Enhanced Luminescence of NaY_0.6–xCe_0.1Gd_0.3Eu_xF₄ Nanorods by Energy Transfers between Ce³⁺, Gd³⁺, and Eu³⁺

In this study, hexagonal-phase NaY 0.6– x Ce 0.1 Gd 0.3 Eu x F 4 nanorods were synthesized via a mild solvothermal method. By modifying the Eu 3+ dopant concentration, the crystal phase, morphology, and luminescent properties were well controlled. A broad excitation band centered at around 260 nm corresponding to the 2 F 5/2 → 4f-5d transition of Ce 3+ was detected in the hosts containing Gd 3+ ions by monitoring the Eu 3+ emissions, indicating that an efficient Ce 3+ → Eu 3+ energy transfer occurred via the Gd 3+ sublattice. Luminescence decay behaviors of the NaY 0.6– x Ce 0.1 Gd 0.3 Eu x F 4 nanorods were studied, and the energy transfer mechanism was discussed. An obvious rising edge on the luminescence decay curve of Eu 3+ ions in the NaY 0.6– x Ce 0.1 Gd 0.3 Eu x F 4 nanorods was observed. The rising time is proposed to describe the energy migration time from Ce 3+ to Eu 3+ via the Gd 3+ sublattice.