[23p-E206-1~13] 12.4 Organic light-emitting devices and organic transistors

[23p-E206-2] Probing the gate bias-stress effect in OFETs by sum-frequency generation spectroscopy

〇(M2)Naoya Ohashi¹, Takeaki Isobe¹, Yuya Tanaka^1,2, Hisao Ishii^1,2,3, Takayuki Miyamae^1,3 (1.GSSE, Chiba Univ., 2.CFS, Chiba Univ., 3.MCRC, Chiba Univ.)

Keywords:organic field-effect transistor, gate bias-stress effect, sum-frequency generation spectroscopy

In this study, we prepared two types of bottom-gate top-contact organic field-effect transistors (OFETs) fabricated with different BTBT derivatives: one was fabricated with 2,7-diphenyl[1]benzothieno[3,2-b][1]benzothiophene (DPh-BTBT), and the other was fabricated with 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C₈-BTBT). The DPh-BTBT film was deposited by vacuum thermal evaporation and the C₈-BTBT film was fabricated by blade coating method. Relatively large bias-stress effect was observed in the current-voltage measurements of the OFET fabricated with DPh-BTBT. Then, channels of OFETs under different gate voltage conditions were probed by using of sum-frequency generation spectroscopy. As a result, we succeeded in probing changes in the internal electric field due to charge traps at the interface of OFET. We discuss the correction between bias-stress effect and charge traps at the dielectric/semiconductor interfaces.