A large shift of the localized surface plasmon resonance (LSPR) spectrum of gold nanoparticles was attained by electrochemical oxidation of the nanoparticle surface. This oxidation occurred in the cell, which consisted of a pair of indium tin oxide (ITO) electrodes and water medium between the electrodes. On one side of the ITO electrode, the gold nanoparticles were adsorbed. With the application of a voltage of 5 V to the cell, a spectrum shift as large as 68 nm was obtained. Though the spectrum shift has already been observed by changing liquid crystal (LC) orientation surrounding gold nanoparticles, the size of the shift was not large (11 nm). That was because the variation of the effective refractive index of LC was rather small. Our large shift due to electrochemical oxidation resulted from the large refractive index of Au-O. The electrochemical oxidation was confirmed by XPS analysis of the gold nanoparticles with the LSPR spectrum shift. Other possible mechanisms of the shift such as charge localization, aggregation, and adsorption of charged materials proved to have no effect via SEM measurement and so on. This large shift of the resonance spectrum can be expected to lead to further development of spatial light modulators for next-generation optical communications and displays.

The power conversion efficiency (PCE) of organic photovoltaic (OPV) modules with 9.5% (25 cm2) and 8.7% (802 cm2) have been demonstrated. This PCE of the module exceeded our previous world records of 8.5% (25 cm2) and 6.8% (396 cm2) that were listed in the latest Solar Cell Efficiency Tables ver.43 [1]. Both module design and coating/patterning technique were consistently studied for module development. In order to achieve highly efficient modules, we increased the ratio of photo-active area to designated illumination area to 94% without any scribing process and placed insulating layers in order to decrease the leakage current. The meniscus coating method was used for the fabrication of both buffer and photoactive layers. This technique ensures the fabrication of uniform and nanometer order thickness layers with thickness variation less than 3%. Furthermore, the PCE of the OPV under indoor illumination was found to be higher than that of the conventional Si type solar cells. This indicates that OPVs are promising as electrical power supplies for indoor applications. Therefore, we have also developed several prototypes for electronics integrated photovoltaics (EIPV) such as electrical shelf labels and wireless sensors embedded with our OPV modules, which can be operated by indoor lights.

We demonstrated high-brightness large-area, white organic lightemitting diode (OLED) consisting of printing-processed organic semiconductor layers. Meniscus printing process was applied to the substrate with 2 μm-high stripe-shape auxiliary electrodes. The OLED panel showed white emission all over the whole emitting area of 58 mm × 52 mm, high average luminance of 10,000 cd/m 2 , luminance uniformity of 40 %, and high luminous flux of 95 lm.

The triboelectrification between iron carrier beads and polystyrene films molecularly‐doped with 50 electron‐donative organics are investigated in a nitrogen atmosphere and low humidity (<10% RH) conditions. The electrochemical oxidation potential of the dopants correlates well with the tribocharging amount within the framework of a homologous series of dopant molecules, but turns out not to be a widely applicable and reliable indication. Considerations of liquid‐phase electrochemical oxidations and solid‐phase frictional electrifications lead us to use calculated oxidation potentials instead of the measured one, and it is revealed that a relatively good relation holds between the calculated potential and the charging amount. However, there still exists some dispersion of the data in the relationship. X‐ray photoelectron spectroscopic measurements of the film surfaces, combined with the above findings, reveal that the dopants form charge transfer complexes with environmental dioxygen and that they serve as the positive‐charging sites. This is evidenced by an even more reliable relationship between the charging amount and the binding energy of O1s electrons. A possible mechanism is proposed for the positive charging of organic compounds on the basis of the charge‐transfer model.

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Large shift of localized surface plasmon resonance (LSPR) spectrum of gold nanoparticles was attained by electrochemical oxidation of the nanoparticle surface. This oxidation occurred in a cell consisting of a pair of indium tin oxide (ITO) electrodes with water medium between the electrodes. On one side of the ITO electrode, the gold nanoparticles were adsorbed. The LSPR spectrum was moved consecutively to the red by increasing the applied positive voltage. By the application of 5 V to the cell, the spectrum shift as large as 55 nm was obtained. Though the spectrum shift has already been observed by changing liquid crystal (LC) orientation surrounding gold nanoparticles, the amount of the shift was not large (11 nm). That was because the variation of the effective refractive index of LC was rather small. Our large shift due to electrochemical oxidation resulted from the large refractive index of Au-O. The upper limit of the LSPR spectrum shift by our method is estimated to be 138 nm.

A noncontact squeegeeing device is used just after the development process in a liquid toner electrophotographic printing system. By using capillary forces, this device removes almost all of the surplus liquid adhering to the photoreceptor surface. Though the device has a simple structure and has even been used in actual systems, there is not much information regarding the mechanism of the device available in the literature, and the mechanism does not seem to have been theoretically analyzed. In this paper, some equations are derived from the lubrication approximation theory based on the condition that total liquid flow is zero. The calculation results obtained using these equations show good agreement with the experimental results for the variation of the characteristics of the squeegeeing efficiency with the circumferential surface velocities of rollers. The proposed equations make the calculation of the squeegeeing characteristics easy and thus facilitate improvement of the device and further development of the system.