A strategy to protect and sensitize near-infrared luminescent Nd3+ and Yb3+: organic tropolonate ligands for the sensitization of Ln(3+)-doped NaYF4 nanocrystals.

A strategy to sensitize and protect near-infrared (NIR) emitting Nd3+ and Yb3+ is presented. Combining protection provided by the inorganic matrix of NaYF4 nanocrystals and sensitization from tropolonate ligands capped on their surface, the lanthanide cation centered luminescence was observed through the ligand excitation. The extended lanthanide luminescence lifetimes indicate the success of this strategy.