Ultraviolet fluorescence of the Ce3+/Gd3+ co-doped NaYF4 nanocrystals

Abstract In this paper, Ce 3+ /Gd 3+ co-doped NaYF 4 nanocrystals were prepared via a traditional hydrothermal method using oleic acid as the stabilizing agent. Under 250 nm excitation, down-conversion emissions centered at 305 and 311 nm were observed in NaYF 4 :Ce 3+ /Gd 3+ nanocrystals. The down-conversion emissions were attributed to the 6 P 7/2 , 6 P 5/2 → 8 S 7/2 transitions of Gd 3+ ions. The energy transfer from Ce 3+ to Gd 3+ plays a crucial role in populating the excited energy levels of Gd 3+ ions.