Flexible contact-electrification field-effect transistor made from the P3HT:PCBM conductive polymer thin film

Abstract We have demonstrated a flexible force-controlled contact electrification field-effect transistor (CE-FET). The pn CE-FET was fabricated on a flexible PET (polyethylene terephthalate) substrate using the p-type poly(3-hexylthiophene) (P3HT), and the n-type phenyl-C61-butyric acid methyl ester (PCBM) films as a conductive channel in the CE-FET. The PEO polyethylene oxide (–CH 2 CH 2 O–, PEO) was then deposited on the surface of the conductive channel to act as a contact layer. When the mobile electrode was progressively touched with the PEO contact layer, a triboelectric potential was significantly created between them. This potential can self-generate a gate signal to modulate the charge carrier transport in the conductive channel of the CE-FET and thereby provide a prospective control of its output current. The PTFE (polytetrafluoroethylene, PTFE) and the porous SiO 2 film (made from the recycling rice husks) was used as a mobile electrode in the enhancement mode and the depletion mode of the CE-FET, respectively, in order to build in an inner electric field by the triboelectric potential between the contact layer and the mobile electrode. Through controlling the distance between the two frictional layers, the output current of the pn CE-FET can be dramatically modulated from 2.84 nA to 62.31 nA in the enhancement mode, while that of the current can be controlled from 17.26 nA to 2.84 nA in the depletion mode. The pn CE-FET has provided high perspectives and opportunities for the flexible electronic devices applications in future.