A series of emission-tunable LuF 3 :RE 3+ (RE = Dy, Tb, Eu, Tm) phosphors was first synthesized via a glutamic acid-assisted one-step hydrothermal process. X-ray diffraction and SEM characterizations confirmed that the products consisted of pure LuF., pure NaLuF., or their mixed phases, with morphologies (irregular particles, hexagonal prismatic tubes, microspheres, fusiform structures, leaf-like architectures, etc.) precisely tunable by adjusting the initial reaction pH (2.25–11.16) or the molar ratios of RE 3+ /NaF (1:1–1:11) and RE 3+ /NaBF 4 (1:1–1:11). The luminescent properties of Dy 3+ /Tb 3+ , Tb 3+ /Eu 3+ , Dy 3+ /Eu 3+ , and Tm 3+ /Dy 3+ co-doped systems revealed characteristic emissions: Dy 3+ (482 nm, 575 nm), Tb 3+ (545 nm), Eu 3+ (590 nm, 616 nm), and Tm 3+ (454 nm). Tunable multicolor luminescence (blue, green, light yellow, white) was achieved by varying the excitation wavelength (317–394 nm) or dopant concentrations, as verified by CIE chromaticity coordinates ranging from (0.1881, 0.1933) to (0.3988, 0.3759). The facile synthesis route, controllable structure, and excellent luminescent performance make these LuF 3 :RE 3+ phosphors promising single-component materials for advanced optoelectronic applications such as displays and solid-state lighting.
Hongxia et al. (Thu,) studied this question.