Electrostatically assembled fluorescent thin films of rare-earth-doped lanthanum phosphate nanoparticles

Abstract

We report on the formation of nanostructured, ultrathin films of a new class of fluorescent nanoparticles (NPs) within the same size range as quantum dots, but with a different kind of fluorescence, by using the layer-by-layer (LbL) technique. The fluorescence of these rare-earth-doped lanthanum phosphate (LaPO4) NPs is due to the bulk properties of the material and is therefore independent of their size. Additionally, different colors are available due to variation of the dopants used in their synthesis (e.g., Ce, Tb, Eu, and Dy). These NPs were electrostatically assembled to form thin films on planar quartz supports as well as on polystyrene (PS) microspheres with the aid of oppositely cha..