Resolving the contact voltage dilemma in organic field effect transistors

In spite of the great interest in organic field effect transistors, many of their aspects are still not well understood. In particular, efforts to uncover the origin of the contact resistance and the underlying physics have lead to apparently contradictory results. Here we show that all these features can be understood by a unified description that takes into account thermionic emission with diffusion-limited injection at the source contact and space-charge limited conduction near it. Moreover, the usual field effect transistors behavior at a certain distance from the source and the conduction in the depletion region emerge not as ad hoc assumptions but directly from the proposed mechanisms.