Luminescence and photometric activity of an intense green emitting ZnBiBaBFTe:Tb3+ glasses

Borotellurite (ZnBiBaBFTe: ZnO + Bi2O3 + BaF2 + B2O3 + TeO2) glasses were fabricated by varying Tb2O3 concentration via the conventional melt and rapid quenching process. The glass stability (150 °C) and thermal stress (0.336) were evaluated using the differential thermal analysis. The rising value in the molar volume (39.69–43.86 cm3/mol) and field strengths (6.69–19.41 × 1015 cm−2) was due to the decrease in the density (2.932–2.804 gm/cm3) and inter-atomic distances (5.25 - 3.08 Å) of Tb3+ ions in ZnBiBaBFTe glasses. Measured excitation (PLE) and de-excitation (PL) spectra indicated that Tb3+:ZnBiBaBFTe glasses can be efficiently stimulated from 377 nm of UV radiation and exhibit a dazzle of green emission (543 nm) belonging to the transition 5D4→7F5 of Tb3+ ion. The radiative parameters of the level 5D4 of Tb3+ ion was predicted from the Ω2, 4, 6 intensity parameters by means of the JO (Judd-Ofelt) phenomenological formalism. Rise in Tb3+ concentration led to the enhancement of 5D4 emission transitions and reduction of lifetimes (2.24–1.82 ms) via dipole-dipole interaction. The detailed analysis of glasses revealed efficient lasing action parameters corresponds to branching ratio (> 60%), emission cross-section (14.61 × 10−22 cm2), gain bandwidth (15.34 × 10−28 cm3), and quantum efficiency (79%) along with photometric parameters like (x, y) color coordinates (∼0.29, 0.60), color purity (65%), and correlated color temperatures (∼6000 K) for green lasing applications.