Down/up conversion luminescence of erbium-ytterbium co-deposited nanoparticles on carbon nanotubes <i>via</i> a microwave-assisted method

In this study we present the synthesis of erbium, ytterbium and erbium-ytterbium nanoparticles supported on multiwalled carbon nanotubes by a microwave-assisted method as well as the evaluation of their luminescent properties. In the case of erbium, nanoparticles of ~1 nm homogeneously dispersed on the carbon nanotubes were obtained. In the case of ytterbium, the carbon nanotubes were partially coated with this metal. Clusters of erbium-ytterbium nanoparticles were obtained in the co-deposition of both metals. The erbium-ytterbium/carbon nanotube composite showed both down- and up-conversion luminescence. For the down-conversion process, strong emission signals at 523, 530 and 563 nm as well as a weak signal at 612 nm under 488 nm excitation are observed. For the up-conversion process, the composite showed emission signals centered at 528 and 660 nm under 980 nm excitation.