| Popis: |
Our research on the growing and characterizing of p-type ZnO thin films, prepared by radio frequency (RF) diode sputtering, mono-doped with nitrogen, and co-doped with aluminium and nitrogen, is a response of the need from p-type ZnO thin films for device applications. The dopants determine the conductivity type of the film and its physical properties. We obtained p-type ZnO thin films by RF diode sputtering and using a nitrogen dopant source. The novelty in our approach is in the use of a plasma assisted deposition method, to increase nitrogen solubility and the concentration of the NO acceptors in the film. The structural parameters, such as preferential orientation, crystallite size and strain in the film, depend on percentage of nitrogen in the working gas and the negative bias voltage. The XRD diffraction patterns reveal more or less stronger expressed c-axis preferential orientation of the films depending on the N2 content in the sputtering gas. The diffraction lines of ZnO (100), (002), (101), and (110) are observed in the XRD diffraction patterns of all ZnO:N thin film. Aluminium- nitrogen co-doping improves the crystalline structure and all ZnO:Al:N thin films show a c-axis texture in direction declined about 16 deg from the surface normal. Three diffraction lines ((100), (002) and (101)), appear only in the XRD patterns of the films deposited at 25 % N2, indicating that their preferential orientation is more random. A strong preferential orientation of the crystallites is observed for high dopant contents (50 % and 75 % N2) and intensities of the (002) diffraction lines are almost the same. |
