Preparation of CaGa2S4:Ce thin films for blue emitting thin-film EL device

Blue emitting thin-film electroluminescent (TFEL) devices with Ce3+-doped calcium thiogallate (CaGa2S4:Ce) phosphor films have been prepared by multi-source deposition (MSD). Calcium (Ca), gallium(III) sulfide (Ga2S3) and cerium chloride (CeCl3) were employed as the source materials. The thin film deposited at a substrate temperature of 550°C with a View the MathML source flux ratio of 70 has a CaGa2S4 phase, but this film contained a gallium(II) sulfide (GaS) phase as well. The CaGa2S4:Ce thin films were successfully prepared by carrying out the annealing in H2S atmosphere. The film annealed at 800°C showed a bright blue photoluminescence (PL) with peaks at around 460 and 510 nm.