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

• A new optical glass, 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. • metaphosphate structure - boron oxide [BO 3 ] Q2 units - (P O B) bonds are identified. • SEM/EDS revealed that both dopants Dy 2 O 3 and Tb 2 O 3 are uniformly distributed. • PLE, TRPL and lifetime indicate energy transfer Dy3+ - Tb3+ at significant rate. 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 [BO 3 ] Q2 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. Normalized RT PL of the Dy/Tb co-doped glass sample, obtained with 301, 316, 353 and 384 nm wavelength excitation. The transitions involving states which J is integer correspond to Tb3+ and which J is half integer correspond to Dy3+. Image, graphical abstract [ABSTRACT FROM AUTHOR]