NaLuF₄:RE³⁺ (Dy³⁺, Tb³⁺, Eu³⁺, Tm³⁺): controllable morphology, multicolor light

A series of emission-tunable NaLuF₄:RE³⁺ (RE = Dy, Tb, Eu, Tm) phosphors were firstly synthesized by a glycine assisted one-step hydrothermal process. The structure and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results revealed that the samples were Na₅Lu₉F₃₂, LuF₃ and NaLuF₄ and the size and shape of the products could be tuned just by adjusting the pH values of the initial reaction solutions or by adjusting the RE³⁺/NaF ratio or RE³⁺/NaBF₄ ratio. The morphologies for the products include irregular particles, irregular blocks, octahedral shapes, hexagons, or micron sized hexagonal prisms. Furthermore, the photoluminescence properties of NaLuF₄:Dy³⁺,Tb³⁺, NaLuF₄:Tb³⁺,Eu³⁺, NaLuF₄:Dy³⁺,Eu³⁺ and NaLuF₄:Tm³⁺,Dy³⁺ were investigated in detail. Additionally, when co-doping Dy³⁺ with Tb³⁺ or Eu³⁺ or co-doping Tb³⁺with Eu³⁺ or co-doping Tm³⁺ with Dy³⁺ ions in the single component, colorful emission can be obtained by giving abundant blue, green, yellow, orange, and especially white-light-emission. All these properties indicate that the developed phosphor may potentially be used as single-component multicolor-emitting phosphors.