Structural Properties Of Zno Thin Film Research

AbstractZnO, which has a wurtzite crystal structure, is a wide bandgap(Eg=3.37ev), low dielectric constant and high chemical stability semiconductor. Because of its electrical, optical, and piezoelectric properties, Epitaxial ZnO thin film has many potential applications, especially in the optoelectronic fields. This paper engaged in the research work of the influences of different growth conditions on features of ZnO thin films in several aspects, especially in the impacts of different substrates and growth temperatures, respectively. In this paper, a reactive electron beam(e-beam) evaporation system was used for the low temperature epitaxy of high-quality ZnO thin films on Si(OOl) and glass substrates. The optimal growth temperatures were between 200癈 and 300癈 for Si(OOl) substrates and 300癈 and 350癈 for glass substrates, respectively. Structural characteristics grown on both Si and glass were studied by measurements of X-ray diffraction(XRD), and Raman scattering. X-ray diffraction showed the ZnO thin films grown on both Si(OOl) and glass substrates were all highly c-axis-oriented and their line width of (002) diffraction peak is 0.28? However, Raman scattering demonstrated the presence of excess zinc in the ZnO/glass structure. The microstructures of ZnO thin films have been investigated by atomic force microscope(AFM). The results showed that the crystal structure and the orientation and the surface morphology of ZnO thin films were affected significantly by growth temperature. ZnO thin films grown on both Si(OOl) substrates at a substrate temperature of 255 癈 and glass substrates at a substrate temperature of 325 癈 have a good crystal structure and a flat and smooth surface with an average roughness of <2nm(on Si(OOl) substrates) and <3nm(on glass substrates), respectively. All in all, the studies of ZnO thin films in the paper make effort in the optoelectronic fields of the development and applications.