Structure, Judd-Ofelt analysis and spectra studies of Sm3+-doped MO-ZnO-B2O3-P2O5 (M = Mg, Ca, Sr, Ba) glasses for reddish-orange light application

In the present work, a series of Sm3+-doped MO-ZnO-B2O3-P2O5 (M = Mg, Ca, Sr, Ba) glasses were prepared. The glass structure and luminescence properties were investigated by XRD, DSC, IR, absorption spectroscopy, Judd-Ofelt theory and photoluminescence spectra. The J-O parameters of Sm3+-doped glasses follow the trend of omega 4>omega 6>omega 2. Under the excitation of 401 nm Xenon lamp, Sm3+-doped glasses exhibited four emissions from the transitions of 4G5/2 -> 6HJ/2 (J = 5, 7, 9, 11) in the visible spectra. The luminous intensity of Sm3+ increases with the asymmetry in local environments and decreases with the increasing radius of the alkaline-earth cation. Among the as-prepared glass, the Sm3+-doped glass containing magnesium oxide exhibits higher values of stimulated emission cross-section (2.18 x 10-21 cm2), gain bandwidth (1.40 x 10-27 cm3), and optical gain (3.83 x 10-24 cm2). All the Sm3+-doped glasses show intense orange light in the CIE 1931 chromaticity diagram with a high color purity exceeding 99%. In addition, the time-resolved emission spectra reveal the decay process of the Sm3+ ions for the transitions 4G5/2 -> 6H7/2 and 4G5/2 -> 6H9/2 in the glass containing magnesium oxide. It suggests that Sm3+-doped alkaline-earth zinc borophosphate glasses could be a potential candidate for reddish-orange light-conversion fluorescent materials based on the ultraviolet light-emitting diode.