Solution-based silk fibroin dielectric in n-type C60 organic field-effect transistors: Mobility enhancement by the pentacene interlayer

A pentacene interlayer of 2 nm thick is inserted between fullerene (C60) and the solution-based silk fibroin dielectric in C60 organic field-effect transistors (OFETs). The pentacene interlayer assists to improve crystal quality of the C60 layer, leading to the increase of field-effect mobility (μFE) from 0.014 to 1 cm2 V−1 s−1 in vacuum. The μFE value of the C60 OFET is further enhanced to 10 cm2 V−1 s−1 when the OFET is exposed to air in a relative humidity of 55%. Generation of mobile and immobile charged ions in solution-based silk fibroin in air ambient is proposed.