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 Pb3O4-Sb2O3-SiO2, was prepared with Ho2O3, Er2O3, and Tm2O3 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 (Omega(lambda)) were found to be in the order of Omega(2) > Omega(4) > Omega(6) for all the three glass. Notably, the Tm3+-doped glass exhibited the lowest Omega(2) 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.