Luminescence of dysprosium doped strontium aluminate phosphors by codoping with manganese ion

Abstract

Abstract The authors report here the luminescence properties of strontium aluminate doped with dysprosium and manganese. The dysprosium, manganese co-doped powders were prepared by a solid state reaction at temperatures at 1600 °C under H 2 (15%)–Ar (85%) atmosphere. The dysprosium, manganese co-doped strontium aluminate phosphors have the monoclinic structure with lattice parameters a ≈ 8.440 A, b ≈ 8.821 A, c ≈ 5.157 A and β ≈ 93.4°. The characteristic 4 F 9/2 → 6 H 15/2 (blue), 4 F 9/2 → 6 H 13/2 (yellow), 4 F 9/2 → 6 H 11/2 (red) and 4 F 9/2 → 6 H 9/2 (NIR) transitions of Dy 3+ for different luminescence techniques (radioluminescence, photoluminescence and cathodoluminescence) were detected in the emission spectra at the room temperature. The luminescence of Mn 2+ co-doped SrAl 2 O 4 :Dy 3+ exhibits a broad green–orange emission band ( 4 T 1 → 6 A 1 transition) from the synthesized phosphor particles under different excitation sources. This corresponds to the spin-forbidden transition of the d-orbital electron associated with the Mn 2+ ion. Multiple emission lines observed at each of these techniques are due to the crystal field splitting of the ground state of the emitting ions. The nature of the emission lines is discussed.