Graphene is a really single atom thick two-dimensional film consisting of only carbon atoms and exhibits very interesting material properties such as massless Dirac-fermions, Quantum Hall effect, very high electron mobility as high as 2×10⁶ cm²/Vsec. A. K. Geim and K. S. Novoselov had prepared this film by exfoliating from HOPG and put it onto SiO₂ substrate with the help of Scotch-Tape at year of 2004. And at the same time, they clearly showed the electric field effect by making a graphene device. Since then, graphene has been regarded as a post-silicon material all over the world and vast number of researchers had started to do research by paying attention on its physics and device operation. Here in this report, I shall briefly show the above mentioned trend in graphene reseach.

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  We have reviewed graphene and h-BN films grown on various metallic surfaces by using chemical vapor deposition techniques. In particular, a Ni(111) surface is an excellent substrate, on which the graphene grows in the epitaxial and commensurate way. Some properties on solid surface, such as electronic bands and phonon dispersion are shown. The chemical etching process to remove the Ni substrate makes it possible to prepare a self-supporting graphene film.

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  In this article, the method to fabricate a highly conductive graphene thin film from natural graphite powder through oxidation, exfoliation, deposition and reduction processes will be presented. Subsequently, the application of the graphene thin film to the electrodes of organic thin-film devices will be introduced.
  Chemically oxidized graphite powder was dispersed in water, and it was exfoliated by sonication or by repeated centrifugation and washing processes to obtain graphene oxide (GO). Successively a GO film was fabricated by coating a substrate with the GO solution, and it was chemically and thermally reduced to produce a highly conductive graphene film. Operation of organic thin film solar cells, which make use of the graphene films as their transparent electrodes, has been demonstrated. To date, the power-conversion ratio as high as 1% is achieved. Good operating performance of organic thin film field-effect transistors, which have graphene source/drain electrodes, is also demonstrated.

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  From its novel properties centered on the ultrahigh carrier mobility, graphene, an sp²-bonded carbon atom network, is now attracting skyrocketing attention. To pave a way to industrialization of this new material with inherent excellence, we have developed a method to form graphene on silicon substrates (GOS). By forming an ultrathin (∼100 nm) SiC film on Si substrate and by annealing the surface at 1200 C or higher in vacuo, few-layer graphene is formed on the Si substrate. This GOS technology is expected to bring about new horizon to the Si technology, which now faces several fundamental challenges for its further improvements.

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  Present understanding of electric transport in graphene, a crystalline layer of carbon, is reviewed. In the first part, emphasis is placed on the gap between the ideal and reality of electron transport, which is mostly caused by disorder (charged impurities) in the experimental samples. Disorder which affects the graphene transport originates mainly from charged impurities in the substrate, comtaminants on the graphene surface due to, e.g., resists and sticky tapes, and absorbed gas molecules. The amount of charged impurities and the methods to remove them are discussed. In the second part, the characteristic phenomena in multilayer graphene are explained for spins and Cooper-pair transport, which are relevant to the nonuniform distribution of the carrier density under nonzero gate voltages.

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  We review our recent experiments on the fabrication of nano-electronic devices in single-layer graphene. A graphene nanoribbon device was fabricated by conducting local anodic oxidation lithography using tapping-mode atomic force microcsope. The conductance of the graphene nanoribbon at the charge neutrality point was suppressed at low temperature, which suggests the opening of an energy gap due to the lateral confinement of charge carriers. A single quantum dot was fabricated by using the conventional electron beam lithography combined with plasma etching of the graphene layer. The quantum dot works as a single-electron transistor, which shows Coulomb blockade characteristics. These results suggest possibilities of the future application of the nano-electronic devices based on graphene.

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  We review our research toward single-crystal growth of epitaxial few-layer graphene (FLG) on SiC substrates, in which surface electron microscopy techniques have played essential roles. We have established a method for evaluating the number of graphene layers microscopically using low-energy electron microscopy. The number-of-layers dependence of the work function and C1s binding energy is determined using photoelectron emission microscopy. We use LEEM and thermionic electron emission microscopy to investigate the growth processes of epitaxial FLG. Uniform bilayer graphene a few micrometers in size is obtained by annealing in UHV.

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  Platinum palladium monoxide (Pt_1-xPd_xO) thin films with an arbitrary composition, where 0≤x≤1, were prepared by reactive cosputtering of platinum and palladium targets. The oxidation states of each atom of Pt and Pd were confirmed as that of PtO and PdO, respectively. Two infrared absorption peaks were found in the mid-infrared region and they exhibited linear peak shifts toward a lower wavenumber with increasing x. Thus, we completed successful preparation of Pt_1-xPd_xO thin films with a homogeneous phase. The crystallinity of the Pt_1-xPd_xO thin films improved when the composition exceeded x=0.56. The preferred orientation changed continuously between x=0 (PtO) and x=1 (PdO). The optical bandgap decreased when x decreased from 1, and became unclear in a low Pd content region, including x=0 (PtO).

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