White/orange tunable light emitting and energy transfer of Dy3+/Sm3+ dual-doped silicophosphate oxyfluoride glasses for photonic devices

Abstract

Silicophosphate oxyfluoride glasses by co-doping of Dy₂O₃ (Dy³⁺:0.5 mol%) with Sm₂O₃ (Sm³⁺:0.0, 0.1, 0.5, 1.0, 2.0, and 4.0 mol%) have been prepared using a melt and sudden quenching processes. The existence of Dy³⁺ (⁶H_15/2) and Sm³⁺(⁶H_5/2) peaks was studied via optical absorption spectra in the 280˗1800 nm region. The emission spectra of the glasses were excited under two excitation wavelengths (350 and 401 nm). This resulted in a decrease in the emission intensities (⁴F_9/2 → ⁶H_{15/2, 13/2, 11/2, 9/2}) of (Dy³⁺) and an increase in the emission intensities ⁴G_5/2 → ⁶H_{5/2, 7/2, 9/2, 11/2} of Sm³⁺. The energy transfer (ET) from Dy³⁺ to Sm³⁺ in current glasses results in a reduction of lifetime (Dy³⁺:⁴F_9/2) due to dipole-dipole interaction. The ET efficiencies of current glasses were found to be 0.75˗55.14 % with an increase of Sm³⁺ amounts. The radio luminescence (RL) spectra of current glasses were also studied under X-ray by applying a voltage of 50 kV and a current of 30 mA. This result showed the maximum scintillation efficiency of 16.85 % in the present 0.5Dy1.0Sm glass relative to the Bi₄Ge₃O₁₂ (BGO) crystal. The emission color of current glasses has been confirmed by CIE1931 chromaticity diagram, which has shown on natural white/yellow and orange region with 350 and 401 nm, respectively.