Selective Synthesis and Luminescence Properties of Nanocrystalline GdF3:Eu 3+ with Hexagonal and Orthorhombic Structures

GdF 3 :Eu 3+ nanophosphors with hexagonal or orthorhombic structure have been succeeded to be selectively synthesized at room temperature for the first time via a simple soft chemical route. The structure and morphology of GdF 3 :Eu 3+ nanophosphors were controlled by using different fluoride precursors. Hexagonal GdF 3 :Eu 3+ nanocrystals were formed when NaBF 4 was used as a fluoride precursor, while orthorhombic GdF 3 :Eu 3+ nanocrystals were obtained with NaF or NH 4 F fluoride precursor. It was also experimentally revealed that hexagonal GdF 3 :Eu 3+ nanophosphors emitted essentially stronger Eu 3+ luminescence than orthorhombic ones did. The formation mechanism of GdF 3 nanocrystals and the possible reasons of the strong PL in hexagonal were discussed.