Better bottom contact properties in organic field-effect transistors with ultrathin layers

Organic field-effect transistors (OFETs) are very promising to realize cheap electronics for mass production. Structuring the electrodes of OFETs directly onto organic semiconductors is often prohibited, while substrates with prepatterned electrodes disturb organic film growths at the electrodes resulting in low contact quality. We report on the observation that thiophene-based ultrathin organic layers, in the monolayer range, exhibit smoother and more uniform growth characteristics close to gold contacts when compared to thicker organic layers. As a result, these ultrathin layers in bottom contact configuration exhibit superior electrical contact properties. (c) 2005 American Institute of Physics.