Design of ion-gated transistor materials at the molecular level

Ion-gated transistors (IGTs) are iontronic devices in which the channel layer is in direct contact with the electrolyte, exploiting the coupled nature of ionic and electronic fluxes. This feature enables them to provide efficient gate -channel capacitance coupling and act as low-voltage transducer amplifiers and interactive interfaces between biology and electronics. In this paper, we first discuss the basic mechanism of ion gating. We review different types of organic materials employed as channel layers. Specifically, we provide insights into the design strategies of channel materials at the molecular level to elucidate how this can be related to device performance. We also highlight several electrolyte materials because their chemical structures and interactions with the channel layer at the nanoscale play a key role in regulating the operation of IGTs. Subsequently, we summarize the promising applications in biochemical detection involving material self-assembly. Finally, we present the challenges and perspectives for the development of IGTs.