Structural, optical and NIR studies of Er3+ ions doped bismuth boro tellurite glasses for luminescence materials applications

Abstract

Abstract Bismuth Boro Tellurite (BiBT) glasses doped with Er3+ ions (i.e., Er3+ = 0.1, 0.5, 1.0, 1.5, 2.0, 2.5 mol %) were prepared by using melt quenching technique and their structural, optical absorption, emission and up-conversion properties were investigated using XRD, Raman, absorption, emission and decay spectral studies. The oscillator strengths measured from the absorption spectral features were subjected to Judd-Ofelt theory to understand the radiative properties possessed by the as prepared glasses. The titled glasses excited under 379 nm exhibited green luminescence at 547 nm (4S3/2 → 4I15/2). Upon pumping with a laser diode of 980 nm (NIR), a broad NIR emission at around 1572 nm (4I13/2 → 4I15/2) was observed for which stimulated emission cross-section (σse), effective band width (Δλp), gain band width (σse × Δλp) and optical gain (σse × τR) parameters were evaluated. The up-conversion luminescence shown by these glasses has been analysed to understand the utility of these glasses as up-conversion lasers. Among all the as prepared glasses, 1 mol% of Er3+ ions doped BiBT glass exhibits better radiative properties compared to other glasses. The gain cross-section of the 1 mol% of Er3+ ions doped BiBT glass was derived using absorption cross-section (σa) and emission cross-section (σe) for different values of population inversion (γ). The Decay spectral features recorded under 980 nm excitation were used to measure the experimental lifetimes (τexp) and quantum efficiencies. All the aforementioned studies revealed that the Er3+ ions doped BiBT glasses are quite suitable to fabricate optoelectronic devices in visible green and NIR regions.