Fabrication of Tb–Mg codoped CaSnO3 perovskite thin films and electroluminescence devices

Thin films of CaSnO3:Tb–Mg perovskite phosphor were prepared on silica glass substrates or SrTiO3 (100) single crystal substrates by RF sputtering method. Intense green photoluminescence originating from Tb ions was observed from the films under uv (λex = 254 nm) excitation. Furthermore, electroluminescence devices using the CaSnO3:Tb–Mg phosphor were fabricated and their luminescence properties were examined. The device fabricated on the SrTiO3 substrate showed electroluminescence above an applied ac voltage of 500 V and green electroluminescence was clearly observed from the CaSnO3:Tb–Mg phosphor layer. Essence of the electroluminescence in the present devices was discussed along with an estimation of the electric field strength in the phosphor layer.