Solvothermal synthesis and upconversion luminescence of ultra-small Sc2O3: Yb, Er nanoparticles

Monodisperse sub-10 nm Sc2O3: Yb, Er upconverting nanoparticles (UCNPs) were firstly synthesized via solvothermal method in three-neck round-bottom flask. The X-ray diffraction (XRD) shows that the prepared UCNPs possess cubic structure. The transmission electron microscopy (TEM) shows that sample has monodisperse spheroid morphology with high crystallinity. The average size of spheroid UCNPs could be controllable manipulated as small as 3 nm. Furthermore, the sample exhibits stronger red and green upconversion luminescence (UCL) than reported Sc2O3: Yb, Er nanostructure by biphasic solvothermal method. The Fourier-transform infrared (FTIR) spectra and decay curve reveal that ultra-small Sc2O3: Yb, Er UCNPs exhibit the reduced surface groups and long decay time of Er3+ ions. The results indicate Sc2O3: Yb, Er UCNPs is a probable oxide material with small size and intense UCL for biological applications.