Luminescence properties of ZnO films grown on GaAs substrates by molecular-beam epitaxy excited by electron-cyclotron resonance oxygen plasma

Growth of ZnO films on GaAs(0 0 1) substrates is demonstrated using ZnS buffer layers by metalorganic molecular-beam epitaxy excited by electron-cyclotron resonance oxygen plasma. Bright near band-edge luminescence was observed at room temperature and the deep-level emission was found to make little contribution to the optical spectrum. The Stokes shift of the luminescence measured at 15 K with the photoluminescence excitation spectrum was almost absent. These distinguished features are the clear manifestations of the quite high optical quality of the ZnO films grown on GaAs substrates. (C) 2000 Elsevier Science B.V. All rights reserved.