Kiyoshi Yoshikawa (Director, Institute of Advanced Energy) Introduction of the Institute of Advanced Energy in Kyoto University The Institute of Advanced Energy, Kyoto University has celebrated its eighth anniversary this year prior to the structural reform of the national universities into independent agencies in 2004. Yet, the mission of the institute--generation, conversion, and utilization of environment-conscious, advanced, high-quality energy--will become even more relevant in this century. Activities will be introduced, considering rapid growth of world population and globalization of economical activities.
Masahiro Shioji (Graduate School of Energy Science) Introduction to the Graduate School of Energy Science The Graduate School of Energy Science was founded in April 1996, with the aim of providing continuous leadership in global energy science. It has four departments; Socio-Environmental Energy Science, Fundamental Energy Science, Energy Conversion Science and Energy Science and Technology, which cover a spectrum of advanced and interdisciplinary research fields. The Graduate School has carried out the education and research on energy and environmental problems. It has devoted itself to create new field of energy science that consists of combinations of cultural science, social science, and natural science and technology. The Graduate School has also nurtured a lot of energy specialists and communicated with society.
Yukio H. Ogata (Institute of Advanced Energy) Porous Silicon Research at CRCP We have carried out research on porous silicon for nearly ten years at the CRCP (Chemical Reaction Complex Processes Research Section). The activities are classified in three categories, characterization of the surface, the porous layer formation, and metal deposition onto the surface. They are briefly outlined, and then the surface modification with metal especially by means of immersion plating and possibilities of the application to solar energy utilization are presented.
Patrik Schmuki (Chair for Surface Science and Corrosion, Dept. Mat. Sci. Univ. Erlangen, Germany) Porous Silicon Research at LKO In recent years, the localized dissolution of semiconductors has generated a great deal of interest as a result of the discovery of light emitting porous silicon and its large number of potential applications. For other semiconductor materials such as the III-V compounds - despite their numerous applications in optoelectronic devices and a wide range of investigations regarding their anodic passivation behaviour - electrochemical work related to pore formation is rarely found in the literature. The talk addresses recent and current own activities within this field. For GaAs and InP a variety of internal and external factors were found to influence the pore formation process, as well as the optical properties of the porous structures. Parameters that significantly affect pore growth and morphology will be discussed as well as means to achieve lateral as well as vertical high resolution (nanoscopic) patterning of porous structures.
Keisuke Makino (International Innovation Center and Institute of Advanced Energy) DNA damage by a physiologically essential signal molecule, nitric oxide Nitric oxide is known to be an essential physiological molecule, however in some case such as inflammation, it is also known to be overproduced, which may cause pathological events. In the present study, our results obtained for the overall reaction mechanism of nitric oxide with DNA moieties and its implication will be shown. Particularly nature of the resulting modified residues, such as oxanosine and diazoate intermediates will be described in detail.
Joachim Kaschta (Chair for Polymer Materials, Dept. Mat. Sci. Univ. Erlangen, Germany) Advanced Polymer Materials The talk will give a general survey over the main research fields of the Institute of Polymer materials. Two projects will be discussed in more detail:
Tetsuo Yamazaki (Institute of Advanced Energy) Advanced Photon Energy and its Applications We consider “photon energy” as one of fundamentals to be studied and specially promoted at the IAE. The research and development are in progress for the generation and control of superior photon energy and its applications. We are developing a free-electron laser system and high-intensity ultrashort-pulse lasers as photon energy sources and basic tools for energy researches. Researches on application of such laser are being carried out from various aspects, e.g. surface processing and generation of polarized electrons. In the 21COE program, solar energy (including solar cells) is one of the key areas of research.
Richard Auer (ZAE, Erlangen, Germany) Thermosensorics and Photovoltaics
Kiyoshi Yoshikawa (Institute of Advanced Energy) Inertial Electrostatic Confinement Plasma Neutron/Proton Sources Inertial-Electrostatic Confinement of a fusion plasma, first proposed in 1950's aiming at the future fusion power plant, is basically a beam-beam colliding fusion device with an extremely compact and simple configuration. The research is now spreading out aiming at advanced innovative technologies, such as positron emitter production for cancer diagnostics, landmine detection through nuclear reaction, and so on.
