Spectroscopy and absolute photoluminescence quantum yield of Eu3-doped zinc-tellurite glasses for solid state lightning applications

Abstract

Spectroscopic properties of Eu3+-doped tellurite glass composed of 74 TeO2 + 15 ZnO +5 Nb2O5 + 5 TiO2 + 1.0 Eu2O3(mol %) have been investigated. Phonon energy of the host glass constituents that are linked up with the Eu3+ ions have been evaluated from the photoluminescence excitation spectrum which is found to be 760 cm−1. By utilizing the emission spectrum, the Judd-Ofelt (JO) intensity parameters (Ωλ, λ = 2 and 4) are calculated. The obtained JO parameters are utilized for evaluating the emission cross-sections (σ(λp)) of 5D0 → 7FJ (J = 1, 2 and 4) transitions. An intense emission at 613 nm due to the transition5D0 → 7F2is observed upon 465 nm excitation. Among these, the 5D0 → 7F2 (613 nm) transition has been exhibited the highest (σ(λp)) value and it found to be 2.11 × 10−22 cm2. For the 5D0 level, quantum efficiency (η) is corroborated theoretically as 58.4% and it is in line with absolute quantum yield of 56.7% obtained by Integrating sphere method. The results of Eu3+-doped TZNTEu1.0 glass are significant for the development of solid-state lighting devices at around 613 nm under the excitation of 465 nm.