Fast switching characteristics in vertical organic field effect transistors

We report a theoretical and experimental investigation of the switching characteristics in patterned-source vertical field effect transistors. Experimentally we show that the layered structure gives rise to capacitances coupling of the potential between the drain and source electrodes. By removing the extrinsic gate-source capacitance we are able to demonstrate unprecedented sub-2 μs switching and current levels of 3 A/cm². Theoretically, using a 2D drift-diffusion model, we show that the intrinsic response depends on two processes: the formation of the virtual electrode and the injection through it to form the vertical channel. The importance of the source structure parameter to achieve ultimate speed is discussed.