Exploiting valence band mapping and select blue-green and red phosphorescence decay of γ-irradiated nanoscale Eu3+: Gd2O3 below concentration quenching

Abstract We report on manifested blue-green and red emission features in Eu3+ doped Gd2O3 nanophosphors, subjected to 1.3 MeV gamma (γ) -irradiation and up to a dose of 2.4 kGy. While Eu 3+ states can be predicted at the core, occurrence of divalent species (Eu2+) at the nanoparticle surfaces was revealed from the X-ray photoelectron spectroscopy (XPS) studies. Characteristic Eu3+ activated orange-red emissions (590–650 nm) were revealed, and the nature of the corresponding transitions assigned. Moreover, time resolved photoluminescence (TR-PL) technique was employed to evaluate the lifetime of carriers participating in specific recombination emission events with and without specimens being exposed to γ -rays. The lifetime decay of our nanophosphor ranges between ∼1.6–1.3 ms, for electrically driven (ED: 5D0→7F2) and ∼1.98–1.56 ms, for magnetically driven (MD: 5D0→7F1) emissions. The modulation of ED and MD transitions in a suitable nanophosphor will have immense scope in next generation smart windows, display panels and bioimaging prospects.