Hydrothermal synthesis and green luminescent properties of Lu2O3:Yb3+/Ho3+ nanocubes.

Uniform and dispersive Lu2O3:Yb3+/Ho3+ nanocubes have been successfully synthesized by the hydrothermal process followed by a subsequent calcination at 800 degrees C. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL), cathodoluminescence (CL) spectra, as well as lifetimes measurements were utilized to characterize the synthesized phosphors. The as-formed RE(3+)-doped lutetium oxide precursor via the hydrothermal process as a template could transform to RE(3+)-doped Lu2O3 with their original cubic morphology and slight shrinkage in the size after the post-annealing process. The formation mechanism for the lutetium oxide precursor cubes has been proposed. Under the excitation of UV light, 980-nm laser and low-voltage electron-beams, Lu2O3:Yb3+/Ho3+ phosphors all show the characteristic emission of the Ho3+ ion (5F4, 5S2 --> 18 transition) withgreen color, which is easily observed by naked eyes. The corresponding luminescent mechanisms have been discussed. Due to the excellent PL (including up-conversion and down-conversion) properties and CL properties of the Lu2O3:Yb3+/Ho3+ phosphors, they are potentially applicable in fluorescent lamps, up-conversion fluorescent labels and FED devices as an efficient green phosphor.