Facile on-demand oriented growth of perovskite oxide thin films: applications of Dion–Jacobson phase as seed layer

Abstract

We investigated a new fabrication process for high-quality, uniaxial-oriented grown Dion–Jacobson perovskite (DJP) RbLaNb2O7 thin films by means of excimer laser assisted metal organic deposition. Oriented crystal growth occurred only by excimer laser irradiation in air at 400 °C after a deposition of metal–organic solution and preheating at 400 °C. The obtained RbLaNb2O7 thin film showed perfect (010)-oriented growth on borosilicate glass substrates, and the film surface had atomically flat terraces. We confirmed that the obtained DJP RbLaNb2O7 thin films functioned very well as a seed layer for the fabrication of various perovskite oxide thin films with high orientation quality. An oriented grown LaNiO3 thin film fabricated on the DJP seed layer and prepared at 400 °C exhibited low electrical resistivity at room temperature. Moreover, we demonstrated the utility of our methodology for on-demand fabrication by combining our method with an inkjet printing technique to pattern LaNiO3 thin films with a line shape, which also were successfully grown with uniaxial orientation on the DJP seed layer. A ferroelectric Na0.5K0.5NbO3 perovskite film was heteroepitaxially grown on the uniaxial-oriented grains of the LaNiO3/RbLaNb2O7 thin film, and this oriented film exhibited a higher dielectric constant than that of a film fabricated without the DJP seed layer. Thus, we demonstrated facile, oriented crystal growth enabled by the uniaxial-oriented DJP seed layer.