A solid state platform has been designed and fabricated that allows characterization of candidate organic semiconductor materials used in organic field-effect transistors (OFET). A systematic experimental protocol has been outlined that allows the separation of contribution of contact resistance and of the organic film resistance to the overall response. It has been shown that in co-planar OFET structures both components can be modulated by the gate electric field and that the magnitude of drain contact resistance modulation is comparable to that of the organic semiconductor. The correct identification of the origins of field modulation is crucial for design and optimization of these devices.
Purdue University, West Lafayette, IN