X-ray photoelectron spectroscopy study of energy-band alignments of ZnO on buffer layer Lu2O3

Lu2O3 was used as the buffer layer of the epitaxy of ZnO film on Si substrate by plasma-assisted molecular beam epitaxy. X-ray photoelectron spectroscopy was used to determine the band alignment at ZnO/Lu2O3 interface. The conduction band offset (CBO) and valence band offset (VBO) of the ZnO/Lu2O3 heterojunction are calculated to be 1.77 eV and 0.66 eV, respectively, with a type-I band alignment. And the ratio of CBO and VBO (Delta E-c/Delta E-v) is estimated to be about 2.68. The large. Delta E-v and Delta E-c reveal that Lu2O3 is an ideal barrier layer in Si-based ZnO optoelectronic devices. (C) 2016 Elsevier B.V. All rights reserved.