Beyond 10 MHz/V High Speed All-Vertical Electrochemical Transistor

Organic electrochemical transistors (OECTs) have emerged as promising candidates for next-generation biosensing device due to their remarkable transconductance, low threshold voltage and good bio-compatibility. However, OECTs had to have a slow driving speed due to its unique operating principle, which have been pointed out as a disadvantage of OECTs. We propose another approach for overcoming this obstacle. Moreover, since most OECTs perform electrolyte gating, gating with Ag/AgCl reference electrode is common, therefore scalability was often not good. An all-vertical OECT architecture enable outstanding fast operating speed, and also enables to expansion of large-area and high-density OECTs. Simple approach for implementing the patterned Ag/AgCl reference electrode could be an answer for the scalability. As a result, 14 MHz/V operation frequency was yielded, which is the highest value for OECTs reported to date.