Annealing effects of morphology and luminescence properties of pulsed laser-deposited SrAl2O4: Eu, Dy thin films on sapphire (0001) surfaces

The current work reports on the effect of annealing temperatures on the morphology and photoluminescence properties of SrAl2O4: Eu, Dy thin films on sapphire (0001) substrates fabricated by pulsed laser deposition technique. Scanning electronic microscopy and atomic force microscopy were used to investigate the thickness, surface topography, and the morphology of the films. The film deposited using a higher annealing temperature was packed with a uniform layer of larger particle size grains. In addition, the surface of this film was shown to be relatively rougher than that without annealing treatment. An intense green emission, which is attributed to the 5d-4f transition of Eu2 + was observed at about 520 nm from the films with annealing treatment. The effects of annealing treatment on the morphology, topography, and photoluminescence properties are discussed in detail.