Effects of Zn-doping on red-luminescence in Eu-doped (Mg,Ca)S phosphor films

For the improvement of emission efficiency, ZnS-doped Mg0.8Ca0.2S:Eu phosphor film was made using rf-magnetron sputtering method. When the concentration of ZnS in the film is 4%, the photoluminescence intensity is about three times higher than that of ZnS-non-doped Mg0.8Ca0.2S:Eu film with keeping pure red emission ( 650 nm). The crystal planes are oriented in (2 0 0) direction and make a solid solution with ZnS. Enhancement in photoluminescence (PL) intensity is closely related to the change of the crystal quality.