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 $5\mathrm{V}$ ) and high current output (up to $10\mathrm{mA}$ or $4\mathrm{A}∕{\mathrm{cm}}^2$ ) and an ON/OFF ratio of $4\times {10}^6$ . 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.