FLUORESCENT MATERIAL THIN FILM AND MANUFACTURING METHOD THEREFOR

PROBLEM TO BE SOLVED : To provide a fluorescent material thin film formed by doping a rare earth element ion as a light-emitting center into an Al2O3 thin film as a mother crystal, that is excellent in controlling the composition and the concentration of the light-emitting center, and has a good color purity and a high brightness. SOLUTION : This fluorescent material thin film comprises an Al2O3 thin film as a mother crystal laminated on a heated substrate, and a CeO2 thin film as a rare earth element oxide for a light-emitting center laminated thereon. It has a structure in which the light-emitting center is present as a component of a solid solution in the mother crystal of the Al2O3 thin film. The Al2O3 and CeO2 thin films are formed by sputtering. The fluorescent material thin film prepared in an atmosphere of a gas mixture of argon and hydrogen emits a very strong blue light.