ZnO deposited on Si (111) with Al2O3 buffer layer by atomic layer deposition

•ZnO thin films were grown on Si substrates by atomic layer deposition (ALD) with and without an Al2O3 buffer layer.•The growth temperature was 200 °C.•The insertion of Al2O3 buffer layer improved not only the crystalline quality but also the optical properties.

ZnO films were grown on Si (111) substrates by atomic layer deposition (ALD) at a low-temperature of 200 °C, and the structural and optical properties of the films were investigated. By inserting an ultrathin Al2O3 buffer layer between ZnO and Si, the crystalline quality of ZnO films was improved, resulting in the increase of the intensity of the photoluminescence.