Modelling of saturation current of an organic field-effect transistor with accounting for contact resistances

The saturation current of an organic field-effect transistor was calculated numerically by bisection method taking into account the source and drain resistances. Dependences of the saturation current as a function of the gate voltage, centred on the threshold voltage, and as a function of the "extrinsic" (taking into account the source and drain resistances) saturation voltage are presented. The calculations were carried out using an iterative scheme assuming the saturation current to be zero for iteration zero and using different numbers of iterations. In addition, we carried out a compact modelling of the saturation current in the framework of the approach we proposed earlier. It is shown that when in the equation for the compact modelling initial value of saturation current of zero value (corresponding to zero iteration) is used, a good agreement with the bisection method of over a wide range of gate voltages is obtained.