John M. Schloss, from Yankton, SD, an undergraduate student in the Department of Chemistry at the University of South Dakota, is working on the fabrication and characterization of layer-by-layer thin films containing lanthanide (Ln)-doped upconversion nanoparticles in Dr. Chaoyang Jiang’s research group. Upconversion nanoparticles, Ln-doped NaYF4 with diameters below one-hundred nanometers, can be incorporated into polyelectrolyte multilayer thin films by using spin-assisted layer-by-layer assembly. By using atomic force microscope, John and his labmate revealed the aggregation of NaYF4 nanoparticles on the polymer surface. Furthermore, the same area was studied with confocal fluorescence microscope and the optical properties of the individual cluster of NaYF4 nanoparticles were investigated. John’s work will help advance the knowledge of the surface modification and assembly of upconversion nanomaterials.

The research is enabled by the summer internship award from the SD EPSCoR and the state of South Dakota.

Transmission electron micrograph of Lanthanide-doped NaYF4 nanoparticles.

 

Picture of solar cells after layers of materials were
evaporated onto the ITO substrates consecutively.