Structural and luminescence characterization of lithium-borosulfophosphate glasses containing dysprosium ions

Rare earth doped glasses have been a great deal of research interest due to their prominent applications in laser lighting technology. However, achieving highly efficient yellow light emission from these materials require the collective efforts of many researchers across the world. Hence, a series of high optical quality dysprosium doped lithium-borosulfophosphate glasses with chemical composition of 15Li2O-30B2O3-15SO3-(40-x)P2O5-xDy2O3 (where x = 0.1, 0.3, 0.5, 0.7 and 1.0 in mol%) were prepared by convectional melt quenching technique and characterized by X-Ray diffraction (XRD), Fourier Transform Infrared (FTIR) and Photoluminescence (PL) measurements. XRD pattern of the host glass confirms its amorphous nature while the results from FTIR spectra analysis indicates the presence of BO3, BO4, PO4 and SO42- groups in the host network structure. The photoluminescence spectral analysis revealed three emission bands at 494 nm, 585 nm and 673 nm attributed to the electronic transitions of 4F9/2→6H15/2, 4F9/2→6H13/2 and 4F9/2→6H15/2,respectively, under the excitation of 386 nm. Among all the prepared glass samples, 1.0 mol% Dy3+ contained glass sample exhibits an intense yellow emission at 585 nm which specifies its prospective suitability for yellow laser applications.Keywords: Borosulfophosphate glasses, Dysprosium ions, Fourier transform infrared spectroscopy, Photoluminescence analysi

Influence of Eu3+ dopant on physical and optical properties of lithium-borosulfophosphate glasses

Multi-components glass host with enhanced physical and optical features are greatly demanding for various photonics and optoelectronics devices. Selection of suitable glass former, modifier, and dopant ions with optimized composition is a key concern in the fabrication of novel optical glass materials for the aforementioned purpose. Thus, this work reports the convectional melt quench synthesis of europium (Eu3+) doped lithiumborosufophosphate glasses with composition 15Li2O-30B2O3-15SO3-(40-)P2O5-Eu2O3 (where = 0.1, 0.3, 0.5, 0.7 and 1.0 in mol%). The effect of P2O5 substitution by Eu2O3 on their physical (density, molar volume, ion concentration, polaron radius, inter-nuclear distance and field strength) and optical properties was examined. The amorphous nature of the samples was confirmed by XRD diffraction pattern. The density of glass samples was slightly increased with increasing concentration of Eu2O3. Such trend is attributed to the higher molecular weight of Eu2O3 (351.926 g/mol) than P2O5 (141.9445 g/mol). The room temperature absorption spectra revealed four weak bands in the UV-Vis range and two strong bands in the NIR range with 1.0 mol% glass sample possessing the highest intensity at 7F0→7F6 (2095 nm). Incorporation of Eu3+ ion significantly enhanced the glass absorbance and the physical properties. The results on high refractive index (~2.3), polarizability and non-linear physical features suggest that these glasses are potential for photonics and solid-state laser applications.Keywords: Borosulfophosphate glasses, Europium ions, physical properties, optical properties and photoluminescenc

Optoelectronic properties of XIn2S4 (X = Cd, Mg) thiospinels through highly accurate all-electron FP-LAPW method coupled with modified approximations

We report the structural, electronic and optical properties of the thiospinels XIn2S4 (X = Cd, Mg), using highly accurate all-electron full potential linearized augmented plane wave plus local orbital method. In order to calculate the exchange and correlation energies, the method is coupled with modified techniques such as GGA+U and mBJ-GGA, which yield improved results as compared to the previous studies. GGA+SOC approximation is also used for the first time on these compounds to examine the spin orbit coupling effect on the band structure. From the analysis of the structural parameters, robust character is predicted for both materials. Energy band structures profiles are fairly the same for GGA, GGA+SOC, GGA+U and mBJ-GGA, confirming the indirect and direct band gap nature of CdIn2S4 and MgIn2S4 materials, respectively. We report the trend of band gap results as: (mBJ-GGA) > (GGA+U) > (GGA) > (GGA+SOC). Localized regions appearing in the valence bands for CdIn2S4 tend to split up nearly by approximate to 1 eV in the case of GGA+SOC. Many new physical parameters are reported that can be important for the fabrication of optoelectronic devices. Optical spectra namely, dielectric function (DF), refractive index n(omega), extinction coefficient k(omega), reflectivity R(omega), optical conductivity sigma(omega), absorption coefficient alpha(omega) and electron loss function are discussed. Optical's absorption edge is noted to be 1.401 and 1.782 for CdIn2S4 and MgIn2S4, respectively. The prominent peaks in the electron energy spectrum situated between 15 eV and 23 eV for the herein studied materials indicate a transition from metallic to the dielectric character.close0