Figure 2: DOFET operation.
Two-dimensional numerical simulations. The applied voltages are VG=−5.1 V, VS=0 V, VD=−1 V, VCS=−60 V, VCD=−60 V. Geometrical and physical parameters are listed in the Supplementary Fig. 1 and in the Methods section, respectively. (a) Charge concentration in the organic semiconductor. The white arrows depict the charge injection from the source and drain electrodes into the semiconductor when the control source and control drain electrodes are biased. The x-to-y scale ratio is 1:200. (b) Quasi-Fermi potential at y=99 nm with (full line) and without (dashed line) CS/CD. Without CS/CD about half of VDS drops at the source and it is required for the charge injection. (c) Current density: x-component JX (black area) is equal to 1 A cm−2, and the y-component JY is shown with colour scale levels. (d) Current density JY and electric field EY along the y-direction at x=3.5 μm. In the range y=[0–47] nm, the current is driven by the diffusion, and in the range y=[47–100] nm, the current is driven by the drift. (e) JY and EY along the y-direction at x=20.5 μm. In the range y=[0–47] nm, the current is driven by the drift, and in the range y=[47–100] nm, the current is driven by the diffusion.
