Luminescence features of Ho3+ , Er3+ and Tm3+ ions in red lead added non-conventional antimony oxide glass system.

In this study, a glass system based on heavy metal oxides, namely Pb3 O4 -Sb2 O3 -SiO2 , was prepared with Ho2 O3 , Er2 O3 , and Tm2 O3 as dopants. The prepared glass were characterized using X-ray diffraction (XRD) and infrared (IR) studies. The luminescence efficiencies of the three rare earth ions viz., Ho3+ , Er3+ , and Tm3+ in the glass system were investigated, specifically focusing on green (Ho3+ , Er3+ ), blue (Tm3+ ), and near-infrared (NIR) emissions. The optical absorption (OA) and photoluminescence (PL) spectra of RE mixed glass displayed strong bands in the visible and NIR regions, which were analyzed using the Judd-Ofelt (J-O) theory. The J-O coefficients (Ωλ ) were found to be in the order of Ω2 > Ω4 > Ω6 for all the three glass. Notably, the Tm3+ -doped glass exhibited the lowest Ω2 value, which was attributed to a larger degree of disorder in the glass network due to lower fractions of Sb5+ and Pb4+ ions that take part in the glass network forming. This conclusion was arrived based on the IR studies. Furthermore, the quantitative analysis of PL spectra and decay curves indicated that SbHo and SbEr glass were suitable for efficient green emission, while SbTm glass is a promising choice for blue laser emission.

Amplification of blue emission of Tm3+ ions in Li2 O-HfO2 -SiO2 glass system by means of Au0 metallic particles.

Li2 O-HfO2 -SiO2 -Tm2 O3 :Au2 O3 glass samples (containing fixed content of Tm2 O3 and different concentration of Au2 O3 ) were prepared and characterized. Bearing of Au0 metallic particles (MPs) on improving blue emission of thulium ions (Tm3+ ) ions was explored. Optical absorption (OA) spectra exhibited multiple bands excited from 3 H6 of Tm3+ . Additionally, a broad peak in the wavelength range 500-600 nm due to surface plasmon resonance (SPR) of Au0 MPs was noticed in the spectra. Photoluminescence (PL) spectra (of thulium free glasses) indicated a peak in the visible range due to sp → d electronic transition of Au0 MPs. Luminescence spectra of Tm3+ and Au2 O3 co-doped glasses exhibited intense blue emission with substantial increase of intensity with increase of Au2 O3 content. Bearing of Au0 MPs on the reinforcement of blue emission of Tm3+ was discussed in detail with kinetic rate equations.

Concentration dependence of luminescence efficiency of Dy3+ ions in strontium zinc phosphate glasses mixed with Pb3 O4.

In this work we synthesized SrO-ZnO-P2 O5 glasses mixed with Pb3 O4 (heavy metal oxide) and doped with different amounts of Dy2 O3 (0.1 to 1.0 mol%). Subsequently their emission and decay characteristics were investigated as a function of Dy2 O3 concentration. The emission spectra exhibited three principal emission bands in the visible region corresponding to 4 F9/2  â†’ 6 H15/2 (482 nm), 6 H13/2 (574 nm) and 6 H11/2 (663 nm) transitions. With increase in the concentration of Dy2 O3 (upto 0.8 mol%) a considerable increase in the intensity of these bands was observed and, for further increase, quenching of photoluminescence (PL) output was observed. Using emission spectra, various radiative parameters were evaluated and all these parameters were found to increase with increase in Dy2 O3 concentration. The Y/B integral emission intensity ratio of Dy3+ ions evaluated from these spectra exhibited a decreasing trend with increase in the Dy2 O3 concentration up to 0.8 mol%. Quenching of luminescence observed in the case of the glasses doped with 1.0 mol% is attributed to clustering of Dy3+ ions. The quantitative analysis of these results together with infra-red (IR) spectral studies indicated that 0.8 mol% is the optimum concentration of Dy3+ ions needed to achieve maximum luminescence efficiency. Copyright © 2016 John Wiley & Sons, Ltd.