Oxygen Pressure Influence on Properties of Nanocrystalline LiNbO Films Grown by Laser Ablation.

Energy conversion devices draw much attention due to their effective usage of energy and resulting decrease in CO emissions, which slows down the global warming processes. Fabrication of energy conversion devices based on ferroelectric and piezoelectric lead-free films is complicated due to the difficulties associated with insufficient elaboration of growth methods. Most ferroelectric and piezoelectric materials (LiNbO, BaTiO, etc.) are multi-component oxides, which significantly complicates their integration with micro- and nanoelectronic technology. This paper reports the effect of the oxygen pressure on the properties of nanocrystalline lithium niobate (LiNbO) films grown by pulsed laser deposition on SiO/Si structures. We theoretically investigated the mechanisms of LiNbO dissociation at various oxygen pressures. The results of x-ray photoelectron spectroscopy study have shown that conditions for the formation of LiNbO films are created only at an oxygen pressure of 1 × 10 Torr. At low residual pressure (1 × 10 Torr), a lack of oxygen in the formed films leads to the formation of niobium oxide (NbO) clusters. The presented theoretical and experimental results provide an enhanced understanding of the nanocrystalline LiNbO films growth with target parameters using pulsed laser deposition for the implementation of piezoelectric and photoelectric energy converters.