Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2016: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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Outline of Final Research Achievements |
Electronic states and transport mechanisms of charge carriers in thin-film transistors (TFTs) of organic semiconductors have been investigated microscopically by using electron spin resonance spectroscopy. We designed a TFT structure with an ionic-liquid gate insulator, which enabled the high-density carrier injection, in order to control the electronic state of conducting polymers with high crystallinity. In highly-doped polymer films, we clearly demonstrated the formation of metallic state in crystalline regions, whereas the macroscopic conductivity showed semiconducting behavior at low temperatures due to the effect of traps. In the case of TFTs using thienothiophene-based small molecules as high-mobility semiconductors and solid gate insulators, presence of highly mobile carriers down to 4 K was demonstrated within the crystalline grain, whereas the macroscopic conductivity was limited by the carrier trapping at the grain boundaries.
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