Optical and electrical properties of Co-doped epitaxial ZnO films

Abstract Epitaxial ZnO films doped with Co were fabricated by the high throughput combinatorial laser molecular-beam epitaxy method. The solubility limit of Co in ZnO was determined. Transmission and cathodoluminescence spectra were measured to study the electronic structures of Co in Zn 1− x Co x O films. Magnetoresistance behavior was measured for a selected sample co-doped with 1 mol% of Al to investigate s–d exchange interaction between the conducting s electron spins and the d electron spins localized at Co impurity. Huge magneto-optical effects comparable with that of Cd 1− x Mn x Te were observed on Zn 1− x Co x O films.