Cold and warm white light generation using Zn(PO3)2 glasses activated by Ce3+, Dy3+ and Mn2+

The photoluminescence of zinc metaphosphate glasses activated by Dy3+, Ce3+/Dy3+ and Ce3+/Dy3+/Mn2+ ions was investigated. Non-radiative energy transfers from Ce3+ to Dy3+ and Ce3+ to Mn2+ are observed upon 280 nm excitation. The non-radiative nature of these transfers is inferred from the increase in the decay rate of the Ce3+ emission when the glass is co-doped with Dy3+ or Dy3+/Mn2+. It is demonstrated that zinc metaphosphate glasses can generate cold or warm white light emission when they are doped with Ce3+/Dy3+ or Ce3+/Dy3+/Mn2+ and pumped at 280 nm (peak emission wavelength of AlGaN-based LEDs). The CIE1931 chromaticity coordinates and color temperature were (0.34, 0.35) and 5250 K for the cold light, and (0.47, 0.43) and 2700 K for the warm light.