Solid-state green light sources are desirable for high density optical storage

color displays

optoelectronics and medical diagnositics. So far

the conversion of infrared into visible has been extensively studied on various crystals. As one of rare earth ions that:emit up-conversion fluorescence

erbium gives rather high efficiency and is studied widely as an active ion. Preparation and luminescence properties of rare-earth oxides nanocrystals have been extensively studied. However

up to now

fewer articles have been reported about rare-earth fluoride nanocrystals. In this report

fabrication of rare-earth fluoride nanocrytals YF

3

:Er

3+

is reported in details. Based on the rare-earth oxides nanocrystals obtained by combustion synthesis

the YF

3

:Er

3+

nanocrytals were prepared through fluoridizing reaction at 400℃. The samples were characterized by XRD. Under the LD excitation (=980 nm)

the sample presents up-conversion luminescence with an intense green emission peaked at 547nm which belongs to the transition from

4

S

3/2

4

I

15/2

of Er ion and a week red emission peaked at 660nm from

4

F

9/2

4

I

5/2

transition. The green emission prevails over the red one due to the lower doping concentration and the lower phonon energy.