Synthesis and tuning orange to green up-conversion color in Y6WO12:Er/Yb phosphor

Abstract Spherical Yb 3+ , Er 3+ co-doped Y 6 WO 12 upconversion luminescence (UC) phosphors are prepared by the co-precipitation method. It is found that the phosphors presented uniform spheres at a wide range of annealing the precursors from 600 °C to 900 °C. With increasing the temperature, the particle size has no significant change, but the surface changed from smooth to rough. Further, under 980 nm near infrared (NIR) excitation, the upconversion intensity enhanced with increasing heating temperature, attributing to the more Er 3+ incorporated into the Y 6 WO 12 host. Notably, the luminescent colors of the samples could be modulated by changing the annealing temperatures. On the process of increasing heat-treatment temperature from 600 °C to 900 °C, the upconversion emission was tunable from orange to green, which provides a new channel to achieve materials emitting different colors. At last, the possible mechanisms involved were discussed.