Abstract
The emission peak is shifted to shorter wavelength region with substitution of II family element in II-III_2VI_4 compounds such as CaGa_2S_4:Ce. However there are few reports in which III family element was controled for II-III_2-VI_4 compounds. In this report, CaAl_2S_4:Ce thin film EL devices were fablicated by two targets pulse electron-beam evaporation. Although the EL devices showed pure bluish-purple emission with a peak at around 420nm, the luminance level of CaAl_2S_4:Ce EL device was lower than that of CaGa_2S_4:Ce EL device. Therefore CaGa_2S_4:Ce-CaAl_2S_4:Ce stacked-layer and Ca(Ga, Al)_2S_4:Ce solid solution EL devices were prepared by this method. From these devices, it is successful that high luminance and blue-emission purity was obtained.