Thierry Djenizian (Chair for Surface Science and Corrosion, Dept. Mat. Sci. Univ. Erlangen, Germany) Electron beam induced nanomasking of semiconductors
Tetsuo Sakka (Institute of Advanced Energy) Laser Ablation at solid-liquid interfaces We have been studying pulsed laser ablation in CRCP (Chemical Reaction Complex Processes) research section in IAE. Especially, we focus our attention on the irradiation of a solid target submerged in liquids. This configuration confines the ablation species into a small region due to the presence of a liquid, and is expected to give high pressure, high temperature and high density region. A spectroscopic analysis and characterization of the ablation region will be presented in the symposium.
Florian Pyczak (Chair for General Materials Properties) Metallic materials for High-Tech-applications: microstructures ranging from nano-grained to single crystal Present day metals and alloys are not only used for everyday applications but certain metallic materials are specially tailored for the purposes of high-tech applications. For example nickel-base superalloys exhibit high strength at high temperatures while nano-grained pure titanium shows improved mechanical properties for medical applications comparable with titanium alloys which contain additional elements like vanadium which could cause problems in respect to bio-compatibility. The key to such outstanding mechanical properties are specially designed microstructures like materials, consisting of one principal grain for improved high temperature creep toughness or materials with grain sizes below 500 nm which exhibit extremely high room temperature toughness. Based on these two examples, it will be shown how the actual microstructure influences the mechanical properties and how changes in the material's behaviour can be traced back to changes in microstructure.
Masahiro Shioji (Graduate School of Energy Science) Combustion Engineering in Power Systems Laboratory of Energy Conversion Systems aims to optimum design and control of the thermal energy conversion systems with high efficiency, safety and ability for environment protection. Special attention is currently paid to develop the combustion engineering in power systems at the following research subjects; 1) Analysis of combustion processes in internal combustion engines, (2) Fundamental studies on ignition and combustion of fuel sprays and fuel jets, (3) Effective utilization of alternative fuels for combustion systems, (4) Laser diagnosis and image analysis for combustion research.
Horst P. Strunk (Chair for Microcharacterisation, Dept. Mat. Sci. Univ. Erlangen, Germany) Microstructure and quality of photovoltaic thin films The Institute of Microcharacterization is working on the clarification of the relationships between properties and response of materials and their microstructures. Experimentally it thus uses modern analysis techniques with local resolutions down to atomic dimensions. It also operates the joint laboratory for high-resolution electron microscopy, because these methods are of general importance for all different classes of materials. The laboratory houses two transmission electron microscopes, high-resolution imaging and analytical ones. One of the major research areas of the institute concerns thin film photovoltaic materials and devices. The advantages of the thin film techniques, chiefly easy deposition, low process temperatures and integrated solar cell interconnections for very large solar panels, are contrasted by the fact that present day technologies cannot produce single crystalline layers, ie. the defect structure directly affects the electrical properties. Our work therefore supports the strategy to tolerate crystalline defects by finding processing conditions that minimize defect densities and prefer electrically inactive defects. We shall briefly consider results recently obtained from laser crystallized silicon and from evaporated chalcopyrites thin films. Most importantly we shall discuss results obtained with our new cathodoluminescence spectrometer that has been attached to our analytical transmission electron microscope. This new tool is almost exclusive in the amongst electron microscope laboratories worldwide and permits to analyse, in addition to structural and chemical properties, the optical response from the same nanodimensional site in a specimen.
Didier Hamm (Institute of Advanced Energy) Study of the transition in porous silicon formation regime This work studies the behaviour of the porous silicon layer growth when varying wafer resistivity (p-type) and current density. Under a constant anodising treatment the porous layer formation regime could be unstable and a transition from a homogeneous nanoporous layer to a filled macroporous layer can occur. The conditions for which the transition takes place are clearly established and proved that a tiny experimental change modifies drastically the morphology of the porous layer. A low current density and a high wafer resistivity favour the transition.
