Controlled synthesis of NaYF4 nanoparticles and upconversion properties of NaYF4:Yb, Er (Tm)/FC transparent nanocomposite thin films

Monodisperse oleic acid stabilized pure NaYF4 nanoparticles with controlled size and shape have been successfully synthesized by changing the initial reaction temperature. Transparent nanocomposite thin films consisting of NaYF4:Yb, Er (Tm) upconverting nanoparticles (UCNPs) and fluorocarbon resin (FC) are deposited on the slide glass by dip-coating method. The results show that these nanocomposite thin films exhibit intense green and blue upconversion photoluminescence under 980 nm laser excitation and higher transparency than blank substrate. The NaYF4:Yb,Er (Tm) nanoparticles and NaYF4:Yb,Er (Tm)/FC nanocomposite thin films have been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), SEM/back-scattered electron (BSE), atomic force microscopy (AFM), UV–Vis spectrophotometer (UVPC), and photoluminescence (PL) spectra. These nanocomposite thin films can be potentially used in solar cells field.