Liquid-Gated Organic Electronic Devices Based on High-Performance Solution-Processed Molecular Semiconductor

High-mobility organic semiconductors such as [1] benzothieno[3,2-b] benzothiophene (BTBT) derivatives are potential candidates for ultrasensitive biosensors. Here 2,7-dioctyl BTBT (C8-BTBT-C8)-based liquid-gated organic electronic devices are demonstrated with two device architectures, viz. electrolyte-gated organic field-effect transistor (EGOFET) and electrolytegated organic synapstor (EGOS), and different electrode materials, viz. gold and poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS). EGOFETs exhibit a mean transconductance of about 45 mu S, on a par with literature, and a max value up to 256 mu S at the state-of-the-art in aqueous electrolyte, with a mean product of charge mobility and effective capacitance of about 0.112 and 0.044 mu S V-1 for gold and PEDOT: PSS electrodes, respectively. EGOSs exhibit a dynamic response with 15 ms characteristic timescale with Au electrodes and about twice with PEDOT: PSS electrodes. These results demonstrate a promising route for sensing applications in physiological environment based on fully solution-processed whole-organic electronic devices featuring ultrahigh sensitivity and fast response.