This paper reports the preparation process and the long lasting phosphorescence of the Sr4Al14O25:Eu2+,Dy3+ thin films obtained by magnetron sputtering. Phosphorescence was achieved by annealing the films in reducing atmosphere. Sr4Al14O25 thin film was obtained when the films were treated at 1200 degreesC, while SrAl2O4 was generated as the intermediate phase during the annealing process. Sr4Al14O25:Eu2+, Dy3+ film generated an emission at 485 nm, and SrAl2O4:Eu2+, Dy3+ film showed an emission peaking at 515 urn. Afterglow characteristics were observed for both films, and Sr4Al14O25:Eu2+, Dy3+ film showed a better afterglow property than the SrAl2O4:Eu2+ ,Dy3+ film due to a deeper trap level and a higher trap concentration formed in the thin films. (C) 2004 Elsevier B.V. All rights reserved.