Synthesis of white light LaF3: 20%Yb3+, 0.1%Ho3+, 1%Tm3+ single nanocrystals by precipitated transformation method

In this article, we describe the production of uniform hexagonal phase LaF3:20%Yb3+, 0.1%Ho3+, 1%Tm3+ (LFYHT) monodisperse nanoparticles through a hydrothermal precipitated transformation reaction using La(OH)3: 20%Yb3+, 0.1%Ho3+, 1%Tm3+ (LOYHT) nanorods as parent materials. The trivalent rare earth hydroxides were hydrothermally prepared at 180 °C. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) analysis showed the LFYHT nanoparticles to have an average size of 10 nm and diameters similar to those of LOYHT nanorods. The upconversion spectra of the sample were measured using a fluorescence spectrophotomere with single-wavelength diode lasers (980 nm) at room temperature. Red, green, and blue emissions were associated with the synthesized sample. The calculated color coordinates demonstrated that white light can be produced in a wide range of pumping powers.