Luminescence properties and energy transfer behavior of Dy3+/Tm 3+ co-doped phosphate glasses with high moisture-resistance and thermal stability for W-LEDs

A series of Dy3+/Tm3+ single- and co-doped phosphate glasses with high moisture resistance and thermal stability was prepared by a conventional melt-quenching method. Under 365-nm ultraviolet (UV) light excitation, a white light with a chromatic coordinate of (0.3300, 0.3439), which is very close to the standard white light, could be obtained. The luminescence characteristics and energy transfer mechanism between the Dy3+ and Tm3+ ions were studied, and the fluorescence lifetime revealed the existence of the energy transfer processes. Furthermore, the Dy3+/Tm3+ co-activated glasses exhibited high moisture resistance, the emission peaks of 450, 480 and 572 nm remained at the original intensity of 99.2%, 99.9% and 99.9% of its original intensity after immersion in water for 120 h. At the same time, the luminescence intensity of the sample at 500 K can be maintained at a minimum of 85% of its intensity at room temperature, indicating the good thermal stability of the glasses. Overall, the prepared phosphate glasses have the potential to be applied in UV-based white-light-emitting diodes.