X ray photoelectron spectroscopy study of energy band alignments of ZnO on buffer layer Lu2O3
Abstract 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 D E c D E v is estimated to be about 2.68. The large D E v and D E c reveal that Lu2O3 is an ideal barrier layer in Si based ZnO optoelectronic devices.