Professor and Head, Materials Design Center, Research Institute, Kochi University of Technology, Japan.

Speech Title: Correlation between carrier transport and orientation evolution of polycrystalline highly transparent conductive oxide films
Abstract: We demonstrate a nanoscale materials design to achieve high-Hall-mobility oxide polycrystalline films such as ZnO and In₂O₃ films deposited on amorphous glass substrates at a low temperature for use as the transparent electrodes of flat panel displays and in the window layers of solar cells, as chemical sensors and so on. Very recently, for Al-doped ZnO textured polycrystalline films deposited by direct-current magnetron sputtering on 10-nm-thick Ga-doped ZnO films with a well-defined (0001) orientation, with no intentional post-heat annealing, we reported a high Hall mobility of 50.1 cm² /Vs with a carrier concentration of 2.55 × 1020cm⁻³ . The key factor is to enhance intragrain carrier mobility together with a substantial reduction of the contribution of grain boundary scattering to carrier transport due to a high degree of c-axis alignment between columnar grains. The development of the technique with a nanoscale materials design of very thin films is expected to help us understand the mechanisms of carrier transport of highly doped ZnO polycrystalline films.