【Others Papers】Enhanced photoluminescence and thermal stability in tri-doped Ga₂O₃:Eu³⁺/Dy³⁺/Ti⁴⁺ phosphors via energy transfer mechanisms

      Researchers from the Guangzhou University have published a dissertation titled "Enhanced photoluminescence and thermal stability in tri-doped Ga₂O₃:Eu³⁺/Dy³⁺/Ti⁴⁺ phosphors via energy transfer mechanisms" in Journal of the European Ceramic Society.

Abstract

      Rare-earth (RE)-doped Ga₂O₃ has promising applications in light-emitting devices. Herein, a systematic experimental study was conducted to investigate the photoluminescence (PL) properties of Ga₂O₃ semiconductor as a function of dopant type and concentration, including single-doped (Ga₂O₃:xEu³⁺, Ga₂O₃:yDy³⁺), co-doped (Ga₂O₃:0.035Eu³⁺/0.01Dy³⁺), and tri-doped (Ga₂O₃:0.035Eu³⁺/0.01Dy³⁺/zTi⁴⁺) phosphor systems. Comprehensive PL measurements show that the doping concentration, sintering temperature, and time have a significant impact on the PL emission intensity and chromaticity. The optimal synthesis parameters were determined for each phosphor system: Ga₂O₃:xEu³⁺ (x = 0.035, 1300°C, 8h), Ga₂O₃:yDy³⁺ (y = 0.01, 1500°C, 8h), and Ga₂O₃:0.035Eu³⁺/0.01Dy³⁺/zTi⁴⁺ (z = 0.08, 1300°C, 8h). The optimized Ga₂O₃:0.035Eu³⁺ sample exhibits severe thermal quenching, with red emission intensity (∼613 nm) dropping to 16% at 500 K. However, co-doping with merely 1 mol% Dy³⁺ (Ga₂O₃:0.035Eu³⁺/0.01Dy³⁺) produces anomalous thermal enhancement, reaching 109% intensity at 420 K and maintaining 97% at 500 K. This remarkable improvement, maintaining 97% intensity at high temperatures versus 16% for the single-doped sample, is attributed to efficient Dy³⁺ → Eu³⁺ energy transfer that compensates for thermal quenching effects. Further incorporation of Ti⁴⁺ into Ga₂O₃:0.035Eu³⁺/0.01Dy³⁺/zTi⁴⁺ degrades the formation of the unwanted Eu₃Ga₅O₁₂ phase and enhances luminescence intensity. The red (613 nm), blue (484 nm), and yellow (573 nm) emissions of Eu³⁺ and Dy³⁺ are significantly enhanced by increased absorption at 394 nm and by efficient energy transfer from Ti⁴⁺ to both Eu³⁺ and Dy³⁺. CIE chromaticity analysis reveals that adding Dy³⁺ to Ga₂O₃:0.035Eu³⁺ substantially improves both emission coordinates and color purity across the measured temperature range. Collectively, these results demonstrate that the optimized co-doping of Dy^3 + /Ti⁴⁺ effectively enhances the overall luminescence performance of Ga₂O₃:Eu³⁺-based materials.

DOI：

https://doi.org/10.1016/j.jeurceramsoc.2026.118268