The blue luminescence of cerium doped aluminum oxide thin film

Abstract

Amorphous aluminum oxide thin films doped with cerium have been deposited by middle frequency reactive magnetron sputtering. There exist Ce3+ ions in the Al2O3:Ce thin films as shown by XPS measurement. The photoluminescence emission from these films show peaks around 374 nm which are associated with 5d to 4f transitions of Ce3+ ions. The intensity of these peaks is strongly dependent on the amount of cerium incorporated in the films. The presence of cerium as well as the stoichiometry of these films have been determined by energy dispersive X-ray spectroscopy (EDS) measurements. It is proposed that the light emission observed is generated by luminescence centers associated with trivalent ionic cerium impurities. The crystalline structure of the sample was analysed by X-ray diffraction (XRD). Auger electron spectroscopy has been used to estimate the stoichiometry of the films. This luminescence feature is advantageous for display techniques which require a purer blue emission.