Author/Authors :
Wang، نويسنده , , Guofeng and Qin، نويسنده , , Weiping and Wei، نويسنده , , Guodong and Wang، نويسنده , , Lili and Zhu، نويسنده , , Peifen and Kim، نويسنده , , Ryongjin and Zhang، نويسنده , , Daisheng and Ding، نويسنده , , Fuheng and Zheng، نويسنده , , Kezhi، نويسنده ,
Abstract :
YF3:Yb3+(20%)/Tm3+(2%) octahedral nanocrystals were synthesized by a microemulsion method with NH4HF2. Pumped with a 980-nm diode laser, the nanocrystals emitted weak blue and intense ultraviolet light. Especially, unusual 3P2 → 3H6 (∼265 nm) and 3P2 → 3F4 (∼309 nm) emissions, coming from a five-photon excitation process, were observed. The emissions from 1D2 and 1I6 were much stronger than those from 1G4 and 3H4. The upconversion mechanism was discussed in detail.
Keywords :
nanocrystals , Rare earth , Upconversion , Luminescence
