Solvothermal synthesis and upconversion properties in Yb3+/Ln3+ (Ln3+=Er3+/ Ho3+/ Tm3+) codoped In2O3 nanoparticles with fine stability

Monodisperse In 2 O 3 : Yb 3+ /Er 3+ upconverting nanoparticles (UCNPs) were firstly synthesized via solvothermal method in three-neck round-bottom flask. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR) methods are used to characterize the prepared UCNPs. The size of monodisperse spheroid nanoparticles prepared can be controllable in 31 nm. The sample exhibits stronger upconversion luminescence (UCL) than reported In 2 O 3 : Yb 3+ /Er 3+ UCNPs with similar size. Furthermore, the obtained In 2 O 3 UCNPs, by coating the SiO 2 protecting layer, display fine stability. Simultaneously, the UCL properties and possible energy transfer process of In 2 O 3 : Yb 3+ /Ho 3+ and In 2 O 3 : Yb 3+ /Tm 3+ NPs have also been investigated by the spectra distribution and power dependence. The results indicate Yb 3+ /Er 3+ , Yb 3+ /Ho 3+ and Yb 3+ /Tm 3+ codoped In 2 O 3 UCNPs is a probable oxide upconverting material with small size and intense UCL for biological applications.