Epitaxial Growth of Cu2O on Ag Substrate by Electrodeposition

Abstract

In this study, the epitaxial growth of Cu2O on Ag substrate by electrodeposition was studied by a combinatorial substrate approach mainly using the electron backscatter diffraction technique. Cu2O films were deposited galvanostatically in an electrolyte containing copper sulfate and lactic acid at four current densities. Results indicated that the substrate grains exhibited similar surface roughness values of approximately 3-5 nm regardless the orientation. At a low current density of 0.060 mA/cm2, the deposited film has a rough surface composing of faceted islands of about 1 mm in size. No orientation relationship (OR) between the crystals and substrate grains can be identified. About 50% of the Cu2O crystals deposited at 0.125 mA/cm2 exhibits a cube-on-cube OR with their underlying grains, whereas those grew on a <100>//ND grain exhibiting a <100>/45° OR. With increasing the deposition current density to 0.250 mA/cm2, many substrate grains were deposited by a flat epitaxial layer having a <100>/45° OR. Only few <100>//ND grains are covered by a cube-on-cube epilayer.