Spectroscopic studies of Pr3+ doped lithium lead alumino borate glasses for visible reddish orange luminescent device applications
2017; Elsevier BV; Volume: 708; Linguagem: Inglês
10.1016/j.jallcom.2017.03.020
ISSN1873-4669
AutoresNisha Deopa, A.S. Rao, Sk. Mahamuda, Mohini Gupta, M. Jayasimhadri, D. Haranath, G. Vijaya Prakash,
Tópico(s)Phase-change materials and chalcogenides
ResumoLithium Lead Alumino Borate (LiPbAlB) glasses doped with Pr3+ ions were prepared via melt quenching technique to study their luminescence behavior using absorption, excitation, photoluminescence (PL) and decay spectral studies. A broad hump observed in XRD confirms the amorphous nature of the as-prepared glass. The glass transition temperature (Tg) and thermal stability (ΔT) were measured from Differential Scanning Calorimetry (DSC). FT-IR and Raman studies were performed to understand the network functional groups involved in the host glass. Various radiative parameters for the prominent fluorescent levels of Pr3+ were evaluated with in the frame work of Judd-Ofelt theory. PL and confocal images recorded under 445 nm Continuous Wave (CW) diode laser excitation were used to understand the visible emission characteristic features of the as-prepared glasses. The decay profiles of 1D2 → 3H4 show single exponential for lower concentration and non-exponential for higher concentration resulting decrease in experimental lifetime (τexp) with increase in concentration. Such decrease in τexp and decay conversion from single to non-exponential with increase in rare earth ion concentration has been attributed to the cross-relaxation processes and subsequent concentration quenching observed. From the emission cross-sections, branching ratios, quantum efficiency, CIE coordinates and confocal images, it was concluded that 1 mol % Pr3+ ion concentration is optimum in LiPbAlB glasses to develop visible reddish orange luminescent devices.
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