Cuprous oxide (Cu2O) thin films were grown epitaxially on c-axis-oriented polycrystalline zinc oxide (ZnO) thin films by low-pressure metal organic chemical vapor deposition (MOCVD) from Copper(II) hexafluoroacetylacetonate [Cu(C5HF6O2)(2)] at various substrate temperatures, between 250 and 400 degrees C, and pressures, between 0.6 and 2.1 Torr. Polycrystalline thin films of Cu2O grow as single phase with [110] axis aligned perpendicular to the ZnO surface and with in-plane rotational alignment due to (220)(Cu2O)parallel to(0002)(ZnO); [001](Cu2O)parallel to[1 (2) over bar 10](ZnO) epitaxy. The resulting interface is rectifying and may be suitable for oxide-based p-n junction solar cells or diodes. (C) 2009 Elsevier B.V. All rights reserved.