Ultraviolet-TriggeredRed-Emitting NaEuF₄:Tb³⁺ Nanorods for WhiteLED

With the development of solid-state lighting technology, high-efficiency phosphors (especially red phosphors) for near-ultraviolet LEDs have become increasingly important. In this paper, red-emitting NaEuF₄:<i>x</i>Tb³⁺ nanorods were successfully synthesized using a sacrificial template method at 150 °C and pH ∼ 7.5, with layered europium hydroxide Eu₂(OH)₅NO₃·<i>n</i>H₂O nanosheets as the template precursor and NaF as an anion source. The phase transition mechanism from the precursor template to NaEuF₄:<i>x</i>Tb³⁺ was studied by varying the concentration ratio of the anion source to precursor template. Under the excitation at 394 nm, NaEuF₄:10%Tb³⁺ nanorods exhibit optimal red-emitting emission and excellent thermal stability. In addition, a near-ultraviolet chip-pumped white LED was successfully prepared by combining the prepared red-emitting NaEuF₄:10%Tb³⁺ with green-emitting (Sr, Ba)₂SiO₄:Eu²⁺ and blue-emitting BaMgAl₁₀O₁₇:Eu²⁺. The fabricated white LED can emit good color coordinates (0.32, 0.33), high color rendering index (93.4), and low correlation color temperature (6078 K). This work provides a simple method for the preparation in large quantity of NaEuF₄:<i>x</i>Tb³⁺ nanorods and may be extended to other types of luminescent nanomaterials.