Structural and luminescence characterization of a Dy/Tb co-doped borophosphate glass

A new optical glass with the molar composition 20B(2)O(3)-50P(2)O(5)-10Li(2)O-9Al(2)O(3)-5ZnO-3Dy(2)O(3)-3Tb(2)O(3) was obtained by melting-quenching technique comprising wet route raw materials preparation, and the structural and optical characteristics of the glass were investigated by different experimental techniques. The amorphous nature was confirmed by X-ray diffraction (XRD) and the thermal stability was assessed by differential thermal analysis (DTA). Information about the defects of the co-doped glass as well as about the elemental compositional homogeneity was revealed by scanning electron microscopy/energy dispersive spectrometry (SEM/EDS). Structural information provided by Fourier Transform Infrared (FTIR) and Raman spectroscopy indicated metaphosphate structure of the glass together with boron oxide mostly in [BO3] Q(2) units and also P-O-B bonds. Ultraviolet-visible (UV-Vis) absorbance, photoluminescence (PL), photoluminescence excitation (PLE) and time resolved photoluminescence (TRPL) spectra and luminescence decay curve were investigated systematically. Energy transfer process between Dy3+ and Tb3+ ions and its influence on luminescent properties were discussed.