Structural and electrical properties of Cu2O thin films deposited on ZnO by metal organic chemical vapor deposition

Abstract

Cu 2 O thin films were deposited on ZnO coated glass substrates by metal organic chemical vapor deposition from copper(II) hexafluoroacetylacetonate [Cu(C5HF6O2)2], oxygen gas, and water vapor. The dependence of the structural and electrical properties of Cu2O films on deposition temperature and film thickness was investigated. X-ray diffraction showed that Cu2O thin films grow on ZnO with preferred (220)Cu2O∥(0002)ZnO orientation. The grain size and stress in Cu2O films increase with increasing substrate temperature but decrease with increasing film thickness. The carrier mobility increases with increasing grain size indicating that the carrier transport is limited by scattering from the grain boundaries. Single-phase epitaxial p-type Cu2O films with hole mobilities exceeding 30 cm2/V s are obtained at a deposition temperature of 400 °C.