Monica Lopez (Thermosensorik GmbH, Erlangen, Germany) Non-destructive testing using infrared detectors
Waheed Badawy Solar Energy Conversion -'The Environmentally Safe Energy Source of the Near Future'- and our contribution to the field The considerable interest in the practical use of solar energy has increased the importance of photovoltaic and photoelectrochemical systems. Metal oxide films are known to form stable photovoltaic junction with semiconductors of practical relevance like silicon. Thin films of SnO2 and TiO2 were prepared easily and conveniently on the surface of silicon wafers by the spray pyrolysis technique. The prepared heterojunctions i.e. the Si/oxide junction represent the main part of stable and efficient solar energy converter. In these systems the solid/solid junction (n-Si/oxide) is separated from the site of the environmental interaction by the stable oxide film (SnO2 or TiO2) that protect the conventional semiconductor from photocorrosion. Beside its use in the fabrication of photovoltaic cells, the n-Si/oxide was used in the preparation of photoelectrochemical cells. The characteristics of the oxide film were subjected to a series of improvements either in the surface conductivity or the band gap energy i.e. the position of the Fermi level of the semiconducting oxide by incorporating foreign atoms in the oxide film matrix during its preparation. The improvement of the solar cells enables their use as clean energy converters. The fabricated solar cells have an efficiency up to 14%, an average open-circuit potential of ~-0.62 V and a short circuit current of 30 mA/cm2.
Hidaki Ohgaki (Institute of Advanced Energy) Design Studies of IR-FEL systems at IAE An infrared FEL facility is under construction at the Institute of Advanced Energy, Kyoto University. The electron beam of 25-40 MeV will be generated by an S-band linac with a thermionic RF gun. Numerical studies to estimate the electron beam parameters and expected FEL gain of the present system have been performed, and the results will be presented in this symposium.
Stefan Rosiwal (Chair for Materials Science and Technology, Dept. Mat. Sci. Univ. Erlangen, Germany) CVD-Diamond-Coatings on Silicon-Carbide-Bearings for Dry-Running-Conditions SiC-Rings were coated with CVD-diamond in an industrial scale HF-CVD reactor with a coating thickness of about 8 µm. Characterisation of the diamond coated sliding faces regarding three dimensional surface roughness (Sa), phase composition (micro raman) and microstructure (SEM) was performed in the as deposited state and after tribological testing. The tribological testing was carried out with the as-deposited substrates in a ring-ring geometry, coated surface running against coated surface. Standard test parameters were taken from industrial evaluation for tribological coatings in sliding bearings (0.03 - 7 m/s, 0.2 - 0.8 N/mm˛) in air (relative humidity 50 %, temperature 22 °C) with sliding distances in a selected test up to 18000 m. It is found that the wear debris plays a key role for the friction of these coatings.
Toshiteru Kii (Institute of Advanced Energy) Improvement of electron beam properties by reducing back-bombardment effects in a thermoionic RF gun In the Free Electron Laser (FEL) experiment, where long beam macro pulse is required, energy shift caused by increasing of current density at the cathode surface due to the heat up by back-streaming electrons is quite serious in thermionic RF gun. By applying transverse magnetic field, we succeeded in produce longer electron beam macro pulse. Comparison between experimental and numerical results will be discussed.
Heino Sieber (Chair for Glass and Ceramics, Dept. Mat. Sci. Univ. Erlangen, Germany) Biomorphous Ceramics In contrast to engineering materials, biological structures exhibit a hierarchically built anatomy, developed and optimized in a long-term genetic evolution process. They are characterized by a complex shape, with the structural features ranging from the micro (cell walls) to the macro scale (skeletons). Due to their unique structure-mechanical property relationships on a micro as well as on a macro scale biological materials have become of interest for advanced processing concepts of engineering materials in the recent years. Various biotemplating technologies have been developed for conversion of naturally grown plant structures into biomorphous ceramics, that offers the possibility to use the large variety of nature developments to produce microstructural designed materials, which are so far very difficult to manufacture by conventional techniques. Considerable efforts have been devoted to the preparation of dense, biomorphous SiSiC-ceramics by reactive Si-melt infiltration of pyrolysed wood preforms. Highly porous, cellular, single-phase SiC-ceramic were obtained by vapour phase reaction with different Si-containing gases. Porous, biomorphous oxide ceramics were manufactured by infiltration of biocarbon templates with metal-organic solutions, subsequent pyrolysis and sintering. The manufacturing of biomorphous ceramics will be described and their materials properties discussed for structural and functional applications.
