Flexible low-voltage organic transistors with a transit frequency of 40 MHz and an on/off current ratio of 10 orders of magnitude

Organic thin-film transistors (TFTs) are of interest for flexible displays, sensors, and circuits. For all these applications, the TFTs must have a large on/off current ratio and a high transit frequency. A major challenge is to simultaneously maximize the on/off ratio and the transit frequency, because a high transit frequency requires a small channel length, which often leads to short-channel effects, including a large off-state drain current. Here, we lift this fundamental compromise and demonstrate organic TFTs that exhibit a complete absence of detrimental short-channel effects for channel lengths down to 300 nm, making it possible to simultaneously achieve the largest on/off current ratio (10¹⁰) and the highest transit frequency (40 MHz) reported to date for flexible organic TFTs, despite the fact that these TFTs operate at very low voltages (≤3 V). These organic TFTs therefore meet the fundamental static and dynamic performance requirements for flexible, high-frequency, low-voltage, low-power electronic systems.