The structure and optical characters of the ZnO film grown on GaAs/Al2O3 substrate

Abstract In this paper ZnO films are grown on GaAs/Al 2 O 3 substrates at different temperature by metal-organic chemical vapor deposition (MOCVD). The GaAs/Al 2 O 3 substrates are formed by depositing GaAs layer (∼35 nm) on the Al 2 O 3 substrate. The results of X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) demonstrate that most of the Ga and As atoms form Ga–As bond and the GaAs layer does not present any orientation. The characters of the ZnO films grown on GaAs/Al 2 O 3 substrates are investigated by XRD, photoluminescence (PL), atomic force microscopy (AFM) and Raman scattering. Compared with ZnO film grown on Al 2 O 3 substrate, ZnO film prepared by our fabrication scheme has good crystal and optical quality. Meanwhile its grain size becomes bigger according to the AFM image. Raman analysis indicates that the intrinsic defects and the in-plane tensile stress are obviously reduced in ZnO/GaAs/Al 2 O 3 samples.