Micrometer-scaled OFET channel patterns fabricated by using PEDOT/PSS microfibers

作者：Yan Hu^*; Kagata Tsubasa; Okuzaki Hidenori

来源：Synthetic Metals, 2009, 159(21-22): 2229-2232.

DOI：10.1016/j.synthmet.2009.07.033

• PEDOT/PSS
• Microfiber
• OFET
• Pentacene
• SAM
• STEM

We have easily fabricated channel patterns of organic field-effect transistors (OFETs), in which channel lengths were 5 mu m, by using wet-spun poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) microfibers with diameters of ca. 5 mu m. Pentacene-based FETs with a top-contacted configuration, showed a hole mobility of 0.13 cm(2) V(-1) s(-1) and on/off current ratio of 9.4 x 10(4). The device also showed large current of ca. 160 mu A (V(D) = -50V; V(G) = -50V), reflecting shorter channel length of the devices. We have evaluated self-assembled monolayer (SAM) through measurements of water contact angle and by Zisman plot. As a result. critical surface tension of the octadecyltrichlorosilane(OTS)-treated SiO(2) surface is 17 mN m(-1) which is consistent with that of well-known SAM. We also well analyzed the cross-sections of the device by a scanning transmission electron microscopic (STEM) technique. The results indicated that the thicknesses of the pentacene layer in the channel part and Au layer in the source/drain part were ca. 30 and 30 nm, respectively. Furthermore, it is also indicated that the 100-nm grains of the pentacene were well adhered on the surface of the SAM-formed SiO(2) layer.

• 出版日期2009-11