INFLUENCE OF PREPARATION CONDITIONS ON THE MICROSTRUCTURE AND OPTICAL PROPERTIES OF LiNbO3 THIN FILMS

Er3+/Yb3+: LiNbO3 thin films were deposited on sapphire (0001) substrates by spin coating. A deposition solution was prepared using a non-aqueous sol-gel method and 2-methoxyethanol, metallic lithium, niobium(V) ethoxide and erbium and ytterbium acetates. The compositions of two LiNbO3 solutions (1:1 or congruent) were tested to minimise the presence of (Er/Yb)NbO4 secondary phases. The effects of different temperatures (800 or 1000 C) and atmospheres (air or oxygen) during the crystallisation of the films was also investigated. Rapid annealing (1150 C with 55C/s heating rate) was also tested and its effects on secondary phase crystallinity and the luminescence of Er3+/Yb3+: LiNbO3 was established. The thin films were characterised using XRD, SEM and photoluminescence spectroscopy.