Colloidal LaF_3:Yb,Er,LaF_3:Yb,Ho and LaF_3:Yb,Tm nanocrystals with multicolor upconversion fluorescence

摘要

The IR-to-visible upconversion fluorescent nanocrystals,Yb-Er,Yb-Ho and Yb-Tm co-doped LaF_3 were chemically synthesized and investigated.The ligand-capped nanocrystals were easily dispersed in organic solutions and subsequently formed a transparent colloidal solution.Under 980 nm IR excitation,green,red and blue emission bands were observed from these colloidal solutions,respectively.Compared with the recently reported colloidal NaYF_4:Yb,Er nanocrystals,our nanocrystals produced a fluorescence output which was 5 times higher.These nanocrystals have potential applications as bio-probes and displays.