Photoluminescence properties of Dy3+/Eu3+ co-doped La2O3–Ga2O3 glasses synthesized via aerodynamic levitation furnace

A series of La 2 O 3 -Ga 2 O 3 -0.08Eu 2 O 3 - x Dy 2 O 3 amorphous samples ( x  = 0–0.14, interval of 0.01) were synthesized via containerless solidification. XRD results demonstrated that the prepared materials possessed an amorphous structure with a broad diffraction hump instead of sharp crystalline peaks. Differential thermal analysis (DTA) revealed that Dy 2 O 3 doping barely altered the glass transition temperature ( T g ) but significantly increased thermal stability and crystallization characteristic temperature ( T x ) and thermal stability parameter Δ T ( T x - T g ), with the maximum Δ T reaching ∼96 °C at x  = 0.09. Concentration quenching of Dy 3+ was dominated by multipolar interaction, confirmed by a critical distance ( R c ) of 18.98 Å and Dexter theory analysis. The optical band gap ( E opt ) remained ∼3.72 eV at x  ≤ 0.06 and decreased to ∼3.42 eV at x  = 0.11. CIE standard 1931 chromaticity coordinate values together with correlated color temperature (CCT) were tunable, with emission color evolving from warm reddish-orange to orange-yellow (CCT: 2250–3240 K). The excellent thermal stability, tunable PL, and tunable CCT render these amorphous materials promising candidates for solid-state luminescent devices.