Structural, thermal and broadband NIR emission properties of Nd3+/Pr3+/Ag NPs co-doped tellurite glass

Nd3+/Pr3+ co-doped tellurite glasses containing metallic Ag NPs were synthesized by melt-quenching and heat-treating techniques. The amorphous structural nature, fundamental vibrational units and good thermal stability of the prepared tellurite glasses were confirmed by X-ray diffraction (XRD) pattern, Raman spectrum and differential scanning calorimeter (DSC) curve, respectively. The precipitated Ag NPs in a glass matrix with an average diameter similar to 5 nth were revealed by transmission electron microscopy (TE\1) image, and the radiative property of Nd3+: and Pr3+ ions was evaluated from the absorption spectrum by Judd-()felt theory. Under the excitation of 488 nth Xenon lamp, two broadband near-infrared emissions covering 800 100 nm and 1250-1650 nm ranges were observed from the fluorescence spectrum. The former originated from the transitions of Pr3+:P-3(1,0) -> (1)G(4), Pr3+: D-1(2) -> F-3(4,3), Nd3+: F-4(3/2) -> I-4(11/2) and Nd3+:F-4(3/2)-> I-4(9/2), while the latter was contributed by the Pr3+: (1)G(4) -> H-3(5) Pr3+: D-1(2) -> (1)G(4), Pr3+ :F-3(3) -> H-3(4) and Nd3+ :F-4(3/2) -> I-4(3/2) transitions. With the introduction of Ag NP,s, the emission intensity of two broadband near-infrared emissions was further enhanced, in which the peak emission intensity of 1250-1650 nm band was increased by about 56% and the FWHM is up to 250 nm. The obtained results indicate that Nd3+/Pr3+/Ag NPs co-doped tellurite glass has great potential in realizing ultra-broadband near infrared emission covering O-, E- and S-bands simultaneously. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement