High-Performance Vertical Organic Transistors of Sub-5 nm Channel Length

Miniaturization of electronic circuits increases their overall performance. So far, electronics based on organic semiconductors has not played an important role in the miniaturization race. Here, we show the fabrication of liquid electrolyte gated vertical organic field effect transistors with channel lengths down to 2.4 nm. These ultrashort channel lengths are enabled by using insulating hexagonal boron nitride with atomically precise thickness and flatness as a spacer separating the vertically aligned source and drain electrodes. The transistors reveal promising electrical characteristics with output current densities of up to 2.95 MA cm^-2 at -0.4 V bias, on-off ratios of up to 10⁶, a steep subthreshold swing of down to 65 mV dec^-1 and a transconductance of up to 714 S m^-1. Realizing channel lengths in the sub-5 nm regime and operation voltages down to 100 μV proves the potential of organic semiconductors for future highly integrated or low power electronics.