Asian Research Thesis Index

Abstract

Li2O-BaO-Gd2O3-SiO2 and Li2O-BaO-GdF3-SiO2 glasses, doped with different rare earth ions (Dy3+ and Eu3+) have been synthesized by conventional melt quenching technique for the applications of solid state lightning devices (color LEDs), lasers and scintillation detectors. The developed glass samples have been investigated and characterized through their physical (density, molar volume, refractive index and optical energy gap, etc.,), structural (X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR)) and optical (absorption, excitation, emission and decay) properties. The various spectroscopic parameters such as, Judd-Oflet (JO) intensity parameters (Ωλ,λ = 2,4and 6), radiative lifetime (τR), transition probability (AR), branching ratio (βR), quantum efficiency (η), non-radiative relaxation rates (WNR), effective bandwidths (Δλeff), stimulated emission cross-section σ(λp) and CIE color coordinates for the present thesis have been calculated and analyzed by using various theoretical models anddifferent mathematical relations, which shows the same trend for all developed glass samples. The structural properties of the developed glasses have been investigated through XRD and FTIR spectra. The optical band and JO intensity parameters have been evaluated from optical absorption spectra. The optical and luminescence properties of the prepared glasses have been study with the help of absorption, transmittance, and photoluminescence and X- ray luminescence spectrum. Lifetime of all the developed glasses have been found to decrease with increase in concentration of rare earth ions. The energy transfer mechanism has been explained by using Inokuti–Hirayama (IH) model, which shows better fitting for S=6, which is dipoledipole interaction is dominant in the present glass samples. From the color coordinates values of LBGS-Dy glasses emits white light while LBGS-Eu and LBGFSEu emit red light. From the obtained results, LBGS-Dy, LBGS-Eu, and LBGFSEu glasses could be the potential hosts for the light emitting diodes and laser applications.

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