Facile patterning of upconversion NaYF4:Yb,Er nanoparticles

Abstract

Different kinds of highly ordered patterns of NaYF4:Yb,Er nanoparticles on gold substrates were fabricated using a simple method combining micro-contact printing and " breath figures" techniques. Ordered arrays of water droplets were first formed in the hydrophilic regions of patterned self-assembled monolayers (SAMs). This was subsequently submerged in a chloroform solution of NaYF4:Yb,Er nanoparticles. The particles were spontaneously assembled at the interface of chloroform/water droplet surface, leading to different kinds of uniform patterns after solvent evaporation. The structures of NaYF4:Yb,Er particles patterns depended on the dimension of the substrate, the concentration of the NaYF4:Yb,Er nanoparticles and the water condensation process. © 2010 Elsevier Inc.