An extreme high vacuum field emission microscope (XHV-FEM) was constructed for the study of inherent fluctuations of field emission (FE) current. The damping and fluctuation behaviors of FE from clean W(111) tips at 90 K were observed using the XHV-FEM. The noise of FE currents ranging from 10 pA to 100 μA was measured under ~7×10^-10 Pa. Stepwise features were routinely observed in damping curves of the FE current, indicating remarkable sensitivity of the FE current measuring system. The lowest frequency measurement of shot noise was recorded even at 4 Hz. Semilogarithmic damping curves of FE currents were linear in our thoroughly degassed XHV-FE system. The slope of semilogarithmic damping curves was linearly proportional to the operation pressure, suggesting a method of measuring pressure in an XHV range. An introduction to the XHV technology of Korea is also presented.

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  We have developed practical XHV chambers of a electron gun, of which the operating pressures are 1×10^-9 Pa in a stainless-steel one and 4×10^-9 Pa in a permalloy one. By mounting a noble single-atom electron source with high brightness and high spatial coherence on the electron gun including electron optics, we demonstrated highly collimated electron-beam emission: ~80% of the total emission current entered the electron optics. This ratio was two or three orders of magnitude higher than those of the conventional electron sources. In XHV, in addition, we confirmed stable electron emission up to 20 nA, which results in the specimen current high enough for scanning electron microscopes.

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  The new measurement method of outgassing speed with a sealed off quadrupole residual gas analyzer (RGA) has been proposed. The unique feature of this method is that the high vacuum can be maintained by the self-pumping effect of the ultra low outgassing RGA. The newly-developed mass analyzer combined with BA-gauge is the key for this method. The pressure of chamber can be maintained below 2~5×10^-7 Pa for a year without any pumping system. The majority of residual gases in the chamber were found to be hydrogen, methane and carbon-monoxide. In order to measure the outgassing speed of the RGA, the pumping speeds were measured by the self-pumping effect of RGA for hydrogen, deuterium, methane, nitrogen, carbon-monoxide, carbon-dioxide, oxygen and argon. When the pumping speed of RGA is balanced for outgassing from the RGA itself, we can calculate its value from the partial pressure in the spectrum. Then, we obtain the outgassing speeds for hydrogen=8.8×10^-13 Pa m³/s, methane=1.2×10^-13 Pa m³/s, carbon-monoxide=1.0×10^-13 Pa m³/s.

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  Low-cost fabrication of poly-Si TFT at low temperature is a key for the realization of flexible displays. By using pulsed-plasma CVD under near-atmospheric pressures, we have successfully obtained poly-Si films on polyethylene terephthalate substrates at a low temperature of 150°C. Judging from the dominance of the crystalline peak found in Raman scattering spectra as well as the absence of the incubation layer at the film/substrate interface observed in transmission electron micrographs, it is suggested that the quality of our poly-Si films is quite high. With its cost-effective and low-temperature-grown features, our high quality poly-Si produced in the pulsed-plasma CVD is expected to contribute greatly to the commercialization of flexible displays.

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  Recent progress in the development of dye-sensitized solar cell modules including so-called W-type, Z-type and S-type is reviewed with emphasis on our own activities. We have realized monolithically series-interconnected modules (so-called S-type) of 240 mm×240 mm in size, each consisting of 22 stripe-shaped cells with an automatable process employing improved screen-printed carbon-based counter electrodes (CE), and started outdoor performance test. We also developed 95 mm×95 mm transparent S-type modules with 12 stripe-shaped cells employing Pt-loaded In₂O₃-Sn nanoparticles in place of the carbon-based material for CE to compose plane-emitting night-lights driven by solar energy. Additionally, using specially designed S-type modules of 100 mm×106 mm to elucidate the intrinsic durability, we have obtained 2.5 years outdoor durability data telling 20% decrease from the initial conversion efficiency. These S-type modules are advantageous for cost reduction and suitable for mass-production as well as applications exploiting transparency and freedom in choice of colors. These modules are free from vacuum processing to attain a future competitive low production cost of electricity.

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  Microcrystalline silicon-germanium (μc-SiGe) films were fabricated on glass substrates by the RF reactive magnetron sputtering method using Ar and H₂ mixtures. We could reduce the crystallization temperature to 100°C and obtained the photosensitivity in the μc-SiGe films with any Ge content from 0 to 100%. These results indicate that the H₂ introduction into the sputtering gases has two important effects to decrease the crystallization temperature of the μc-SiGe films and to improve the film properties by the hydrogen termination of defects.

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  The definitions of some units of the International System are likely to be revised as early as 2011 by basing them on fixed values of fundamental constants of nature, provided experimental realizations are demonstrated with sufficiently small uncertainties. As regards the kilogram, experiments aiming at linking it to the Avogadro constant and the Planck constant are under way in several laboratories. Details are given on the experimental techniques developed to achieve the target. The other units likely to be redefined are the ampere, the kelvin and the mole. Advantages and disadvantages of different alternatives for revised definitions are discussed.

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  Erbium doped Ge-Ga-Se thin films were deposited by RF magnetron sputtering of powder and sintered composite targets. The dependence of the photoluminescence (PL) intensity of the films on the deposition conditions has been investigated. It is found that the intensity of PL depends on the RF power, whereas the composition of the films does not depend on that of the targets. Although the shape of PL spectrum in the films is similar to that of bulk glasses, the value of the PL life times in the films is shorter than that of bulk glasses. The reason would be the difference of composition of matrix glasses between bulk and the films.

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