By using the molecular beam epitaxy (MBE) and plasma assisted MBE with oxygen atmosphere

the ZnO thin films were deposited on Si(100)

GaAs(100) and Al

2

O

3

(0001) substrates with Zn

ZnS

or Zn-O buffers respectively

under different temperatures of beam source and of substrate. The buffer layer is necessary for preparation of ZnO thin film

in order to minimize the effect of mismatch of crystal lattice between substrates and ZnO. In the X-ray diffraction spectrum

we can observe peaks specific to ZnO at (100)

(002)

(101)

(102)

and (103). There are some shifts of diffraction peaks for ZnO thin film at different substrates. The atomic force microscope images (AFM) show that the ZnO films are composed of small granules with nano size. The thickness of film was found about several nanometers

by using the grazing incidance X ray reflectivity method. Under the excitation of 360 nm

the photoluminescence of ZnO films is a broad spectrum with peaks at 410 and 510nm. We suggest that the luminescence is due to deep levels related to the oxygen defects at the surface.