Oxygen Pressure Influence on Properties of Nanocrystalline LiNbO3 Films Grown by Laser Ablation

Abstract

Energy conversion devices draw much attention due to their effective usage of energy and resulting decrease in CO2 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 (LiNbO3, BaTiO3, etc.) are multi-component oxides, which significantly complicatestheirintegrationwithmicro-andnanoelectronictechnology. Thispaperreportstheeffect of the oxygen pressure on the properties of nanocrystalline lithium niobate (LiNbO3) films grown by pulsed laser deposition on SiO2/Si structures. We theoretically investigated the mechanisms of LiNbO3 dissociation at various oxygen pressures. The results of x-ray photoelectron spectroscopy study have shown that conditions for the formation of LiNbO3 films are created only at an oxygen pressureof1×10−2 Torr. Atlowresidualpressure(1×10−5 Torr),alackofoxygenintheformedfilms leadstotheformationofniobiumoxide(Nb2O5)clusters. Thepresentedtheoreticalandexperimental results provide an enhanced understanding of the nanocrystalline LiNbO3 films growth with target parameters using pulsed laser deposition for the implementation of piezoelectric and photoelectric energy converters.