Realizing nearly pure green and red emissions of Ho³⁺/Yb³⁺ co-doped Gd₂(MoO₄)₃ through tri-doping Eu³⁺ and Ce³⁺

The nearly pure green and red emissions of Ho³⁺/Yb³⁺ co-doped Gd₂(MoO₄)₃ were realized by tri-doping Eu³⁺ and Ce³⁺, respectively. The Ho³⁺/Yb³⁺ co-doped Gd₂(MoO₄)₃ powder, radiating intense green and red emissions, was prepared by a typical sol-gel method. Under the excitation of 980 nm laser, the red-to-green ratio was tuned from 0.2 to 4 as the concentration of Eu³⁺ changed from 6 to 0 mol%, attributed to the energy transfer processes between Ho³⁺ and Eu³⁺. Meanwhile, the red-to-green ratio altered from 4 to 20 as the concentration of Ce³⁺ changed from 0 to 20 mol% via the cross relaxing processes between Ho³⁺ and Ce³⁺. The prepared phosphors, possessing large tuning range of red-to-green ratio and resisting high temperature, can be potentially applied to colorful display and solid-state lighting.