Investigation on structural and luminescence features of Dy3+ ions doped alkaline-earth boro tellurite glasses for optoelectronic devices

A Series of Alkaline-Earth Boro Tellurite (AEBT) glasses doped with different concentrations of Dy3+ ions have been prepared by using melt quenching technique and characterized using spectroscopic techniques such as XRD, Raman, optical absorption, excitation, photoluminescence (PL) and PL decay to understand their utility in optoelectronic devices such as lasers and white light emitting diodes (wLEDs). The XRD spectrum revealed non-crystalline nature whereas the Raman spectrum revealed the phonon energy and various functional groups present in the undoped host glass. The intensities of the electronic transitions and the ligand field environment around the Dy3+ ions were studied by applying Judd-Ofelt (J-O) theory to the recorded absorption spectra of the AEBTDy glasses. The J-O parameters were used to measure various radiative parameters for the prominent fluorescent levels of Dy3+ ions in the asprepared glasses. The emission spectra of Dy3+ ions doped AEBT glasses under 387 nm excitation show three emission transitions F-4(9/2) -> H-6(15/2) (blue), F-4(9/2) -> H-6(13/2) (yellow), and F-4(9/2) -> H-6(11/2) (red) of which the yellow transition observed at 575 nm is highly intense. The fluorescence decay curves for the as prepared glasses have been recorded for 757 nm transition under 387 nm excitation wavelength. The experimental lifetimes (tau(exp)) measured from the decay spectral profiles are combined with radiative lifetimes (tau(R)) to measure quantum efficiencies of the asprepared glasses. The yellow to blue intensity ratios and chromaticity color co-ordinates are found to vary with Dy3+ ion concentrations. All the aforementioned results finally revealed that the AEBT glasses doped with Dy3+ ions are aptly suitable for the design and development of optoelectronic devices such as wLEDs and lasers.