著者

Tsuji Masaki Takahashi Yuki Sakurai Yuki Yomogida Yohei Takenobu Taishi Iwasa Yoshihiro Marumoto Kazuhiro

出版者

American Institute of Physics

雑誌

Applied physics letters (ISSN:00036951)

巻号頁・発行日

vol.102, no.13, pp.133301, 2013-04

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Magnetic interactions and magnetism of high-density charges in a polymer transistor were investigated by electron spin resonance (ESR). The anisotropy of the ESR spectra indicated an edge-on molecular orientation and the existence of two-dimensional magnetic interactions between the spins of the charges, reflecting high charge density. The voltage dependences revealed that the magnetism of charge carriers changed from paramagnetic to nonmagnetic as charge density increased. These results provide insight to the charge transport mechanism of polymer semiconductors with high charge densities.

著者

Tanaka Hisaaki Watanabe Shun-ichiro Ito Hiroshi Marumoto Kazuhiro Kuroda Shin-ichi

出版者

American Institute of Physics

雑誌

Applied physics letters (ISSN:00036951)

巻号頁・発行日

vol.94, no.10, pp.103308, 2009-03

被引用文献数

33 17

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Charge carrier concentration in operating field-effect transistor (FET) of regioregular poly(3-hexylthiophene) has been directly determined by electron spin resonance (ESR). ESR signals of field-induced polarons are observed around g=2.003 under the application of negative gate-source voltage (Vgs). Upon applying drain-source voltage (Vds), ESR intensity decreases linearly in the low Vds region, reaching to about 50% of the initial intensity at the pinch-off point (Vds~=Vgs). For larger absolute values of Vds, it becomes nearly Vds independent. These behaviors are well explained by the change in the carrier concentration obtained by the FET theory using gradual channel approximation.