Growth of Er3+-doped LiNbO3 thin-film on LiTaO3 by e-beam evaporation

Growth of Er 3+ -doped 100-nm thick LiNbO 3 (LN) films on Z-cut LiTaO 3 (LT) single-crystal by e -beam evaporation and in-situ anneal at 600–800°C was studied. Crystalline phase, crystallographic orientation, Er 3+ spectroscopic properties, constituent element valence states, defects, Er 3+ concentration and stoichiometry of the films were characterized. The results show that the films are in LN single-crystal state and orient along with c crystallographic axis. Constituent elements Li, O and Er are present in their respective single valence states Li + , O 2− , Er 3+ , while the Nb is in two valence states Nb 5+ and Nb 4+ . The films have Li 2 O-contents around congruent point. Antisite(Nb Li 4+ ) is the major defect. Its concentration decreases, while Li 2 O-content, crystallinity degree, and fluorescence intensity increase with increased growth temperature. The presence of Er 3+ in the grown films is in the form of LN crystalline phase. Its concentration is considerably lower than that in initial target material because of lower e -beam evaporation efficiency of heavy Er 3+ .