Characterisation of sputtered thin films of SrGa2O4:2% Ce, 2% Li

Thin films of Ce- and Li-doped alkaline earth gallates have been deposited on barium titanate substrates by RF-magnetron sputtering and post-annealed in pure argon or in a slightly reducing atmosphere of hydrogen/argon mixtures. These alkaline-earth gallates, in their bulk form, emit bright blue light when excited by photoluminescence or cathodoluminescence sources. However, the deposited films were inactive under the same excitation sources. Ion beam analysis determined that the difference between the bulk and thin films was a depletion of Li in the films.