High performance N-type organic thin-film transistor based on biocompatible silk fibroin: poly(vinyl alcohol)-blended dielectric layer

Abstract

We investigated the effect of biocompatible silk fibroin (SF):poly(vinyl alcohol) (PVA) blended dielectric layers on the characteristics of N-type organic thin-film transistors (OTFTs). The OTFT with high performance and low driving voltage (4 V) are obtained. Compared with those with pure SF dielectric layer, a high on/off ratio of ∼ 103 and enhanced field-effect mobility of 0.203 cm2/Vs of OTFTs were obtained, by controlling the weight ratio of SF:PVA blends to 7:5. The mechanism of performance improvement of OTFT was systematically studied through the morphology characterization of dielectrics by utilizing atom force microscopy and electrical characterization. The smooth and homogeneous morphology of blend dielectrics having lower charge carrier trap density, is the main reason for the OTFTs based on SF: PVA-blended dielectric exhibited a higher performance than those based on pure SF dielectric.