Red emitting Y2O3:Eu3+ nanophosphors with > 80% down conversion efficiency

Obtaining nanophosphors of a controlled size and shape with a high quantum efficiency is the current challenge for display and imaging technologies. Although the surface state induced luminescence quenching in nanophosphors may be compensated to some extent by incorporating activators like rare-earth ions, or by exploiting their quantum size effect, obtaining nanophosphors with quantum efficiencies as high as their bulk counterparts remains elusive. In the present article, we report on the synthesis of uniform Eu-doped Y2O3 nanoparticles, with an average size of 20-53 nm and a down conversion efficiency as high as 85%, using a simple chemical precipitation technique. Along with size control, the effects of Eu3+ content on their emission behaviors have been discussed. We believe the low-cost synthesis process of these nanoparticles will greatly enhance their application potential in optical display and bio-imaging technologies.