Ceramics-Silikáty 59 (2) 164-168 (2015)

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

Thin films of Er³⁺/Yb³⁺: LiNbO₃ were deposited on sapphire (0001) substrates using a spin-coating process. A deposited solution was prepared by a non-aqueous sol-gel method using 2-methoxyethanol, metallic lithium, niobium(V) ethoxide and erbium and ytterbium acetates. Two starting compositions of LiNbO₃ solution (1:1 or congruent) were tested in order to minimize the present of secondary (Er/Yb)NbO₄ phases. The effect of different temperature (800°C or 1000°C) and different used atmosphere (air or oxygen) during the films crystallization was also investigated. Rapid annealing (at 1150°C with the heating rate 55°C·s^-1) was also tested and its influence on secondary phases crystallinity and luminescence of Er³⁺/Yb³⁺: LiNbO₃ was established. The thin films were characterized by X-ray diffraction analysis, scanning electron microscopy and photoluminescence spectroscopy.

Keywords: Lithium niobate, Thin film, Sol-gel, Rapid annealing