title: Influence of Tl+ activator ions on the luminescence characteristics of KCl0.5Br0.5:Eu2+ powder phosphors.
abstract: Photoluminescence (PL) of thallium co-doped with KCl0.5Br0.5:Eu2+ powder phosphors display emission bands at 320 and 370 nm attributable to centres involving Tl+ ions in addition to characteristic Eu2+ emission around 420 nm. Additional PL excitation and emission bandS observed around 260 and 380 nm, respectively, were observed in the double-doped KCl0.5Br0.5:Eu2+, Tl+ powder phosphors and are attributed to complex centres involving Tl+ and Eu2+ ions. The enhancement observed in the intensity of Eu2+ emission around 420 nm with the addition of TlBr in KCl0.5Br0.5:Eu2+ powder phosphors is attributed to the energy transfer from Tl+ --> Eu2+ ions. Photostimulated luminescence (PSL) studies of gamma-irradiated KCl0.5Br0.5:Eu2+, Tl+ mixed phosphors are reported and a tentative PSL mechanism in the phosphors has been suggested.
authors.affiliation: Department of Physics, Pondicherry Engineering College, Puducherry-605014, India. nagarajansiva@yahoo.co.in
authors.forename: S
authors.initials: S
authors.lastname: Nagarajan
authors.forename: R
authors.initials: R
authors.lastname: Sudarkodi
mesh_terms: D005063:Europium / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D049449:Luminescence; D010758:Phosphorus / Q000737:chemistry*; D010777:Photochemistry; D013793:Thallium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D007477:Ions; D010758:Phosphorus; D005063:Europium; D013793:Thallium