Synthesis and luminescent behavior of Dy:Y3Ga5O12 phosphor for UV induced white LEDs

The synthesis, X-ray diffraction (XRD) pattern, excitation spectrum, emission spectra and decay times were studied for the first time to our best knowledge. The Dy:Y3Ga5O12 (Dy:YGG) phosphors with Dy3+ ions concentration of 0.5%, 1%, 3%, 5% and 10% were prepared by sol-gel method. The XRD patterns show that the phosphors possess perfect YGG phase. The average particle size of the Dy:YGG phosphors was calculated to be about 40 nm. The strongest excitation peak was 353 nm, which is favorable to ultra violet (UV) induced white light-emitting diodes (LEDs). Three emission bands centered at 480 nm, 580 nm and 672 nm could be observed under excitation of 353 nm. The yellow-to-blue integrated intensity ratios (Y/B) were 1.4-1.7 for the Dy3+ ions concentrations from 0.5 to 5%. The optimum Dy3+ concentration is 3%, and the corresponding 1931 Commission International de I'Eclairage (CIE) coordinates is (x = 0.37, y = 0.38). The results show that Dy:YGG phosphors can be a good candidate for UV-excitation warm-yellowish-white LEDs.