Preparation and up-conversion luminescence of NaY(WO4)2: Er3+/Yb3+ glass ceramics under different heat treatment conditions

NaY(WO4)2: Er3+/Yb3+ tungsten silicate glass ceramics were successfully synthesized by melting crystallization method. The crystal pattern, glass transition temperature, and chemical composition of glass ceramics samples were analyzed by XRD, DSC, Raman, and FTIR, respectively. The morphology and location distribution of grain was observed using scanning electron microscope (SEM). The energy transfer between rare earth ion was investigated by fluorescence spectra. Moreover, the crystal structure of glass ceramics and network structure of glass was also investigated, and the effect of grain precipitation on the structure of glass ceramics was analyzed. The influence of the amount of Er3+/Yb3+ on the luminescence intensity of the glass ceramics was investigated. Under the excitation of 980 nm laser, the glass ceramics samples showed strong green light emission. The strong green light emission at 527 nm and 550 nm consisted of the 2H11/2 → 4I15/2 and 2S3/2 → 4I15/2 energy level transition of Er3+, respectively. Both of two transitions are two photon processes. When the molar ratio of Er3+/Yb3+ is 1:9, the up-conversion luminescence intensity of the glass ceramics samples is the strongest.