Preparation And Characterization Of Transparent Conducting Mg_xZn_1-xO:Al Thin Films

In recent years, with the extensive application of short wavelength devices, the research of direct wide band gap semiconductor materials attracted more and more attention. ZnO is a kind of II -VI group semiconductor material, ZnO-based thin films have attracted much more attention as a wide band gap semiconductor material. ZnO-based thin films are extensively used in photoconductive devices and electronic devices, etc. They are regarded as the most potential materials to substitute ITO thin films.However, the difference between the band gap of ZnO thin films and that of ITO thin films is more than 0.4eV, the band gap of the former must be increased to substitute ITO thin films. If we are able to fabricate ZnO-based thin films with a band gap comparable to that of ITO thin films, morever, if the films have excellent electrical property, this will has great influence on the fabrication and application of transparent conducting films in the future. So our team began the research of Mg_xZn_1-xO:Al films.In this thesis, the preparation technology, property, application and researches on the electrical property and band gap project were introduced. Mg_xZn_1-xO:Al films were successfully fabricated on glass substrates by DC reactive magnetron sputtering and sol-gel methods, XRD, UV-Vis, Hall-effect measurements were employed to characterize properties of Mg_xZn_1-xO:Al thin films.The results showed that the Mg_xZn_1-xO:Al films were conductive and transparent in near ultraviolet range. The samples prepared by magnetron sputtering had a high preferred orientation with the c axis perpendicular to the substrate, the resistivity of Mg_xZn_1-xO:Al films increased with the Mg content increased, the band gap increased with the Mg doping concentration increased, while decreased with the substrate temperature increased. The samples fabricated by sol-gel didn't show c axis preferential oritention, the band gap also increased with Mg content increased, while the annealing temperature have on obviouce influence on the band gap of Mg_xZn_1-xO:Al films.