Photoluminescence (PL) and electroluminescence (EL) from newly developed Eu-activated CaAl2O4 -based multicomponent oxide phosphor thin films prepared by rf magnetron sputtering are described. Yellowish green and blue emissions in PL were obtained in as-deposited and postannealed ((CaAl2O4)(1-x)-(BaAl2O4)(x)):Eu and ((CaAl2O4)(1-x)-(MgAl2O4)(x)):Eu thin films, respectively. In addition, blue emission in EL was observed from thin-film electroluminescent (TFEL) devices fabricated by using ((CaAl2O4)(1-x),-(BaAl2O4)(x)):Eu thin films postannealed at 1000 degrees C in an Ar+H-2(5%) gas atmosphere. A luminance of 3.2 cd/m(2) for blue emission was obtained in a ((CaAl2O4)(0.44)-(BaAl2O4)(0.56)):Eu TFEL device driven by a 1 kHz sinusoidal wave ac voltage; the blue EL emission corresponds to the CIE color coordinates of (x = 0.24, y = 0.13). (C) 2008 American Vacuum Society.