Dual-gate organic thin-film transistors

A dual-gate organic thin-film transistor is realized using solution-processed organic semiconductor and insulator layers. Electrodes are made from gold. Compared to conventional single-gate transistors, this device type has a higher on current and steeper subthreshold slope. We show that the improved performance is the result of a nonconstant threshold voltage rather than formation of a second accumulation channel. Formation of a second accumulation channel does occur but the field-effect mobility associated with this channel is a factor 10(4) lower than the primary channel due to the relatively rough insulator-semiconductor interface. (C) 2005 American Institute of Physics.