Mild molten-salt synthesis and photoluminescence property of LaF3 and its white-light emission with Eu doping

Mild molten salt synthesis (MSS) method was utilized to synthesize rare earth fluorides nanocrystals with favorable fluorescence efficiency. LaF 3 nanocrystals were achieved through this modified MSS method by only using La(NO 3 ) 3 ·6H 2 O and NH 4 HF 2 as starting materials. NH 4 HF 2 is difunctionality as both fluorine source and the flux. The effects of reaction time and temperature to the synthesis of LaF 3 nanocrystals were discussed in detail. The fluorescence of LaF 3 nanocrystals was detected with excitation wavelength of 360   nm, the results showed a broad band emission centered at 475   nm. The photoluminescence properties of pure LaF 3 nanocrystals and Eu 3+ doped samples were also investigated. In our work, white light emission was achieved in single element (Eu 3+ ) doped LaF 3 nanocrystals by adjusting the concentration of Eu 3+ ions. This would be the combination of broad emission of LaF 3 nanocrystals and sharp line emission of Eu 3+ in the LaF 3 :Eu 3+ nanocrystals.