Li₂O–Al₂O₃–ZnO–P₂O₅:Dy³⁺/Sm³⁺/Eu³⁺ glasses for solid-state yellow laser and color tunable phosphor applications

Abstract

Laser and optical properties (absorbance, excitation/emission and decay time data) of Dy³⁺, Dy³⁺/Sm³⁺, Dy³⁺/Sm³⁺/Eu³⁺-doped Li₂O–Al₂O₃–ZnO–P₂O₅ glasses are investigated. Laser spectroscopic parameters of the dysprosium yellow emission show potentialities of the luminescent glass as yellow laser medium under excitation at 348 nm. The Dy³⁺/Sm³⁺-activated glass tonality can be shifted from neutral white of 4559 K under 350 nm excitation to yellowish-orange of 2033 K (85.3% color purity) upon 372 nm excitation. A shortening of the dysprosium ⁴F_9/2 level lifetime revealed that Sm³⁺ can be sensitized by Dy³⁺ by means of a non-radiative energy transfer that could be occurring into Dy³⁺–Sm³⁺ clusters with an efficiency of 0.13. The Dy³⁺/Sm³⁺/Eu³⁺-activated glass tonality can be shifted from warm white of 3387 K under 350 nm excitation to reddish-orange of 1638 K (92.1% color purity) upon 372 nm excitation. From lifetime data of the Dy³⁺ ion ⁴F_9/2 and Sm³⁺ ion ⁴G_5/2 levels is inferred that non-radiative energy transfers from dysprosium to europium and/or samarium and from samarium to europium could be occurring into Dy³⁺–Sm³⁺–Eu³⁺ clusters with energy transfer efficiencies of 0.22 and 0.41, respectively.