Investigations on optical and photoluminescence properties of Dy3+ doped zinc tellurite glass

Abstract

• The structural, thermal and optical properties of the Dy 3+ doped tellurite (TZND) glass system were investigated. • Properties of samples were measured and described in the current study using XRD, SEM, and EDS methods. • The forbidden energy gap values for the direct and indirect transitions are found between 2.98 and 3.02 eV and 2.90–2.94 eV respectively. • The effects of Dy 3+ ion on absorption and photoluminescence spectra were studied. • The TZND glasses doped with Dy 3+ ion have potential to be the best photonic and light emitting host material. Zinc-sodium-tellurite glasses doped with Dy 3+ (TZND) with the chemical compositions (70-x) %TeO 2 –20 %ZnO–10 %Na 2 O-x%Dy 2 O 3 (where × is 0, 0.5 and 1 in mol%) were synthesize by traditional melt-quenching method. The samples were characterized using X-ray diffraction, SEM-EDS, optical absorption and PL spectra. Differential scanning calorimetry (DSC) was carried to determine the glass transition temperature of synthesized samples. The non-crystalline nature of TZND samples was confirmed by XRD measurements and compositions were verified by EDS. Raman spectra have been carried to characterize the architectural attributes of glass matrices. Other parameters of prepared samples as density(ρ), molar volume (V m ), polaron radius R p , oxygen packing density and intermolecular distance R i were calculated. The optical band gap, refractive index (n), cut-off wavelength, and the Urbach's energy were determined from the absorption spectra. The PL spectra for upconversion characteristics indicate two intense bands due to 4 F 9/2 → 6 H 15/2 (around 480 nm) and 4 F 9/2 → 6 H 13/2 (around 570 nm) transitions respectively.