Quantum Dot-Based Sensitization System for Boosted Photon Absorption and Enhanced Second Near-Infrared Luminescence of Lanthanide-Doped Nanoparticle.

Efficient energy transfer is a promising strategy in overcoming the inherent limits of a narrow band and weak absorption of lanthanide ions due to the nature of 4f-4f transitions. Herein, we introduce a nanoparticle-sensitized nanoparticle system where a near-infrared-emitting quantum dot (QD) is used as a sensitizer with broadband photon absorption for a lanthanide-doped nanoparticle (LNP) to generate second near-infrared (NIR-II) emission. The NIR-II luminescence of Er