Facile Synthesis and Luminescence Properties of Y_2O_3:Ln~(3+) (Ln~(3+) = Eu~(3+), Tb~(3+), Dy~(3+), Sm~(3+), Er~(3+), Ho~(3+), Tm~(3+), Yb~(3+)/Er~(3+), Yb~(3+)/Tm~(3+), Yb~(3+)/Ho~(3+)) Microspheres

摘要

Multicolor and monodisperse Y_2O_3:Ln~(3+) (Ln~(3+) = Eu~(3+), Tb~(3+), Dy~(3+), Sm~(3+), Er~(3+), Ho~(3+), Tm~(3+), Yb~(3+)/Er~(3+), Yb~(3+)/Ho~(3+)) microspheres were prepared through a facile urea-assisted homogeneous precipitation method followed by a subsequent calcination process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectrum (EDS), Fourier transformed infrared (FT-IR), thermogravimetric analysis (TGA), photoluminescence (PL) and cathodoluminescence (CL) spectra were employed to characterize the samples. The XRD results reveal that the as-prepared spheres can be well indexed to cubic Y_2O_3 phase with high purity. The SEM and TEM images show the obtained Y_2O_3:Ln~(3+) samples consist of regular nanospheres with the mean diameter of 350 nm. And the possible formation mechanism is also proposed. Upon ultraviolet and low-voltage electron beams excitation, Y_2O_3:Ln~(3+) (Ln~(3+) = Eu~(3+), Tb~(3+), Dy~(3+), Sm~(3+), Er~(3+), Ho~(3+), Tm~(3+)) samples exhibit respective bright red (Eu~(3+), ~5D_0 → ~7F_2), green (Tb~(3+), ~5D_4 → ~7F_5), blue (Dy~(3+), ~4F_(9/2) → ~6H_(13/2)), yellow (Sm~(3+), ~4G_(5/2) → ~6H_(7/2)), green (Er~(3+), ~4S_(3/2) → ~4I_(15/2)), green (Ho~(3+), ~5S_2 → ~5I_8), blue (Tm~(3+), ~1D_2 → ~3F_4) down-conversion (DC) emissions. Under 980 nm NIR irradiation, Y_2O_3:Ln~(3+) (Ln~(3+) = Yb~(3+)/Er~(3+), Yb~(3+)/Tm~(3+) and Yb~(3+)/Ho~(3+)) exhibit characteristic up-conversion (UC) emissions of green (Er~(3+), ~2H_(11/2), ~4S_(3/2), ~2H_(11/2) → ~4I_(15/2)), blue (Tm~(3+), ~1G_4 → ~3H_6) and green (Ho~(3+), ~5F_4, ~5S_2 → ~5I_8), respectively. These merits of multicolor emissions in the visible region endow this kind of material with potential applications in the field of light display systems, lasers, and optoelectronic devices.