Patent ID: 7646013

Claim:
A field-effect transistor device comprising: an organic semiconductor layer; a source electrode arranged in electronic contact with said organic semiconductor layer; a drain electrode arranged in electronic contact with said organic semiconductor layer; a gate electrode; and an electrolyte layer, which is arranged between said gate electrode and said organic semiconductor layer, and which includes molecular, oligomeric, polymeric or dendrimetic electrolyte which includes a medium further including ions having a dissociation constant of at least 10 −8 in said medium, wherein the field-effect transistor device is configured so that a current between said source and drain electrodes within said organic semiconductor layer is primarily controlled by means of a polarization of said electrolyte layer, which induces charge carriers in said semiconductor layer, the field-effect transistor device is configured so that the electrolyte is dissociated into at least a small ion-complex having a first electric charge; and a large ion-complex having an opposite electric charge to said first electric charge, and wherein the larger ion-complexes, due to their size, are prevented from penetrating into said organic semiconductor layer, at least when a control voltage is applied to said gate electrode.