LAUSR

Abstract Multicolor tunable upconversion luminescence materials could be applied to polychromatic LED and anti-counterfeit due to their superiority in abundant color and security feature. However, the harsh terms to achieve emission tuning associated with the drawbacks, including changing the concentration or types of doping ions, higher temperature, and higher excitation power, limit the range of its application. In this paper, a convenient and versatile approach for multicolor-emitting is realized via simply lower power modulating in TiO 2 :Yb 3+ / Er 3+ and TiO 2 : Yb 3+ /Er 3+ /Tm 3+ . The emission color is tuned from pink to yellowish green in TiO 2 :Yb 3+ / Er 3+ and tuned from white to yellowish green in TiO 2 : Yb 3+ /Er 3+ /Tm 3+ . It's found that there is no apparent temperature variation at lower power. Meanwhile, the mechanism of the emission and the multicolor tunability is discussed.