Adjustable multicolor up-energy conversion in light-luminesce in Tb3+/Tm3+/Yb3+ co-doped oxyfluorifFde glass-ceramics containing Ba2LaF7 nanocrystals

Abstract

Abstract Transparent oxyfluoride glasses with highly efficient up-energy conversion (UEC) luminescence were developed in the 45SiO2-15Al2O3-12Na2CO3-21BaF2-7LaF3-xTbF3-yTmF3-zYbF3 composition (in mol%), and structural investigation by X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the formation of face-centered cubic Ba2LaF7 nanocrystals. The colors of UEC luminescences could be tuned easily by adjusting the concentration of doped rare earth ions and the excitation power of laser simultaneously. The relationship between the emission intensity of Tb3+/Tm3+/Yb3+ co-doped oxyfluoride glass-ceramics and the excitation pump power revealed that three-photon and two-photon absorptions predominated in the conversion process from the infrared into blue and red luminescences, respectively. A novel UEC mechanism of red emission from Tm3+ was proposed, energy transfers from Yb3+ to Tm3+ and Tb3+ and from Tm3+ to Tb3+ were evidenced. The possible mechanism responsible for the color variation of UEC in Tb3+/Tm3+/Yb3+ co-doped was discussed.