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A high-performance vertical-type organic transistor has been fabricated using bis(l,2,5-thiadiazolo)-p-quinobis(l,3-dithiole) (BTQBT) for the channel layer. The BTQBT molecules are oriented horizontally, with the molecular plane of each monolayer parallel to the substrate. The π-π stacking direction of the BTQBT molecules is aligned with the carrier transport direction in this vertical transistor. The modulated drain current density exceeded 1 A cm-2 upon the application of a gate voltage of less than 5 V. In addition, the device exhibits a high on/off current ratio of over 105. [ABSTRACT FROM AUTHOR] more...

Colorectal cancer is one of the most malignant neoplasms worldwide. Fucoxanthin is a carotenoid present in the chloroplasts of brown seaweeds. In the present study, the anticancer effects of fucoxanthin and its metabolite, fucoxanthinol, on 6 colorectal cancer cell lines and 20 tissue samples from surgically resected clinical colorectal cancer specimens were examined using a collagen-gel droplet embedded culture drug sensitivity test (CD-DST). The in vitro sensitivity to fucoxanthin, fucoxanthinol and the anticancer drugs is expressed as T/C (%), where T is the absorbance of cells which stained by neutral red treated with carotenoids and C is the absorbance of non-staining cells. Fucoxanthin and fucoxanthinol decreased the T/C (%) of Caco-2, WiDr, HCT116, and DLD-1 cell lines at doses of 20 µM. Fucoxanthinol also decreased the T/C (%) of SW620 cells, while the T/C (%) of Colo205 cells was not reduced by treatment with either carotenoid. Specifically, the T/C (%) of Caco-2 and WiDr cells, which were incubated in carotenoid-free medium for 6 days following treatment with 20 µM fucoxanthinol for 24 h, was markedly decreased to 1.4±0.2 and 12.0±0.3%, respectively. Furthermore, fucoxanthin and fucoxanthinol decreased the T/C (%) in colorectal cancer tissue samples. Notably, 20 µM fucoxanthinol treatment resulted in a higher proportion of colorectal cancer samples with a T/C (%) of <50% (13/20, 65%) compared with samples treated with 20 µM fucoxanthin (2/20, 10%). The median T/C (%) value of 35.1% for the 20 cancers specimens treated with 20 µM fucoxanthinol was lower than the median T/C (%) values of 86.3% and 75.8% for those treated with fluorouracil and paclitaxel, respectively. These results suggested that fucoxanthin and fucoxanthinol may be of use as chemotherapeutic agents in colorectal cancer. [ABSTRACT FROM AUTHOR] more...

We propose time-domain reflectometry as an effective tool to investigate the dynamics of electronic devices. We use this technique to experimentally detect with 10 ns time resolution the dynamic process of carrier injection from the contact electrode into an organic thin film transistor as a time evolution of the device impedance. This method allows us to trace vertical carrier injection in the thickness direction. [ABSTRACT FROM AUTHOR] more...

Self-assembly silver nanoparticles were successfully prepared on indium tin oxide coated glass substrates by means of a vacuum vapor evaporation method followed by thermal annealing. The nanoparticles were characterized using a field-emission scanning election microscopy with an energy dispersive X-ray analyzer and a UV–vis spectrometer. It was found that the particle morphology was drastically changed depending both on the evaporated silver mass thickness and the length of time of the thermal annealing. Some absorption peaks were observed in the UV–vis spectra and the peaks showed red-shift with the average particle size increase. These facts suggest that the absorption peaks may arise from the localized surface plasmon resonance. These controllable absorptions may be suitable for photon management in dye sensitized solar cells. [ABSTRACT FROM AUTHOR] more...

We have demonstrated NAND and NOR logic circuit operations of stacked-structure complementary thin-film transistors (TFTs) using 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) and soluble ZnO as active layers. Bottom-gate-type TIPS-pentacene TFTs, as p-channel transistors, were formed on n-channel ZnO TFTs with common gate electrodes. Solution-processed silicone-resin layers were used as gate dielectric and electrical interconnection layers between lower and upper TFTs. The stacked-structure integrated circuits have several advantages such as ease of active layer formation, compact device area per stage, and the short length of the interconnection compared with the planar configuration in a conventional logic circuit. [ABSTRACT FROM AUTHOR] more...

Wet processed ZnO films for semiconductor layers bring positive impact on fabrication of field-effect transistors (FETs) in terms of their low process temperature and manufacturing cost reduction. In our work, with the aim of fabricating organic light-emitting transistors (OLETs) using transparent ZnO FETs as the driver transistors, we have fabricated a wet processed ZnO film as a semiconductor layer, and investigated the effects of ultraviolet/ozone (UV/O3)-assisted thermal treatments on ZnO FET characteristics. The results on the carrier mobility and thermal treatment temperature of ZnO films showed that the carrier mobility is almost proportional to treatment temperature, and the UV/O3-assisted thermal treatment lowers the thermal treatment temperature. Moreover, devices subjected to UV/O3-assisted thermal treatments showed excellent electrical characteristics compare with devices without the treatments. These results show that the UV/O3-assisted thermal treatment is expected to facilitate OLET fabrication on flexible plastic films. [ABSTRACT FROM AUTHOR] more...