| Popis: |
Long afterglow phosphorescent SrAl 2 O 4 :Eu,Dy thin films have been fabricated on Si substrate by laser ablation. The thin film phosphors show the intense green emission near 520 nm, and additional emissions near 390 nm and near 450 nm that are originating from 5d–4f transition in Eu 2+ Eu 2 + ions doped in the thin films. The afterglow intensity at 520 nm of the thin film phosphors was detected over 20 min later, after excitation was removed. The afterglow characteristics is almost the same between in the SrAl 2 O 4 :Eu,Dy thin film phosphors and the SrAl 2 O 4 :Eu,Dy bulk phosphors. Then, the long afterglow characteristics are interpreted by the hole trapping due to the Dy 3+ Dy 3 + ions added as the auxiliary activator doped into the SrAl 2 O 4 thin films. |
Full Text from ScienceDirect