ELECTRONIC CHARACTERIZATION OF ZNO CUO HETEROJUNCTIONS/

CuO/ZnO heterocontacts have previously been reported to exhibit nonlin ear I-V characteristics which are sensitive to their environment inclu ding reducing gases and humidity. A detailed understanding of these ph enomena are, however, not yet available, especially in terms of the el ectronic structure of the heterojunction. In this study, more reproduc ible methods for preparing p-CuO/n-ZnO heterojunction devices are atte mpted following thin-film techniques. The properties of CuO/ZnO hetero junctions prepared by reactive sputter deposition are being investigat ed taking into account oxygen stoichiometry, film thickness and morpho logy. D.c. and a.c. impedance measurements performed as a function of temperature and atmosphere are used to examine modifications in the ju nction's barrier characteristics. A model for the electronic structure of the CuO/ZnO heterojunction and its reported sensitivity to its env ironment is being developed on this basis.