High-performance, low-operating voltage, and solution-processable organic field-effect transistor with silk fibroin as the gate dielectric

We report the use of silk fibroin as the gate dielectric material in solution-processed organic field-effect transistors (OFETs) with poly(3-hexylthiophene) (P3HT) as the semiconducting layer. Such OFETs exhibit a low threshold of -0.77V and a low-operating voltage (0 to -3 V) compatible with the voltage level commonly-used in current electronic industry. The carrier mobility of such OFETs is as high as 0.21 cm(2) V-1 s(-1) in the saturation regime, comparable to the best value of P3HT-based OFETs with dielectric layer that is not solution-processed. The high-performance of this kind of OFET is related with the high content of beta strands in fibroin dielectric which leads to an array of fibers in a highly ordered structure, thus reducing the trapping sites at the semiconductor/dielectric interface. (C) 2014 AIP Publishing LLC.