DC Compact Model for Subthreshold Operated Organic Field-Effect Transistors

To accurately describe the electrical behaviors of organic field-effect transistors (OFETs) across the whole subthreshold regime, a compact model considering both non-exponential gate-voltage-dependent diffusion current and additional drift current is developed. The two current components in the subthreshold regime are combined into one closed-form expression with a hyperbolic tangent transition function. By fitting transfer and output curves in the subthreshold regime at different bias voltages, the model is shown to be applicable to OFETs in different materials and device structures of large and small subthreshold swings. The model is further demonstrated continuity with the OFF-state and above-threshold regimes when being incorporated into a commercial SPICE simulator for circuit simulations.