Sub-micron Channels

Experimentally it is found, that for channels smaller than 500 nm the gap is filled with contact-related organic material and the 2D layer-by-layer growth of DH4T is therefore hindered. The growth of the organic material is then electrode dominated. This behaviour is clearly seen in Figiue 22.18. 

In conclusion, oscillations observed in the mobility as well as in the contact resistance are related to the layer-by-layer growth inside the free area of the channel which is not influenced by material diffusion from the contacts. Below 500 nm (for DFI4T and DFI5T) a different growth mode is observed by electrical measiuements and by AFM imaging. A transition towards electrode dominated growth is found. 

New applications of organic transistors demand increased switching speed which might be achieved mainly either by new materials or by reduced dimensions of the device. For cheap production, materials are usually limited to those processible from solution. In this section we will follow the second route of reduced dimensions and restrict the material basis to oligio- and polythiophenes, i.e. DH7T and rr-P3HT. 

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Stranski-Krastanov growth mode 219 sub-micron channels 485 substituted oligothiophenes 474 substrates - passivation 442 substrates - Si02 substrate 429 surface... 

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