Strong light of red up-conversion in a ZnO-TiO2 composite containing Er3+ and Yb3+

The up-conversion (UC) phosphor produced by a metal-organic decomposition (MOD) method has a multifunctional potential for use in applications such as displays and solid-state lighting. ZnO-TiO₂ composite system containing Er³⁺ and Yb³⁺ were prepared by solid state reaction method, and the composite phosphor shows bright red UC emission under 980 nm laser pumping. Two photon process was involved in the UC phenomenon of the Er, Yb:ZnO-TiO₂ phosphor. The effects of heating temperature, ZnO/TiO₂ composition and Er³⁺, Yb³⁺ concentrations on the UC emission behavior were examined. The ZnO-TiO₂ composite product sintered at 900 °C contained Zn₂TiO₄, TiO₂ and RE₂Ti₂O₇ (RE = Er³⁺ and Yb³⁺) phases and exhibited strong red emissions. The maximum emission luminescence of the UC phosphor was obtained when the mixing ratios of the base materials TiO₂ : ZnO and additive materials Yb₂O₃ : Er₂O₃ were 1 : 1 and 0:06 : 0:02, respectively. The ZnO-TiO₂:Er³⁺, Yb³⁺ phosphor was compared to the brightest available phosphor. It suggests that ZnO-TiO₂:Er³⁺, Yb³⁺ is a potential material for the red up-conversion phosphor.