E. Martínez, F. Ramos, M. García, O. Alvarez-Fregoso and S. López,

Instituto de Investigaciones en Materiales, UNAM, A.P. 70-3016, Coyoacan 04510, Mexico, D.F., Mexico.

Europium doped Al₂O₃ photoluminescent films have been prepared by ultrasonic spray pyrolysis process, using a solution of 0.005M of AlCl₃-6H₂O as starting material and EuCl₃ as doping. The substrate temperature and the doping concentration were varied. A disordered growth was observed for the substrate temperatures used (300-540°C). The excitation and emission espectra have been obtained. For an excitation wavelength of 395nm all the photoluminescent spectra show bands located at 587 nm, 600 nm, 612 nm and 648 nm, characteristic of the trivalent europium ion. A quenching of the fotoluminescence is observed at values of activator concentration above 10 atomic porcent (a/o) in the solution.