ZnO thin films that function as either transparent conducting oxides in solid-state photovoltaic cells or as nanocrystalline dye-absorbers in dye-sensitized solar cells have the potential to reduce the cost of producing electricity from solar energy. Although there exist many methods to produce ZnO thin films, the most economical and practical method may be oxidation of metallic Zn thin films. This research examined the utility of ex-situ thermal oxidation of DC magnetron sputtered Zn thin films in generating useful ZnO thin films for these photovoltaic applications. We annealed Zn thin films in air at 570° C in order to produce ZnO thin films. We monitored the film’s resistance and ZnO:Zn composition ratio using relative peak intensities from X-ray diffraction spectra as a function of anneal time. We found that DC magnetron sputtered Zn films that are converted to ZnO by thermal oxidation in air are several orders of magnitude too resistant to be used as transparent conducting oxides in solid-state photovoltaic cells, but that this method of production may provide ZnO films that can be used as a dye absorbing semiconductors in dye-sensitized solar cells.
"ZnO Thin Films Generated by Ex-Situ Thermal Oxidation of Metallic Zn for Photovoltaic Applications,"
Macalester Journal of Physics and Astronomy:
1, Article 12.
Available at: http://digitalcommons.macalester.edu/mjpa/vol4/iss1/12