Photoluminescence and thermoluminescence properties of manganese doped BaAl2O4 phosphor

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Vol. 278; p. 115604
• Main Authors: Manaka, M.C., Mothudi, B.M., Dhlamini, M.S.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.04.2022; Elsevier BV
• Subjects: Chemical composition; Crystal structure; Decay curves; Glow curves; Manganese ions; Morphology; Nanophosphor; Nanophosphors; Nanorods; Phosphorescence; Phosphors; Photoluminescence; Rare earth elements; Spinel; Thermoluminescence; Decay curves; Nanophosphor; Phosphorescence; Spinel; Thermoluminescence
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2022.115604

[Display omitted] •Bright green emission from Mn2+ with potential use in displays technologies.•Linear correlation in the range of 120–420 Gy dose, proved potential for dosimetry.•XPS: photoemission peak of Mn4+, suggesting that Mn2+ oxidized to Mn4+.•Average decay measurements of 4.88 ms, with average activation energy of 0.84 eV. A novel rare-earth free green-emitting Mn doped BaAl2O4 nanophosphor was prepared by combustion method. The crystal structure, morphology, phosphorescence, thermoluminescence and chemical composition were investigated. The XRD patterns confirmed the hexagonal BaAl2O4 phase and the existence of a small fraction of BaAl12O19 impurity phase. The SEM studies revealed uneven morphology with both nano-rods and hexagonal sheets particles. PL measurements, excited at 428 nm, exhibited a 512 nm emission from the 4T1→6A1(6S) transition of Mn2+ ions and a very weak emission band at 685 nm from the 2Eg→4A2g transition of Mn4+ ions. The green emission at 512 nm was observed to have an average decay time of 4.88 ms. Thermoluminescence measurements showed a glow curve with at least one prominent peak around 114 °C, and two weak peaks at 186 °C and 292 °C. The kinetic analysis proved it to be of second order, with an average activation energy of 0.84 eV.