepared phosphors. Scanning electron microscopy (SEM) analysis disclosed an agglomeration of particles with an irregular morphology. Under 350 nm excitation, the emission spectrum of Dy3+ ions showed bands at 481 nm (blue), 577 nm (yellow) and 674 nm (red). The influence of the Dy3+ concentration on its emission intensity was investigated. The optimum concentration of Dy3+ ions in the Ba2 CaZn2 Si6 O17 :Dy3+ phosphors were found to be x = 0.06. The critical energy transfer distance was calculated. The fluorescence lifetime was also determined for Ba2 CaZn2 Si6 O17 :0.06Dy3+ . The Commission International deI'Eclairage (CIE) chromaticity coordinates of the phosphor were calculated to be x = 0.304, y = 0.382. The activation energy for the thermal quenching was calculated to be 0.168 eV. These results indicated that the Ba2 CaZn2 Si6 O17 :Dy3+ phosphor might be a potential candidate for near ultraviolet (NUV)-based white light-emitting diodes.