Epitaxial potassium niobate thin films prepared by metalorganic chemical vapor deposition

Abstract

Epitaxial potassium niobate thin films were deposited in situ by low pressure metalorganic chemical vapor deposition (MOCVD) at a growth temperature of 800 °C using niobium pentaethoxide and potassium tert-butoxide as volatile metalorganic precursors. Growth on single crystal (100) lanthanum aluminate substrates produced [110]-oriented potassium niobate films. The films have a smooth, featureless morphology. Atomic force microscopy of the MOCVD-derived films surface indicates a root-mean-square roughness of less than 2 nm. Second-harmonic generation of 1.064 μm incident light is observed from the potassium niobate thin films, and the effective second order nonlinear susceptibility d of the as-deposited film is as high as 13 pm/V.