Unique architecture and concept for high-performance organic transistors

We report an organic transistor with a vertically stack structure, which consists of a layer-by-layer active cell (drain/organics/source) on top of a capacitor cell (source/dielectrics/gate); the middle source electrode is shared by the capacitor cell and active cell. Three unique characteristics of this transistor, (a) its very thin and rough middle source electrode; (b) its capacitor cell with high charge-storage capability, allow the active cell to be influenced when the gate is biased; and (c) the large cross-section area and small distance between the source and the drain allow current flowing between the source and drain electrodes. Devices have been fabricated by thermal evaporation with the source-drain current well modulated by the gate potential. We have achieved organic transistors with low working voltage (less than 5 V) and high current output (up to 10 mA or 4 A/cm(2)) and an ON/OFF ratio of 4x10(6). A model is proposed for the device operation mechanism. The demonstrated device with its enhanced operating characteristics may open directions for organic transistors and their applications. (C) 2004 American Institute of Physics.