Single red upconversion luminescence in β-Ba2ScAlO5: Yb3+/Er3+ phosphor assisted by Ce3+ ions

Abstract

Recent decades have witnessed an explosion in research devoted to pure upconversion (UC) red emission attractive for bioimaging and anti-counterfeiting. Single-band red UC emission of Er3+ has been implemented in the new β-Ba2ScAlO5: Yb3+/Er3+ phosphor assisted by Ce3+. The red to green integrated intensity ratio reaches up to 430.9. Doping of Ce3+ ions leads to large cross-relaxation probabilities between Er3+ and Ce3+ ions when excited at 980 nm near infrared laser, resulting in suppressing the green emission and enhancing the red emitting level of Er3+. The optimal doping concentration of Ce3+ ions is 0.008 in β-Ba2ScAlO5: Yb3+/Er3+ sample, and a 4.1-fold red emission intensity enhancement was achieved than that of β-Ba2ScAlO5: Yb3+/Er3+ sample without Ce3+ ions. The possible upconversion luminescence (UCL) mechanism is investigated according to absorption spectrum, excitation spectrum, photoluminescence spectrum and upconversion emission lifetime decay spectrum of Yb3+/Er3+/Ce3+ co-doped β-Ba2ScAlO5, which was concluded that the 5d-4f energy transfer and large cross-relaxation probabilities between Er3+ and Ce3+ ions to achieve enhancement of red emission and the super-high ratio of red to green UCL emission integrated intensity. This work can pave a perspective way to obtain new phosphor with single UC red emission for applications in a variety of the fields.