Masahiro Yamamoto (Department of Energy and Hydrocarbon Chemistry) Molecular theory of electrified solid/liquid and liquid/liquid interfaces The chemistry of electrified solid|liquid and liqid|liquid interfaces is the main target of the electrochemistry. From the ordinary current-voltage relation we can get the monolayer level information of the interfaces. Recently using the spectroscopic methods more detailed information of the structure and dynamics of the phenomena of the electrified interface. On the other hand the theoretical studies on the electrified interfaces are basically classical thermodynamics level and are far behind the experiments mentioned above. This is because the interfacial phenomena include the multi-scale level, i.e. from quantum level for electrons at electrode to the continuum level of the double layer of mm size. In the present study I will show some examples to tackle on this multi-scale problem.
Gabi Schierning (Chair for Electrical Engineering Materials, Dept. Mat. Sci. Univ. Erlangen, Germany) Phosphors for x-ray detection Phosphor screens for the medical x-ray detection meet highest requirements: Good absorption of x-rays which is ensured by the use of elements with a high atomic number, stability of the defects built during x-irradiation even at room temperature to store the information until read-out, a clear spectral separation of stimulation light and stimulated emission, a high lateral resolution of the image plate, a stimulation wavelength at which a cheap laser is available, a sensitive and fast detection of the emitted light, complete erasurebility of the stored information, and a high reusability of the image plate (several thousand times of exposure to x-ray and to light). Up to now, the mostly used x-ray storage phosphor is BaFBr:Eu2+ and related systems as BaF1+xBr1-x-yJy:Eu2+ or Ba1-xSrxFBr:Eu2+. But new competitive materials appear, for examples CsBr:Eu2+. Assets and drawbacks of this new storage phosphor will be discussed.
Tsutomu Kodaki (Institute of Advanced Energy) Transcriptional regulation to adapt to environment changes It is well known that organisms have a variety of transcriptional regulation to adapt to the environmental changes. For example, a number of enzymes involved in the synthesis of phospholipids in the yeast Saccharomyces cerevisiae are known to be repressed on the addition of myo-inositol and choline to the culture medium (inositol-choline regulation). I will present an overview of this inositol-choline regulation including a molecular mechanism.
Christina Hack (Chair for Electrical Engineering Materials, Dept. Mat. Sci. Univ. Erlangen, Germany) Thin Film Solar Cells Based on Copper-Indium-Diselenid (CIS) Chalcopyrite semiconductors are promising absorber materials for thin film solar cell applications due to their high absorption coefficient. The most important compound is Cu(In,Ga)Se2 (CIS). In Germany the state of the art in CIS solar cell development is the installation of two pilot manufacturing facilities for the production of modules with monolithically integrated cells. To achieve further insight in the absorber properties and their dependence on formation or composition the Crystal Growth Laboratory is working on basic research studies of single crystals, homoepitaxial layers as well as modelling and optimisation of the industrial thin film process.
Masahiro Shioji (Graduate School of Energy Science) Analysis of Turbulent Flows by a PIV Measurement and an LES Calculation Repetitive measurement of cross-correlation PIV (Particle Image Velocimetry) using higher resolution images provided the turbulence characteristics in a round free air-jet. Another approach for analyzing the turbulent flow-field was made using LES (Large Eddy Simulation) calculation with the sub-grid scale model. The turbulence characteristics in the developed region well reproduced the measured one as long as the model constant was adequately selected. Further application works are still advanced to the simulation of the reacting flow and the unsteady jet.