Upconversion/downconversion luminescence of color-tunable Gd2O3:Er3+phosphors under ultraviolet to near-infrared excitation

Multicolored luminescence tuning in a single rare earth ion (Er3+) activated rare earth oxide phosphors were achieved among green to red colors. The emission bands in visible light region corresponding to the transitions between F-4(7/2) -> I-4(15/2) (487 nm), H-2(11)/2 -> I-4(15/2) (525 nm), S-4(3/2) -> I-4(15/2) (550 nm) and F-4(9/2) -> I-4(15/2) (667 nm) were demonstrated by luminescence spectroscopy under excitations at 379 nm and 980 nm. The dependence of upconversion/downconversion luminescence intensity on the firing temperature and Er3+ concentration were investigated, which is useful to tailor the color chromaticity coordinates under varied excitation wavelengths by adjusting the experimental conditions.