A Strategy to Achieve Efficient Dual-Mode Luminescence of Eu3+ in Lanthanides Doped Multifunctional NaGdF4 Nanocrystals

A strategy is proposed to fabricate dual-mode luminescent NaGdF4 nanocrystals that are composed of NaGdF4:Yb3+,Tm3+ core and NaGdF4:Eu3+ shell. Intense downconversion via the sensitization of Gd3+ and upconversion luminescence of Eu3+ that is one order of magnitude higher than the triply-doped core only counterparts have been achieved by employing the distinct core/shell nanostructures and double sensitizations of Yb3+ and Tm3+.