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

Abstract

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 electrolyte‐gated 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 µS, on a par with literature, and a max value up to 256 µS 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 µS 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.