Upconversion enhancement in dye sensitized core/shell structure nanoparticles

Multicolor lanthanide upconversion nanophosphors (UCNP) that converted near-infrared radiation into emission at the short wavelength show excellent photophysical properties, but low conversion efficiency and fluorescence quenching of surface modification still limits its further application. Here, we report a dye-sensitized composite nanomaterials with enhanced upconversion under 980 nm excitation. We systematically studied the influence of different conditions on upconversion luminescence, including competitive luminescence center, dye molecules, dye concentration and different composite systems . The results indicated the upconversion fluorescence can be enhanced 20 times when coated with phosphatidylcholine (PC). The compound structure wrapped with PC gives full play to the advantages of promoted upconversion, showing a good biomedical application prospect and providing more opportunities for biomedical and energy application.