Sodium zinc phosphate glasses doped with Tb3+ and Tb3+/Eu3+ as multicolor phosphor for green laser stimulated emission and WLED applications

Abstract

Sodium zinc phosphate glasses doped with Tb3+ and Tb3+/Eu3+ were synthesized by the melt quenching method. Spectroscopic properties of the these glasses were analyzed to investigate their suitability as multicolor phosphor for green laser stimulated emission and WLED applications. In the 1.0 mol% Tb2O3 doped sodium zinc phosphate glass, the 5D4→7F5 green transition exhibits gain linewidth and optical gain values larger than those reported in other phosphate glasses doped with the same terbium content. The tonality of emitting light from the glass singly doped with terbium shifts from green to bluish-white and greenish-white as Tb2O3 content decreases from 2.0–2.5 mol% to 0.5–1.0 mol% under excitation at 350 nm. A 574 nm yellow tonality, close to warm-white one of 3564 K, is attained in the co-doped glass, wherein the europium emission is sensitized through the terbium excitation at 340 nm. The co-doped glass can also emit 591 nm orange light and 609 nm reddish-orange light, with color purities above 93 %, under Tb3+/Eu3+ (377 nm) and Eu3+ (393 nm) excitations, respectively.