[21p-W521-1~18] 12.4 Organic light-emitting devices and organic transistors

[21p-W521-12] ESR studies of ion gel-gated ambipolar organic thin-film transistors under high charge density

〇Shohei Iguchi¹, Yuki Sakurai¹, Naohiro Fujita¹, Kazuhiro Marumoto^1,2 (1.Division of Materials Science, Tsukuba Univ., 2.TIMS, Tsukuba Univ.)

Keywords:organic transistor,ESR,ion gel

Organic thin-film transistors (OTFTs) have attracted much attention owing to their potential as switching components in organic electronic circuits. Among organic transistors, ambipolar transistors have attracted interest in the area of fundamental science in organic semiconductors and in the area of device applications as light-emitting transistors and complementary metal-oxide semiconductor (CMOS)-like logic circuits. However, the carrier balance between hole and electron carriers in ambipolar transistors is an important problem for the practical use. In this study, we report an electron spin resonance (ESR) study of ambipolar organic thin-film transistors with ion gels to investigate the differences in characteristics between hole and electron carriers in devices from a microscopic viewpoint. We fabricated an organic thin-film transistor with asymmetric source/drain electrodes using organic semiconductors such as pentacene. From the ESR analysis, it is suggested that differences in behaviors between hole and electron carriers come from the difference in energy levels at metal/semiconductor interfaces.