Photoluminescence investigations on Dy3+ ions doped Zinc Lead Tungsten Tellurite glasses for optoelectronic devices

Dy3+ doped Zinc Lead Tungsten Tellurite (ZnPbWTe) glasses have been synthesized by conventional melt quench method and their luminescence behavior was analyzed using optical absorption, excitation, photoluminescence (PL) and PL decay spectral studies. The Judd-Ofelt (J-O) intensity parameters evaluated from the absorption spectra are used to determine various radiative parameters such as transition probability (A(R)), branching ratio (beta(R)) and radiative lifetimes (tau(R)) for the prominent emission transitions of Dy3+ ions in ZnPbWTe glasses. Under 384 nm excitation, PL spectra recorded for the titled glasses, exhibit two intense peaks; one in yellow at 575 nm and the other one in blue at 483 nm region. Among these two, yellow band (F-4(9/2) -> H-6(13/2)) is relatively more intense than the blue one (4(4)F(9/2) -> H-6(15/2)). The intensity of PL spectra increases up to 1 mol% of Dy3+ ions in ZnPbWTe glasses and beyond concentration quenching is observed. Branching ratios (beta(R)) and emission cross-sections (sigma(se)) were estimated for F-4(9/2) -> H-6(13/2) transition to understand the potential utility of these glasses for laser action in visible region. The CIE chromaticity coordinates, color correlated temperature (CCT), color purity and Y/B ratios were also estimated to understand the suitability of these glasses for w-LEDs. The luminescence quantum efficiency evaluated for the titled glasses showing highest value for 1 mol% of Dy3+ ions present in the as prepared glasses. From the measured emission cross-sections, quantum efficiency and CIE coordinates, it was observed that 1 mol% of Dy3+ ions in ZnPbWTe glasses are aptly suitable for optoelectronic devices such as lasers and w-LEDs.